When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
So I put the harness back in and attached some ground wires from the harness to the dash mounting points.
It seems to be running better, but still is surging under idle. Runs rough, but will accelerate with the accelerator. Lots of smoke, which has been common when I start it when it has sat for a while, but usually it clears up. This hasn't. https://photos.app.goo.gl/sMFa1neNBPjaQx846
Maybe others can see the movie on this link. The video is beyond the limit.
With the shaking that I feel in the cabin, it seems like maybe only one rotor is firing?
Unless someone has a great idea, I'm just going to work through the FSM troubleshooting...hoping that there isn't rotor damage.
Also, the tach now rising up to about 750 when the key is turned to ACC.
Oh wow. That does looks like a really bad splice job, since there is still a nub attached to it.
I'd personally redo that splice. Even if you cannot solder, I think a good crimp connector would still be better than that. If you don't feel comfortable with either option, I'd definitely insulate the existing joint with some electrical tape or something. Any time a bear wire can accidentally ground out from being exposed, really weird stuff can happen.
Regarding that plug, I do see where I took a similar picture to yours when I pulled my dash and hvac system off, but unfortunately I didn't make any special notes about it, or take a picture of what it actually plugs into (I marked all the connector pairs before I unplugged them, so I knew where they went, unfortunately because of that I didn't get pictures of each one)
I might stick my head in the passenger well and see if I can find it with a mirror, but I think that one might tuck inside the dash when you put it back in.
From memory, I think it just plugs into the dash/dash bar harness.
Wish I could tell you more. Here are some threads that might help you out though.
Seems like you are on the same track. The connector labelled G-12 on one of those annotated harness threads also looks to be the connector you are looking for. Interesting enough, I don't think my harness or the one in that thread has the orange connector like yours (the connector is there, but it is not orange)
It seems I have figured out the rough engine issue.
When I took out the PS pump I took off the air inlet (the black plastic bit that attaches to the throttle body). In doing that I must have knocked the hose of the boost sensor. Re-attached the tube and the idle is stable.
Looking through the troubleshooting guide I didn't see the boost gauge listed as a potential thing to look at. Add it to the list of things.
Now, I still have some oddities on the gauge cluster.
The tach immediately jumps up to 750 as soon as the key is turned to ACC and maintains that offset once it is running. The odometer backlight seems to not be working. Can't say about the speedo as the car is not back together on the inside.
Here is the location in the car where the connector plugs in on the passenger side.
Look at that fresh new carpet!
Originally Posted by bake3310
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.
IMO, I would cut off that nub of wire which appears to be severed from the splice point. That is definitely NOT an OEM splice. I would also recommend not messing with that splice point unless absolutely necessary. You may use a product called liquid electrical tape. It is made by Permatex and could be found in Home Depot, Walmart, or auto parts store. Here is a link to the product description: Liquid Electrical Tape link. This liquid electrical tape has an applicator brush to apply a sealant across an electrical splice. That may be a better solution rather than using normal electrical tape. The liquid stuff forms a better bond than "normal" tape and it will not unravel like "normal" electrical tape.
Before applying liquid tape to that splice, I would suggest an assistant wiggling/flexing (not too hard) that wire around while you measure the resistance of that wire between input and output devices. Have the assistant use rubber gloves to insulate themselves because they may impart a change in the measurement. If it reads a short (anything less than 2 ohms) during this flex test then I would call it good and seal it. If it wildly fluctuates then I would repair it first, verify repair 2nd, then 3rd - seal it.
If that wire goes to Pin 2I (eye) on C1-01 then it is only a Yellow wire, according to the WDM. That wire originates at CPU #1 (in the Body CPU) at Connector JB-09, Pin A. After the yellow wire leaves Pin A, it branches off to the Electrical Load Control Unit (see Diagram B-1b) and the Rear Window Defroster Relay (see Diagram I-1). The wire at C1-01 Pin 2I is an output to the Instrument Cluster and it drives the Rear Defrost Light.
I don't remember what those small orange square blotches on the yellow wire mean. That may be an answer found in the colorized version of the WDM. For example, the Emissions Harness may be identified by a specific color. I just don't know! You can also see similar color markings along other wires in that photo. When a wire has a stripe then it will run along the length of the wire and will typically be much thinner than the main wire color. This would reduce any confusion when identifying wire stripes such as a red wire with white stripe and a white wire with a red stripe. Wasn't there an episode of Archer that exploited a similar situation?
I wish I could offer more advice when testing the VSS when removed from the transmission. I have not done such a test. Before removing the device from the transmission, test it again after you know all connectors are attached.
Verify the ground pin, Pin 1E on C1-01 is properly connected to chassis ground at Ground Point 3. This ground wire goes thru X-18, X-17, X-19 (to Connector B1-06, Fuel Gauge Sender Unit), X-14, and X-05 before it hits Ground Point 3.
This may help ground your tach. Also make sure all 3 screws are secured to the rear of your tach and they contact the flex print eyelets.
It seems I have figured out the rough engine issue.
When I took out the PS pump I took off the air inlet (the black plastic bit that attaches to the throttle body). In doing that I must have knocked the hose of the boost sensor. Re-attached the tube and the idle is stable.
Looking through the troubleshooting guide I didn't see the boost gauge listed as a potential thing to look at. Add it to the list of things.
That is good news! Good to hear you found the culprit of the rough idle. Did the troubleshooting guide help?
USDM cars do not have a factory boost gauge. Members sometimes install a JDM cluster, usually post 95+ clusters, that have a boost gauge instead of an oil pressure gauge. The JDM cluster has to be modified in order to work on USDM cars by means of an extra ground and wires added to the flex print.
Oh wow. That does looks like a really bad splice job, since there is still a nub attached to it.
I'd personally redo that splice. Even if you cannot solder, I think a good crimp connector would still be better than that. If you don't feel comfortable with either option, I'd definitely insulate the existing joint with some electrical tape or something. Any time a bear wire can accidentally ground out from being exposed, really weird stuff can happen.
Regarding that plug, I do see where I took a similar picture to yours when I pulled my dash and hvac system off, but unfortunately I didn't make any special notes about it, or take a picture of what it actually plugs into (I marked all the connector pairs before I unplugged them, so I knew where they went, unfortunately because of that I didn't get pictures of each one)
I might stick my head in the passenger well and see if I can find it with a mirror, but I think that one might tuck inside the dash when you put it back in.
From memory, I think it just plugs into the dash/dash bar harness.
Wish I could tell you more. Here are some threads that might help you out though.
Seems like you are on the same track. The connector labelled G-12 on one of those annotated harness threads also looks to be the connector you are looking for. Interesting enough, I don't think my harness or the one in that thread has the orange connector like yours (the connector is there, but it is not orange)
Thanks for sharing those links! I knew it looked familiar when I read the NoPistons link. And it was posted by the same username too!
No problem George. Those are on a list of threads I visit pretty frequently when my own pictures/notes fail me on something (along with the thread where the guy pictures each step of total engine bay disassembly)
I'm curious why you would leave that splice as is? It doesn't seem like a great solder connection. Generally when I find substandard custom electrical work, I try to take the time to clean it up. A lot easier to shore up now with the dash out, then if it starts to do something funny later on.
A proper sized crimp connector and a good (ratcheting) crimp tool would make easy/quick work of it. I'd also use some shrink tubing over the crimp for safe measure/insulation. Maybe that's just my OCD talking though.
No worries, I'll be happy to explain. If the splice doesn't look pretty but is electrically and mechanically sound then it's best not to mess with it. Just seal it to prevent any shorts or wire chafing.
In order to properly clean up the splice, you would have to cut away that mess then splice in additional wire to fill in the gap. Additionally, adding wire adds 2 splice points. That creates 2 potential failure points. Furthermore, simply cutting out that segment then using a butt-splice will shorten that one wire and put undue stress on it while driving. Again, that would create a potential failure point.
We also don't know how much space Dave has to work with this repair nor know his experience with splicing wires in unusual places or positions.
Normally, I agree with your procedures. A butt-splice or even soldering them (as was this case) is an acceptable repair. The use of heat shrink tube is an excellent idea, I use it when possible.
I have some minor experience with the liquid tape repair. I found a few splice points along wires in my Vert. They fed an aftermarket alarm system that I removed years ago. Well, the OEM wire had a segment of insulation missing then the wire "tap" was wrapped around this exposed wire. It was a poor attempt at a lineman's splice, aka Western Union splice. Some splices were very close to the Body CPU & fuse box. I was not going to contort myself in the driver footwell in an attempt to properly repair those exposed wires. Instead, that liquid electrical tape stuff came in handy! I applied a little dab then worked it around the wire body. After it cured, the liquid tape sealed that exposed wire and have not had any issues since.
Ah, that's fair enough. It looked like he has some slack still, but it could just be the angle of the picture. I guess if Dave can verify the resistance/continuity stays consistent it should be fine. I've had mixed luck with that when they are over-soldered like this.
I've had to make a lot of wiring repairs in contorted spaces on my RX7 for one reason or another, so I guess I'm used to the pain. I definitely remember it was pretty difficult without the proper tools (and even with them, sometimes).
I'll have to keep the liquid tape in mind. there are a lot of times that would have been really useful.
I do like the new carpet, but I'm going to have to clean it before reinstalling everything as I've made it a bit dirty with all this extra work I've been doing in there.
I need to get back to the gauges now that the engine issue is resolved.
There is some corrosion on some of the screws that go into the tach and speedo, so I'll either replace or clean those. Probably not doing me any electrical favors there.
Thanks for the additional advice on grounds. I'll take a look at those too.
Looks like a busy home life week this time around so I'll let you know the results when I get a chance to get back to it.
Thanks.
Originally Posted by Gen2n3
Dave,
Verify the ground pin, Pin 1E on C1-01 is properly connected to chassis ground at Ground Point 3. This ground wire goes thru X-18, X-17, X-19 (to Connector B1-06, Fuel Gauge Sender Unit), X-14, and X-05 before it hits Ground Point 3.
This may help ground your tach. Also make sure all 3 screws are secured to the rear of your tach and they contact the flex print eyelets.
Also, I got under the car to see if I could get the VSS out easily (nope) or open the connector from the VSS (also nope). The exhaust and a brace are in the way of getting easy assess to the bolt that holds the VSS in. The connector was just suborn as heck.
And you are right,
"M" as in Mancy from the episode "Skytanic".
Blue with a white stripe or white with a blue strip.
Also, I have to go back to the color guide as I forgot that "L" stands from Blue, so that "B" can stand for Black. It all makes sense, but I'm used to "BL" for Blue.
LOL, I get a kick out of that Skytanic episode. "Lana, Jesus! Be careful. The HELIUM!"
Dave,
There really is no need to clean up the tachometer screws. Unless they are a Statue of Liberty green then they will conduct electricity without issue. As an alternative to removing the VSS, you could disconnect either Connector X-14 or X-15 then test the VSS signal there. It will be the Y/R (Yellow/Red) and Y/W (Yellow/White) wires at Connector X-15.
CAUTION: Connector X-14 at the Emissions harness side have wire colors G (Green) and O (Orange) for M/T. For the few that have A/Ts, the wire colors are G/B (Green and Black stripe) and L (Blue).
Looking in the wiring diagram on page Z-42 it looks like ground #3 goes through X-18 (grouped together with 4 other signals (not ground)), then X-17, then splits and one goes through X-19, X-24, and B1-06 (fuel gauge sender unit) while the other goes into X-14 (MT) and finally to point #3.
Again, I think that X-14 is behind the heater core (based on the artist's rendering of the location of X-14 on page Z-41).
In theory, wouldn't all the ground points be at the same potential? Seems like you could also tie pin 1E to pin 4H (page Z-44 Turn RH) and that would tie to ground point #6. Thoughts?
BTW, I strongly disagree with 4 connectors all being called C1-01. Sure, sure, they have different terminal numbers but it just doesn't make sense to me.
Originally Posted by Gen2n3
Dave,
Verify the ground pin, Pin 1E on C1-01 is properly connected to chassis ground at Ground Point 3. This ground wire goes thru X-18, X-17, X-19 (to Connector B1-06, Fuel Gauge Sender Unit), X-14, and X-05 before it hits Ground Point 3.
This may help ground your tach. Also make sure all 3 screws are secured to the rear of your tach and they contact the flex print eyelets.
I understand completely about checking at Connector X-15. BTW, what was your decision on repairing that Yellow wire splice we talked about (post 31, et al)?
You are doing great work! Hang in there and soon enough you will reap what you sew. I know it isn't easy, especially dividing your time between work, family, and car repairs.
I brought the harness into work and we de-soldered the wire that had been spliced into the harness and then soldered it back together with some shrink tube around it.
Any thought on my previous idea regarding connecting 1E to 4H/ ground point #6?
Another idea to make it easier to remove the cluster/hood while troubleshooting and putting a few miles: take out 2 of the 3 spring clips that hold the hood on. Solve the cluster issues and then re-install for a more permanent solution.
Originally Posted by Gen2n3
Dave,
I understand completely about checking at Connector X-15. BTW, what was your decision on repairing that Yellow wire splice we talked about (post 31, et al)?
You are doing great work! Hang in there and soon enough you will reap what you sew. I know it isn't easy, especially dividing your time between work, family, and car repairs.
Normally speaking, ground is ground in an electrical circuit. In electronics (and electricity), a signal travels to ground via the path of least resistance. The gauges use Ground Point 3 because it is also the "shortest" physical route to ground. The instrument cluster uses a few ground points to keep different circuits from interfering with one another. I hope this makes sense: the reason to use multiple grounds is to keep certain circuits isolated from others and to keep a ground point physically close to the desired circuit.
For example, if you remove Ground Point 3, the physical wire that connects to Connector C1-01 Pin 1E then it will also take out the coolant level sensor, oil pressure switch, water thermosensor, and oil level sensor, and fuel level sender. This ground effectively controls all of the gauges while the Ground Point 6 controls other warning lamps (think turn signals, etc...).
Basically, if your instruments fail then you could still control the car - signal lane changes and receive other warning lights, like the brake fluid level/parking brake switch. The brake system ground is on a separate circuit, btw.
I agree that the C1-01 connector should be labeled better. However, Mazda used the same numbering sequence with the ECU. It still is one harness and it plugs into multiple locations on the same device. I normally refer to the C1-01 connectors as C1-01-1 (then add Pin 1E, etc...) but other members may not understand my numbering system. Unless they reference my Flex Print thread where I discuss the use of -1, -2, -3, and -4 Series connectors. Maybe Mazda felt it was redundant to label a connector as C1-01-1 Pin 1E when addressing a specific pin to a connector? I chalk it up to one of the several charms of the FD!
I also find it interesting that the Speedo uses ground from both Ground Points 3 and 6! So make sure that both Ground Points are connected. That may cause the problem with your Tach registering 750rpm when you place the ignition switch to ACC and may read 750rpm above the normal indicated idle RPM. Just food for thought!
IMO, I would recommend keeping the Ground Points separate from Pins 1E and 4H. Ensure Ground Points 3, 6, and 1 are properly attached to the chassis to keep the instrument cluster working properly.
Sounds like you did some great work on repairing that wire! Well done!
P.S. I would keep the instrument hood mount points unaltered as well. The more support given to the structure then the longer it would last. That may sound counter intuitive when you constantly remove and install the hood. But when installed the hood must support the instrument cluster as well. I'm sure you will drive easy but you cannot predict any sudden maneuvers that you may need to make while on the road. Simply put, I don't think the juice is worth the squeeze by removing a couple of brackets just to save time during installation/removal.
Last edited by Gen2n3; 09-04-19 at 01:03 PM.
Reason: Added Post Script
If I understand the book correctly, and that is not yet a given, them page Z-18 shows the ground points and page Z-19 attempts to show where they are in the car.
Ground point #3 appears to be near the solenoid rat's nest and turbos (not very close to the tach, but maybe close to the crankshaft sensor). Ground point #6 is two locations on the instrument panel harness to the crash bar in the dash which is closer to the cluster but farther from the crankshaft sensor.
Page Z-7 seems to show all the harnesses in the car, but I don't see a harness described for the sensor that come off the transmission. You can see them on page Z-43. The nearest ground point would seem to #6, but #3 could be it too based on wire length.
I have another ground question, as I have found the un-labeled ground point on the crash bar which looks like it may go to the radio.
Does this plug into the stock Bose radio? I can't find a socket on the harness, and this drawing sure makes it look like it goes into the radio.
Any guidance on where ground point 3 actually is. I see it on the artists drawing to be near the rat’s nest. Can I see/reach it without removing anything?
09-02-19, 09:14 AM
