RPM & Speedo stopped working
 

Hi all,

Today my RPM & Speedo on my cluster just stopped working. This did happen a little while ago and after I took out the cluster and fiddled with the wiring, it managed to start working but today there was no such luck. I have another cluster laying around and did connect it up and the same issue is persisting so it's no the cluster.

Any idea on what I can look at to try diagnose the problem?

When these clusters go bad, the speedo and tach can go out at the same time, everything on this cluster (in a sense) is controlled by the speedo board. Is this second cluster known to be guaranteed working, and recently at that? If you cant personally vouch for the extra cluster working very recently, then it's entirely possible you have two clusters on your hands needing repair. Check the guides for repairing them if you are confident with de soldering and re soldering, or send it out. Circuit Board medics were okay in the sense that they do a lot of fd cluster repairs, so they know what to look for. Downside is they took longer than I feel they should have with my cluster, though it did have issues aside from the normal capacitor issue, they still quote a certain time frame.

I could be wrong, but I'm still going to say I think its the speedo board issues that is well known on both clusters.

Thanks for your feedback SwappedNA. To be honest, the cluster itself I cannot vouch for but found it quite coincidental that the exact same issue was occurring. I'll try get a hold of a good working cluster and test.

Forgot to ask,

Do the warning lights and the Fuel/Oil pres/Coolant temp gauges work?

Yes everything else works, just the RPM & SPEEDO have stopped.

I think you will find the culprit is the cluster board needing the usual repairs. Unless you can get a known good cluster to test with, which, I'm pretty sure would confirm what I'm thinking it is anyway. I'd pull it and start the repairs, or send it to circuit board medics. I think its like 220? Mine had some faulty traces they fixed as well.

I was completely unaware of cluster medics, excited to send my cluster out asap.

They do good work in the end, however, if you daily your car, plan for extra downtime. I paid to have my cluster shipped next day air early am & dropped it off at the FedEx hub at the airport nearby just to be sure. It got there at nine am the next day. They didn't even touch it until the day after that. Then I get a call saying their normal repairs didn't work, and they were escalating it to other technicians and I'd hear back in two days (I want to say.)

I tried to call for an update, and the person that answered didn't seem to know much, and they obviously weren't the tech working on it, and It didn't seem like they were keen to go find out any information, either. They finally called me at the end of the two days and said there were some bad traces on the board they had to repair and it was finished. This was a Friday, and I paid for next day air there and back, because I needed the car running. So I asked them whats going to happen with returning the cluster. I had to pay an extra 30.00 on top of what I already paid for shipping to have Saturday delivery.

After all was said and done, the cluster was back, and is working great so far. I would consider my experience the exception, most likely. I've only had my one cluster repaired there, so I can't say if it's the norm for them, but I doubt it. My chief complaints were they advertise up front a one day turnaround. I realize they didn't have to get to it that day, but when they offer next day shipping early am, I figured that they would. Communication was eh, never got to speak to the techs doing the repairs. Which, understandably, that would slow them down, but when I worked as a tech at my job, I still called every client. The cluster had a surprise, but they still advertise one day. I'm assuming they just tried their blanket repair and when it didn't work they started looking deeper, rather than doing a full diag ahead of time. I felt like they could have at least met me halfway with not making me pay the extra for Saturday delivery, considering it already took longer than what was stated up front.

If you aren't in a rush, or don't have a cluster with a unique situation like mine, it probably will go smoothly, but plan for downtime regardless.

rexhvn,

Did you say that you swapped in another instrument cluster and the tach + speedo is still dead?

If so, then you may want to verify the flex print is making positive contact with the C1-01 connectors. Clean them with a rubber eraser, then apply rubbing alcohol to them. Afterwards, bend them towards the center of each hole. Be careful not to kink or crease them! You just want to roll them towards the center. This will ensure proper contact with the C1-01 connectors. Additionally, visually inspect the flex print for any potential damage.

Furthermore, make sure the flex print cable is connected to CON1 (the flat connector in the upper left corner that is protected by the black plastic shroud. If that is disconnected or damaged then you will not have a functioning tach or speedo.

I am currently looking into circuit board medics. My tach went out recently and odometer as well. There also looks like there is a burn mark on the odometer screen? I am trying to decide if I should follow some of the DIY videos and attempt to do the soldering myself or just use circuit board medics... I have read that many people that try and even succeed with the DYI --- it ends up dying again down the road.

circuit board medics apparently can repair it while keeping mileage. I am at 48k miles and def want to keep that! Lol

I am not seeing many reviews here on the forums for circuit board medics though

Thoughts?

Thanks bros
-Alex

See my post above. Unless you are skilled at soldering, I wouldn't recommend it. If you are skilled at soldering, You will likely find it to be a pain due to the caps being soldered to both sides of the pcb, at least that was my experience, that's why I just sent it off.

Roger that bro. That is what I am leaning towards..

Thanks!

Alex,

If your LCD screen is boogered up then they may have a problem replacing it. The only way to source a new LCD screen is to cannibalize it from another speedo. Have you removed and inspected your speedo board yet? Care to show us that burn mark on your LCD display?

Sure man. Sorry I’m new to the forums. So still learning - hopefully these uploads are not too big.

odo came back on. Then when I came back from inside the store and it was out again - and so was my tac and speedo - then after another start up speedo and tac were on but odo wasn’t :dunno:

I think maybe it’s not a “burn” because when odo displays I can in fact see the numbers.

i have not removed and inspected the board yet.

Thanks Guys. Love the FD and beginning the journey. Just got her not long ago and finished doing full fluid flush, coils rims and tires. Going to do hawk pads, StopTech rotors and steel braided lines this weekend (and brake fluid flush)

Now it’s off to the smaller things like this


https://cimg5.ibsrv.net/gimg/www.rx7...6add807a7.jpeg
https://cimg6.ibsrv.net/gimg/www.rx7...0ce8ae998.jpeg
https://cimg7.ibsrv.net/gimg/www.rx7...a4adc7429.jpeg

https://cimg3.ibsrv.net/gimg/www.rx7...00cc88698.jpeg
https://cimg5.ibsrv.net/gimg/www.rx7...ccacd5b04.jpeg

Alex,

Thanks for sharing some photos of your clean FD!

You must be referring to the circular spot on your LCD display. Right? Unfortunately, I don't know what that could be. Maybe the polarized film is goobered on the LCD screen? I've seen worse though.

Since your odo and speedo are intermittently working, I would highly recommend that you remove the cluster and inspect the speedo board. I curate a couple threads associated with this topic. While in there, take some photos of the board and post. I would also recommend applying isopropyl alcohol on a cotton swap to any leaky caps (if any) on the board. This will at least neutralize the acidic effects of the electrolyte chewing away at the solder runs and other leads. Please refer to those threads: the just found out how to fix an FD odometer and my FD Speedometer threads. They are an easy find when searching the forum.

Out of curiosity, where in NC are you?

Thanks brother!

Roger that George!! Will do!

I am about 30 minutes south of Raleigh!

-Alex

Alex,

Copy, south of Raleigh.

If you have any questions about the speedo board then don't hesitate to reach out to me or post in those threads. I may be able to advise on the problem with pics of the board.

Solid copy brother!

Will def let you know as soon as I crack it open. May be a week from now though. Possibly this weekend.

sent you a friend request

I just checked “just found out how to fix an FD odometer” —- I actually had this one saved! Lol

will def touch basis with you brother. Might not be necessary to spend hundreds of dollars - Thank you again.

What ecu are you running?

Copy all. Friend request approved.

I don't want to be all doom and gloom but the sooner you can neutralize that acid from any leaking capacitors then the less damage it will do to your circuit board. Keep in mind the speedo sits vertically so any leaky cap will ooze its acid and run down the length of the board.

Just remember to be careful when removing the cluster hood. Your 93 plastics have a greater tendency to crack.

Word. Roger that George. I’m excited to get in there.
thanks for the warm welcome man. I’m loving these forums. Getting hooked!

I will snap some pictures ASAP. Should I post them in here or in your other forum posts on the topic?

-Alex

https://cimg3.ibsrv.net/gimg/www.rx7...2884ca4d7.jpeg

Alex,

Glad to lend a hand! Make sure that the ground wires to the ECU are properly connected, in case they came loose or if you did any digging around the engine bay or ecu. You can post pics and discuss the speedo here: Troubleshooting the FD Speedometer-Odometer We can get into the weeds there.

How does that sound?

Sounds great man. So it may just be a ground wire?! Okay yes .. I’m still learning haha

I got the car from my tuner for my FC, so trusted source, but I want to learn my own and not keep buggin him.

So milage wouldn’t affect how much corrosion is on the circuit board would there? Being that it has less than 50k miles - it is still a 93... and old = corrosion even with low miles, correct?

Alex,

Did you do any digging around the ECU or engine bay recently?

Corrosion is a separate concern. Mileage will not affect the function of the speedo board. The number of power cycles, the age of the electronic components, and exposure to heat-cold cycles have an impact on the speedo board. Chiefly, old electrolytic capacitors have a tendency to leak their fluid. It is a "silent" killer because one day it will work then the next day it will not.

The intermittent problem you are currently experiencing with your speedo, tach, and odo may also point to poor ground connections. Especially with an aftermarket ECU like the tried-and-true PowerFC. Just double check your ground wires. If a ground wire touches the chassis (which it should) then make sure it touches bare metal. Touching a ground cable to a painted surface will not conduct electricity, or do it very poorly. If the ground wire is connected to one of many OEM ground points then verify that a connection is made.