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New Member FD Speedo doesn't move and odo doesn't count
Hi all,
Having an issue with the speedo and odometer on my '94 FD. The speedo doesn't move, not matter how fast or slow. To go along with that the odometer doesn't log any miles. Now, I don't really have an issue not logging miles since I don't intend to ever part with this car (I've had it since '99), but the speedo not doing anything...that is more of an issue. Sure, I can use a GPS app on my phone and get by, but that is kind of a pain. The funny thing is, the tach works just fine.
I have nearly the entire interior stripped down right now (save the heater core) so I have a lot of access to stuff.
I'm looking for any thoughts on what to be looking at.
I have yet to take the speedo dial off the speedo circuit board, but otherwise I have lots of pictures.
Once we get your post count up, I'll merge this thread into the main troubleshooting the FD speedometer thread. I have not seen this problem before so this would be a good case study!
When did the speedometer stop working? Was it after you removed the instrument cluster for something else or did it stop working out of the blue? If any work was previously done to the instrument cluster, did you remember to connect the 15-pin ribbon cable to the speedometer? If not, then you wouldn't see the tach or speedo move.
Does your odometer actually show mileage or is it a blank screen? Additionally, do you see the backlight to the odometer? It should be amber in color and subdued but visible.
If the speedo needle does not move then I'd like for you to check the Vehicle Speed(Speedometer) Sensor (VSS). The test for it can be found in the BEM (Body Electrical Troubleshooting Manual). Look for Flowchart #2, Symptom: Speedometer does not operate. It should be on Pg C1-8 (PDF Pg 10) of the BEM.
Of note about the above flowchart, you will be checking for a voltage at the referenced pins. In order to test the sensor while plugged in, the rear wheels must be off the ground. Ensure the car is adequately supported and secured from movement. Turn the ignition switch to the ON position but do NOT start the car. Place the car in neutral and have the e-brake down. Then have an assistant help rotate the rear wheels slowly.
This flowchart will verify the wiring from the VSS to the instrument cluster and the VSS.
I'll also make some observations from the photos you posted shortly. I can tell you that someone has already removed the speedometer face before.
Report back your observations from Flowchart #2 when you are ready.
After reviewing your photos, here are my observations:
The yellow box is the Speedometer connector, CON1. Please verify the flex print is properly seated and secured by the push-down clip. The green box is the 3-Series connector where you need to measure the VSS voltage.
The red box shows what looks like burn marks around the solder joint. This is 1 of 4 solder joints to the speedometer face. It must be de-soldered then soldered in place when necessary. It looks like someone else removed the speedometer face then reattached it. Otherwise, it could be left over flux from the original solder job that was not removed.
Take a closer look at these 2 capacitors, C4 and C6. Their tops look bulged out, which is a sign of replacement. Take a closer photo then post. Take another look at IC3. It looks crooked. Verify that each leg does not touch one another. This chip stores the odometer reading. If it looks ok then don't mess with IC3!
Take a closer look at these 2 capacitors, C16 and C17. Their tops looks bulged out, especially C17. Again, this is a sign of replacement.
This is a different angle that shows capacitors C2 (left) and C4 (right). Take closer photos and verify their tops are flat or bulged out.
Does this help shed some light? Take closer photos of the suspect components then report back.
I'll start with the history. I purchased the car in December of '98. I have been the only owner of it since then. I have had it repaired professionally twice. Both times in '99. Once to have the clutch replaced and once to have the water pump replaced. It had about 22k miles on it then. Over the next 10 years I drove it a decreasing amount as I got married and started having kids. It spent nearly all of those winters in a garage. In the fall of '09 we moved house and I no longer had a garage big enough to store it at home over the winter. So it went into a barn for the winter. While on the drive to the barn in '09 I noticed that he speedo wasn't working. So to answer the first question you had, I first noticed that the speedo was done in '09. It seemed to happen out of the blue.
Well, one winter became 9 winters, 2 kids became 3 kids, and it wasn't until the barn owner called last September that it came back out of the barn. Needless to say, it smelled badly of mouse.
Last October I went through the effort to find out just how bad the situation was. After replacing the oil, coolant, spark plugs, and battery it was running again. No electrical issues. Just a lot of smelly carpet, floor mats, etc.
It spent the winter in my garage, and come this spring I changed the tranny and diff fluid and put a few hundred miles on it.
At the end of August the power steeing pump bearing started making a terrible noise so I made the decision to retire it for the summer and dig into some of the remaining items I had for it.
Out came the power steering pump, the guage cluster, the dash, all the interior trim, the carpet. Out also came a bunch more mouse nest. I even popped open the heater core and had to get mouse nest out of there. I have no idea who would have taken the cluster out before me since I'm the 2nd owner, but maybe before me in '98. I had it out of the cluster earlier and had put it back together before taking back apart to take all the photos. I did not remove the speedometer face, just took the whole thing out to have a look at the state of the caps. Again, my circuit board expert (literally that is what he does all day for work, not just a friend who plays around), had a look at it today and didn't see any components that looked off. The odometer shows numbers and is well lit. I have a photo from last fall, but you can take my word that it showed numbers was bright.
You'll have to give me time to do the test, as the interior is still in bits. I'm putting in new carpet and the dash is still out of the car.
Is the BEM part of the workshop manual or a different thing? I have an actual workshop manual and I know of one online also. Could you point me to the BEM online if it is not the workshop manual?
Ah yes, family life takes top priority! Thanks for the history on your FD. Although it wasn't driven much, one could say that being stuffed in a bard for 9yrs would be a hard life. Especially when mice want to call it home!
You seem lucky in that your car had no electrical issues after mice called your FD home.
When you removed the instrument cluster to repair the mouse damage, did the odometer still display the mileage? If you don't remember then that's ok. Given my observations in Post #2 above, if you apply power now then it may or may not display the mileage. You don't have to do that...I'm only pointing out that bad components on the speedo board may not allow it to work properly. Thank you for the feedback on the odo backlight. This normally works even when the odo is blank. If it was out then that means another sub-system in the speedo board may be bad.
I didn't see any other evidence of solder being removed or replaced elsewhere on the board so that crud around one eyelet (the red box) was probably old flux. If you use a q-tip and rubbing alcohol then it should come off. I would recommend cleaning that flux off because it is normally corrosive. When you look at some of my speedo posts then you would notice the same stuff. Again, a little rubbing alcohol and a q-tip would remove that spec of crud.
My goal wasn't to alarm you that someone made a sloppy repair to the speedo. It was only to draw attention to a suspect spot.
The BEM is not part of the FSM. The FSM is the short but thick blue bible seen in your photos. The BEM can be downloaded from this website: List of RX-7 FSMs. Look for "1994 Body Electrical Troubleshooting, 19.6MB".
Where in MI are you? I have a good buddy who lives in the Lansing area.
Honestly, I was amazed when I put the battery in last fall and turned on the accessories and everything worked/nothing shorted out and killed the system. When I pulled the carpet I did find that the heat sensor wires had been chewed through, but so far that is all. Just a LOT of mouse nesting, poo, and smell. Thankfully now that all the nest is out and the carpet is gone things are heading the right way.
When the odometer came out the odometer did display the mileage. This is from last fall when it was fresh out of the garage.
I tried to take closer photos of the caps, but focusing that close is tough. closer look, and hopefully level with the tops of C16 and C17. They both look and feel flat on top to me. An attempt to get level photos of C2 and C4. Again, the both look and feel flat to me. An attempt to get level photos of C2 and C4. Again, the both look and feel flat to me. An attempt to get level photos of C2 and C4. Again, the both look and feel flat to me. Cleaned off the solder rosin around the one pin on the speedo.
Thanks for the link to the BEM. It's amazing how good google is for so many things, but not so much for finding stuff on "3rd gen RX7" or "FD RX7".
I'm in Grand Rapids, MI. Just about an hour from Lansing.
Also, as I said, I work in a place with a guy where we have nice electronics equipement, so I (or my buddy for precision work) can solder and de-solder well.
Can we check out the speedo by applying power and a signal from a function generator?
1. Who can tell me what this connector goes to? blue connector in the shift harness
2. Where does this plug in? Green connector near the gauge cluster
3. How do you seat the connector (two pieces of orange and blue) for the passenger airbag?
Regarless, I tried to start the car.
Results: car starts but runs very poorly. Also other then the lights, it seems that none of the gauges are working. Maybe related to the unplugged connectors?
That blue connector is not used for USDM models. That belongs to the Headlight Cleaner Switch (Blue). That plugs into the middle dummy socket on the center console. Refer to BEM, Section D-3, Pg D3-5.
Regarding the Air Bag connectors, refer to the BEM, Section S, Pg S-3. It discusses the Double Lock connectors.
The Green Connector should be the Headlight Retractor Switch. Refer to the BEM, Section E, Pg E-7 & E-8. It should be connector E1-01 but does specify a color for the connector. To be certain, refer to the wire color codes on Pg E-7 then compare them to the actual connector.
I recommend becoming very familiar with the BEM since your interior is being rebuilt. The interior sketches in the BEM really help ID connectors, wire harnesses, and other components. My memory is good but when a project sits for a long time, I have a hard time remembering how all the important stuff go back together! LOL
Thanks for pointing me to the page in the BEM for the dobule lock air bag connector. I had no issues with the one under the steering wheel, but the passenger one really had me.
Turns out the green connector was not really in the right place. That is the JB-02 connector for the left hand Joint Box. Fingers crossed that helps. Didn't get a chance to turn it over again after finding that.
I agree with becoming familiar with the BEM, but lordy, that is a long book.
Lastly, the results may be suspect, but I did get the back of the car up to check the VSS signals in the cluster harness (granted the JB-02 was unplugged so, as I said the results are suspect). I was using a DMM but I did not see any change in voltage while turning the rear wheel.
Well, after plugging in the green to the correct place the car still runs poorly and if you press on the gas it will not accelerate much. Hard to tell as the tach also is now not working.
in addition to the mystery plug near the ECU, I found three other single wires that are simply broken. Mystery red wire from next to/behind the driver side joint box. Black wire that is a ground. Another broken ground wire. Black single spade connector near the ECU and cabin blower fan with a black wire with yellow stripe.
Regarless, look like I'm taking the dash back out to figure this out.
Do you know how much needs to be connected to successfully run? I'm thinking that in addition to the speedo issue, I know have either a missing connection or a bad ground.
I'm glad to hear the BEM is helping you ID some of the electrical connectors. If I did not already address the capacitors on your speedo board then here's my observation - they look fine from the angles you captured. I would also recommend that you take a close look at capacitor C3 for its legs to look wet. That would be acid leaking from it. C3 is a high failure item as these boards age. If it looks ok then you have nothing to worry about. Overall, I believe your speedo will be ok because it has not been electrically cycled for so long.
Did you remember to connect the flex print cable to CON1 on the Speedo when you installed the instrument cluster for this test run? It is VERY easy to forget it...I do it frequently.
The 2 disconnected ground wires must go to an aftermarket component - was there an aftermarket alarm installed in the car? Can you find where that red wire goes? I wouldn't rip open the wire harness though. The red wire has a clean cut. Maybe someone went in with a pair of diag. pliers (aka dykes - no slander here, btw)? If you find what the red wire taps into then please let us know.
As for the car running like crap, wasn't there a wire broken in the engine bay? The water thermosensor wire, maybe? Was it repaired? If it's disconnected then the car may idle poorly. Could you also suspect a vacuum leak? This advise helped another member identify a bad water thermoswitch connection:
Refer to the FSM, Section F, around pg F-178. You are looking for the Quick Diagnosis Chart. When there, look for the item "Cranks normally but hard to start" then "When engine cold". This chart will steer you in the right direction of possible parts to inspect.
BTW, thanks for sharing the info about your buddy! Grand Rapids...cool! Never been there before.
I did remember to connect the flex board to the speedo, but I can see how that is easy to forget.
I must say that I'm seriously bumming considering that the car ran very well before taking it all apart. It was my biggest fear and it was realized. Big bummer.
That was my suspicion on the ground wires as well, but it is crazy how much someone may have done between fall of '93 and fall of '98. But then again, anything is possible. As it turn out, I didn't have a front strut tower bar when I bought it. Was this standard?
I haven't pulled the joint box to see where that red wire may come from. I'm trying to not be obsessive out this as I would like to remain married too.
I didn't have a broken wire in the engine, but I did replace the PS pump. Maybe I pinched something? sigh, more stuff to take back apart.
GR is "Beer City USA" so if you are into craft beer this is a fantastic place. I usually have 2 to 3 of my own homebrewed beers on tap at any time.
BTW, I really appreciate you being active and helpful. While the 7 community is great and active, it is not a common vehicle and keeping these on the road is going to have to be a community effort going forward. It is just nice to have someone to bounce ideas off of.
I had an '85 GSL and had to give it up because I was in college and couldn't do it justice. I regret that to this day. It was like a go-kart, but I didn't have the skills or motivation at the time to do what was needed to keep it going.
I love my FD and plan to keep it, but I would love to have another 1st gen.
For what its worth, that black spade connector looks like the one that's on the fan recall harness. Mine doesn't plug into anything either, and it seems to work fine.
Not sure on your extra wires. Definitely looks like someone had something aftermarket hooked up at some point. Those ground wires definitely don't look stock to me. I'd guess the red wire goes to +12v somehow, and was being split to two devices that used those ground wires. I'd just remove them, I can't imagine they are causing any of your issues. (I'd trace that red one back though, and make sure they sever the OEM harness or something stupid like that.)
I'm sure you'd have noticed this already, but that red wire doesn't go to a fuse tap inside the box right? I use one of those to power my dash cam.
Alternatively if its a custom wire and they ran it where I think they would into the engine bay, you should be able to find it somewhere around the cruise control/brake booster coming out of the firewall.
I see what looks like some other wires going to those ground points they added to the pedals. I'd see if you can tell where those go as well.
For what its worth, my car came with a dead speedometer (odometer didn't count, but did show a number), and the tachometer would work on and off.
I was never able to determine the fault on that odometer board. Fortunately my car came with an extra cluster, that ironically had a working speedo and a broken tachometer. I took the working tachometer and speedometer and put them on the same cluster, replaced all the bulbs (PO had disabled the check engine light ). That solved most of my problems. The tachometer started behaving a lot better when paired with the working odometer.
I believe it was caused by a bad capacitor, but I couldn't track it down to anything obvious, and I moved onto other things since I had the spare parts already. I think I have seen some people on here send their clusters to a company to have the suspect components all replaced, but I can't remember any details besides that.
If you are still using the stock ECU, I'd definitely check for codes just to make sure the ECU doesn't have anything helpful to say (and hopefully your CEL actually works)
In case it's any consolation, while my car did not have a literal rats nest inside of it, the rear subframe was packed full of brown widows. Unwanted passengers are just part of the RX7 experience I guess.
Don't get wrapped around the axle too much about the issues you are having right now. Remember, you stripped out the interior and now building it back up. You cannot remember to do everything so you should expect to see problems. The important thing to remember is that you learn from the experience. Dealing with electrical gremlins can be overwhelming. However, take a logical approach and tackle one electrical problem at a time. Electrical troubleshooting is not a sprint, it's a marathon!
You are welcome and thanks for the compliment. I'm no spring chicken here and I was once in your position. So I'm glad to lend a hand!
Good to hear the flex print was connected! But did you verify it was connected? BTW, you don't have to install the cluster on the hood and then install the hood on the dash. When troubleshooting a problem with the cluster, remove the hood then separate the cluster from it. You can rest the cluster on top of the steering column. Just don't drive with it like that.
IMO, I wouldn't pull the fuse box (joint box) but wouldn't mind looking around and behind it. You may discover where that red wire goes! Move it around and see what you find. If the dash is already out then might as well!
Your question about the strut tower brace - the R models (R1 & R2) came with the strut tower brace and stiffer suspension. Owners could install the brace as an option (if I remember correctly) or they installed an aftermarket one. For example, my FD is a touring but I installed a cusco aluminum front strut bar.
What was your setup when testing the VSS signal? Could you walk me through your process? What were your meter settings? Did you reverse the meter leads to verify any difference in polarity?
I have a tip when connecting those hard plastic connectors to the instrument cluster flex print: slightly bend out the each flex print pedal. Be careful not to put a crease in them! They should stick out towards the center of each socket. This will help mate the flex print soft copper pins to the the hard plastic plug's pins. If the flex print is pressed up along the inside wall of the socket then it may not make a proper electrical connection. Try that and see if your tach and other cluster components comes back to life.
As for the SA22/FB, I owned 2 of them. My 1st car was a base 85 RX-7 with the 12A motor and carburetor. I then moved up to an FC and eventually added my FD to the stable. At one point, I owned all 3 generations at once. I got the 2nd FB (GLS-SE) because I felt nostalgic for it and I thought it handled better than my FC. From my experience, it was fun driving an FB again but I didn't enjoy it as much as I remembered. You could say it was those rose colored glasses affected my memory. The FD is a far superior car to the earlier generations in many aspects. However, it is an overly complex machine that requires vigilance and constant attention!
I decided to pull the dash back out and take the harness off the dash. I figured that should make it easier to plug things in and check the connections. There are 3 ground connections from the harness to the metal of the dash. How important are these? should I run a wire from them to the metal were the dash meets the body? I figure that is probably a safe call.
The latest data point: I plugged the radio in and attempted to turn it on. Symptoms: speakers make a periodic poping sound, no sound on the radio, and the bulb for the dimmer was slowly pulsing.
One other point that I should probably share. When I was replacing the PS pump I spilled some (a spray paint cap full) of the fluid straight down. Probably hit connectors and such on the way down, possibly including the plugs on the front rotor.
Don't know if it is bad form to link to a different forum, but here goes:
I found this https://www.norotors.com/index.php?topic=2468.0 and for the love of me I cannot find G-12 (instrument harness) in the FSM nor the BEM. Everything seems to stop at G11. Following the somewhat logical approach to grouping the connectors by the starting letter, it would seem like G-12 would be part of the cabin heating/cooling system.
I'm trying to map where each pin on each connector goes so that I can ring them out on my harness.
My dash sub-frame is also pretty corroded at the points where it mounts to the body. I'm going to hit them with the wire brush to make sure a better ground is made to the rest of the car. I'm also going to brush up the grounding points on the sub-frame where the harness makes a ground connection.
I've done enough electrical troubleshooting in my day to know that with a DC system the most likely issue is a bad ground.
I don't think that small amount of steering fluid would cause signifigant damage to the wiring. It is corrosive and its always better to clean up any spills, but you'd have to be pretty unlucky.
Is it the stock radio/speakers? Bose or non bose? I don't think I saw that information on this thread. Its hard to offer an opinion without knowing.
There are a few grounds from the dash harness to the crash bar, and then the crash bar grounds to the chassis where you bolt/unbolt it to remove it from the car. I'd make sure all of those have a good clean contact. It shouldn't ever hurt to add additional grounding, but I'm not sure its the cause of any of your headaches.
Can't help with the pin diagram off the top of my head. If I can find it I will share it here.
Interesting. I have the bose system, but my car never had a working bose radio/head unit.
Generally speakers that pop on a 100% stock system randomly are due to a bad amp, or something that has broken inside the radio itself.
If it's popping proportional to volume or sound level while something is playing, then it might be a blown speaker. It could still be the amps or radio though.
My RX8 occasionally will make some very faint popping/interference noises that come and go with engine RPM, but I'm assuming you are testing just on battery power since you have the interior pulled apart.
I'm somewhat suspicious its the radio though, since you said you didn't get any music. If you have the antennas plugged in, you should definitely have heard something.
We try to keep links from other forums down to a minimum. It does help us understand your train of thought though. There may be a similar thread in our forum. I would suggest using the advanced search feature and look for harness connector or something to that effect.
Regarding G-12, are you looking for the ground point connections or the Heater/AC connectors? There is a difference!
Ground points are identified in the WDM (wiring diagram manual) section of the FSM, Section Y, Pg Z-18. Ground points are normally associated with the Joint Connectors (JC-x), such as JC-01, JC-02, JC-08, JC-09, JC-10, JC-12 and JC-13. Ground points are referenced as a "circled number" because they are typically bolted to the chassis.
The Heater/AC section is identified in the WDM, Section G, Pg Z-68 to Z-70. These connectors are identified by G-series connectors, such as G-01 thru G-11.
In either case, below each schematic is a representation of each connector. A lot of information is presented. For example, look at WDM, Diagram Ga, Pg Z-68. Specifically, Connector G-01. It is labeled as the Heater Control Unit (aka Fan Switch). The (I) (as in "i") means that is is part of the Instrument Cluster Wire Harness. Furthermore, it shows you the pinout of this 6-pin connector.
At the beginning of the WDM section, there is an information page (it has no number) that lists the wire color code. Use this list in conjunction with each schematic to associate each wire to its connector. Typically, the same color wire would be used between system components.
Back to our example connector, G-01, let's look at the 3rd pin labeled "L/W". That is a Blue wire with White stripe. Now look at the schematic and locate the L/W wire on G-01. This wire runs between 2 wire harnesses, the Instrument Cluster harness and the Air Con harness. The L/W wire goes thru Connector X-25 then to G-05, The Blower Motor and (Blower motor) Resistor network.
When you take resistance measurements along this wire, you should verify it at 3 points - from the fan speed switch L/W pin to Resistor network L/W pin, and to Blower Motor L/W pin.
Finally, the adjacent page of each wiring diagram normally displays component locations of that system. These manuals are small which makes it difficult to locate component too close together. For example, the bunch of connectors by the fuse box or ECU! If you are fortunate enough to have a full-sized FSM+WDM then locating these components are easier because the paper is sized from 8.5x11" sheets.
Like you did in an earlier post, take a photo of the connector and its surroundings to help identify it and its location. If you can provide the wire colors of the suspect connector then that would also help us help you!
Also getting back to your VSS problem, have you removed it from the transmission to test it yet?
P.S. This thread was originally in the New Member Technical area of the forum. It was moved because the OP exceeds the 10-post restriction and I believe he could gain additional insight from our FD members who typically hang out here. Feel free to say hello to bake3310, aka Dave, and offer any pearls of wisdom that may help!
Last edited by Gen2n3; 09-01-19 at 08:32 PM.
Reason: Added Post Script.
Hi George,
Sorry about the link to the other site. Sometimes when you are using the ol' google you find yourself somewhere else and the information is interesting.
The reason I ended up there is that I'm trying to figure out why things got worse when the instrument harness went back into the car. As I said before, before taking out the dash, trim, carpet, etc. the car was running quite well. So I figured I either missed putting something back together or there is a problem in the harness. I wanted to figure out what each plug on the harness did, and where the wires on each plug go so that I could check them for continuity.
Here is the harness on my table. The unknown connector is the blue one on the top (not the one next to the orange one). Here is the location in the car where the connector plugs in on the passenger side.
As for the VSS, I have not pulled it to check yet. I am currently more interested in solving the running issue first. But to answer your questions earlier about how I originally tested the VSS on the instrument harness. I had my Fluke on the two terminals of the harness. I had both rear wheels off the ground and the car in neutral. I did switch the meter so the leads were on both just in case the voltage only showed up in one direction.
I figure once I put the harness back in the car, I can do that check again before pulling the VSS.
Have you pulled the VSS ever? Any advice?
Somewhat unrelated. I found this "mess" on the wiring going from the harness to the joint box on the driver's side. I'm not sure if the wire was damaged and repaired like this or if someone tried to tap off this wire with this.
It's the yellow wire with orange stripes. It is on terminal H on the JB-02 connector which seems to go to connector C1-01 terminal 2I.
08-27-19, 08:54 PM
). That solved most of my problems. The tachometer started behaving a lot better when paired with the working odometer.
