So, yesterday while making a parts run for a buddy, while at a red light, I noticed my Tach was sitting on 0.. Truck was clearly running, idling at approx 8-900rpm at the time.

For a few seconds after I left the light, the tach read close but a little off, it would return to 0 at idle (coasting with clutch in, or stopped) then it would return to 200, then 500 then after a few seconds it returned to normal.

I figured whatever, the cluster had a brain fart or somthing () but this morning it did the same damn thing..

So, everything else reads normal, this problem never lasts more then 30 seconds to a minute. I have NO clue whats going on, perhaps the wires going from the coil to the cluster are bad or going bad?

Any ideas?

 

Hey, I have been haveing this same problem. My tach will randomly spaz out while I am idling.

I started a thread a while back and nobody knew what was up. I know there is a wire from the ignitor to the tach and I have been to busy to check it out for shorts/breaks.

Let me know what you figure out.

Edit: here https://www.yotatech.com/forums/f116...e-help-131011/

 

Cool! Thanks for the link

I checked this out in the FSM, thank goodness its online for free!

http://personal.utulsa.edu/~nathan-b.../6combinat.pdf

I will clean the Igniter/body and body to battery grounds and go from there. If its still happening I will test the wire.

Ugh, if this wire is bad im gonna start breaking things. I already have to replace a wire going from the ECM to the TPS

 

yea, if I ever get some free time I was going to try to run a wire from the Ignitor to the tach to test it out. I need to try cleaning the contacts on the plugs and the ignitor's ground too...I hate electrical issues

 

yeah, they are the worst!

 

im having the same problem, its kinda frustrating

 

I have not been able to check anything yet, but the problem was much worse yesterday. Tach sat at zero (when idling) everytime I stopped or let the rpms come down. Then about 30 mins later it was working again.

It seems when the tach does act up, it will read rpms (when above idle) but not that accuratly.

I will try the grounds today, its raining so im not too excited to go play outside..

*edit*

okay, so I though I knew where it was but apperantly not. Where is the ground for the igniter?

 

I am pretty sure its grounded by the bracket holding it to the fender...does anybody know for sure? You could always try taking it off, cleaning the mounts and bolting it back on...

 

Well, I thought that might be it, so I pulled it off, cleaned it all off with alchohol (aswell as the bolt used) then I pulled off the battery/body ground and sanded it down, cleaned with alcohol.

I drove up to canadian tire and bought a torque wrench, tach is working great

The grounds were very dirty!

 

Thanks Jay, for post a link to FSM.