lately I've noticed my tach isn't functioning quite correctly all the time. sometimes it seems to get stuck maybe 600 rpm above what I'm really at, and the only way to fix it is to push the clutch and let it idle down. it'll drop normal to about 2000/1500, then it just falls the idle. I wonder if this has to do with my alt gauge not going over 10, even though I know it's charging? my lights aren't dim, my battery isn't dead, etc etc.

I made sure my connections on the ignition are good, cleaned them all up with a scotch brite pad to shiny metal. also did battery terminals and body ground. where else should I look?

Don't know if this helps but it's a 85 GSL, 12a.

 

Hmmm. My tach needle used to get stuck around 4k rpm. I found out it wasnt a electrical problem I had. Just cause the last time I touched the needle when instrument cluster was out I pushed it in too much. Possiblilty its stuck or something...

 

bad ground?

 

I haven't touched the cluster yet(although I'm going to be replacing the clear plastic soon), and I haven't gone digging up under the dash yet.

I think all my grounds engine side are good, guess I'll have to check dash side. I don't want to try to fit under there though, lol.

 

There are 5 grounding points as well as the main cable going to the front, long bolt of the starter. One is on the left shock tower where the main battery cable also connects. Another is on the right side of the engine compartment near the headlight retractor. A third is inside the car, on one of the bolts holding the plate at the base of the steering column. These three are connected to the "Front" harness, therefore they are called Ef on the wiring diagram. Ei is located in the center console on the left side of the stereo opening. It is connected to the "Instrument" harness. Er is connected to one of the mounting bolts for the hatch latch. It is connected to the "Rear" harness.

If you have already cleaned the battery cables, it sounds like you may need to replace them. The original cables tend to corrode internally. I always do the negative cable first.