Topic: Temp/Oil Gauge and Tach ?

[ta78w72]

I think your coil is OK.  Try replacing the module...keep the old one for a spare/troubling shooting part.  If that doesn't work, yeah, I'd try the coil again.  But you just replaced that, didn't you?  Did you keep the old one?

[mikeb78ta]

Yeah I did replace the coil when I purhased the missing ground strap, But could it have gone bad due to a lack of the secondary ground?  Unfortunately I didn't keep the old coil, but since they are pretty cheap, I may go ahead and replace it and then keep this as you suggested.  If I do that along with  the module.  There isn't anything else we haven't tried...

[brian c]

One other really stupid question....the coil you're using now....is it white wire or yellow wire?

The original one from the factory was white wire for a pontiac 400. Just throwing that out there....

[mikeb78ta]

One other really stupid question....the coil you're using now....is it white wire or yellow wire?

The original one from the factory was white wire for a pontiac 400. Just throwing that out there....

I believe that it is white.  I have the Olds 403 though.  I'll go back and check though.

[brian c]

Here's one other thought....

Try taking the tach physically out of the gauge pod and hooking it up as I mentioned above.

[mikeb78ta]

Already Tried that as well.  No Luck, but thanks anyways...

[mikeb78ta]

Well while I had the car apart today to replace the alternator field wire I figure I would go ahead and replace the module in the distributor and while I was at it run a new "COIL" wire from the distributor through the firewall and finish it at the tach hoping that would solve any doubts about the signal forn the coil at the distributor,  NO LUCK.  I have replaced everything now related to the Tach.  Nothing has worked. I'm completely stumped.  Oh yeah I tried the other 2 Tachs I have Also, Neither of them worked either.

[ta78w72]

It has to be the signal from the coil...has to be.  If your test light didn't dim the signal isn't reaching the tach.  Look for an old guy at work...one that's at least as old as Rick and myself.  Ask them if they have a dwell meter.  They have the tach built into them.  There has to be at least one person that has one.

[mikeb78ta]

I will find out about the dwell meter.  I am considering taking my car out of commission for a month or so anyways.  Long overdue for a much need paintjob and engine rebuild.  I will get to the bottom of this eventually.  Thankfully I will be intown for the next couple of months without any travel for work.  That will give me more time to go through things slowly and find more little Gremlins...  Thanks again for all the advice.  It has definitely paid off...

[BigJer]

Did you ever figure this out? I'm having the same problem with my 81(converted to 73)

[Cbled56]

I don't think it was ever resolved on this site, as I have the same problem too.  I have looked at most of the different threads on this subject, but still can't get mine working.  I might have to just spring for the cash and get a new tach.  I'm starting to think it is a 403 problem.  Most of the ones I have seen are late 78 on that folks have trouble with.  Don't think many tach's on the Pontiac motors had problems.  Let me know if you get yours working, and I will post what I did to get mine working, if I ever do.
Thanks. 

[ta78w72]

There is no distinction between a "pontiac" tach and a "403" tach.  Those clusters are interchangeable.

[Cbled56]

Well it has almost a year since this thread has been replied to.  I still have not got my Tach working correctly, just checking to see if the others did?  I'm beginning to think mine might be in the distributor.  Please let me know if you were able to solve the problems encountered, and how you were able to solve them.  I will continue to do the same.
Thanks.