My tach hasnt been working properly from the day I got my car and I think its time I fixed it. When the engine is off the tach sits at around 3K, at idle at 4.2K, and when I drive it will function but the rev's indicated are just a few thousand off (lol). Sometimes it will bounce around wildly and get stuck on the back side of the peg as well. Im pretty sure something is loose or maybe the tach just needs to be replaced.

Anyone have this problem before? If so, how did you resolve it?

Thanks,
Chris

 

Anyone out there??? lol

 

I have recently noticed some wild dancing of my tach as well. However, it otherwise functions properly so we do not share totally the same issue. I did a search on the matter last week and found several threads in reference to strange tach happenings. From what I gathered it is quite normal for the some FDs to have tach problems, and that is is not a very difficult fix.

Sorry I dont have any better information, but there are some good threads our there. Good Luck.

 

It could be a problem with cracked solder joints on the back-side of you tach/guage cluster. But the tach gets it signals from the coils, you might want to check your connections first.

 

My PFC is reading the correct rpm's if that helps me eliminate some areas to look at.

 

Friend of mine here in town has similar issue.

-PFC reads correct but the tach doesn't
-Tried 3 different cluster and all does the same thing.
-Tried 2 different PFC and stock ecu, still doesn't work

Anything else?? I'm guessing its the interior wiring harness..

If you find the answer to this, please let me know.

 

Yea, I have been pushing this off knowing its gonna be more of a pain than it looks like... bah

 

This post reminds me of when I first bought my 7. The day I drove it home from the previous owners house, the tach needle started acting up. It would go from bouncing around to being stuck at redline and then show 0 rpms and then go back to working fine and then going crazy again the next minute. The previous owner told me that he had never seen this happen while he owned it. He was cool about it and offered to pay to fix whatever was wrong with it. Being a total newb I didn't want to touch anything myself so I brought it to a rotary shop. I took it to Alamo Rotary (while they still existed) and all Tito could tell me was "I don't know what's wrong with it, I reset your ecu, so it's not that, you might have to buy a new cluster, now give me $45 for labor." No kidding, ya think?! I was bummed out by that and ended up putting it off for months before I decided to do anything about it even though it drove me nuts not having a working tachometer, I just didn't know what to do. I was on the verge of buying an aftermarket tach, but I didn't want to have to resort to that. Then I came across a post about how the "bouncing tach needle" syndrome is usually caused by bad solder connections on the back of the tach. A fellow forum member emailed me the write up he had done on how to re-solder the connections and I decided to do it. I disassembled the tach and took the tach motor and new capacitors to a tv repair shop and for $20 they re-soldered all connections and replace the two capacitors(I wasn't feeling very confident with a soldering iron at the time). The guy told me that one of the old capacitors was bad and that the connections definetly needed to be resoldered. Fixing the tach is the best thing I've done to date since owning the car. Nothing else has such an impact in driving the car then having a perfectly functional tach, it's something I used to take for granted, but then when you go for so long without it and then have it again, you realize how satisfying it is to have that big tach dead center in your guage cluster, giving you that feedback you love to see. It's really quite easy to do, and it's a lot cheaper than buying a new cluster. This has been my experience and I can't guarantee that's whats wrong with your tach, but it's worth trying. PM me if you want the write up (it's saved as a pdf file).

 

I had the same problem and did exactly like he said. I followed the write up and removed the tach and had an electronic repair shop re-solder and replace the caps. and it fixed it. It is very common for the solder joints to crack. Get the write-up and remove it and get it fixed.

 

Here is a copy of the write-up to fix the broken solder joints.
http://www.umsl.edu/~tch9gd/Tach.pdf

 

Thanks guys!!!

Im gonna try this sometime soon and post my results.