hello. I bought a 91 Camaro rs v6 and when I bought it the speedometer didn't work, among other things. today when I pulled the speedo housing off it just came off. Now, I had read there is a retaining clip so when it came off it was weird. then I looked online and realized there is nothing on the back of the speedometer gauge. There are just four female connectors that attach to the speedo head. Also I cannot seem to find the actual speed cable behind the dash cluster. Also my tach doesn't work. It will work when I try turning on the car. it will drop to 0 rpms and it will try to turnover and the rpms will jump up and after the car turns on the tach will stay pegged. Also if I have key on the ignition (accessories) listening to music, the tach will jump up and down.

 

You do not have a speedometer cable. Assuming this is a 3.1L the computer gets a signal from the transmission speed sensor and sends it to the instrument cluster.
https://www.thirdgen.org/forums/elec...meter-fix.html

 

ok thanks. I still have cluster off so ill take the circuit off and test the resistors.

 

Alright. So I removed both circuit board s from the gauge cluster and they look pretty corroded. Another issue I had was that the PO had an aftermarket stereo and it was wired all weird and no lights worked on it at first. Got everything sorted out but after I bought another stereo and installed it, the right speaker was shorting out with the original speaker wire. So I ran new wires from head unit to speaker and it worked fine. After that when I turned my blinker on to the right the front light would stay solid and nothing happened to the rear light. Now, when I removed the circuit boards from the cluster, my blinkers are working fine. Is there anyway to replace the circuit boards?

 

There is a resistor on the board that is a common failure point on the later model electronic speedos. You may want to read up on how others diagnosed and repaired the board.

https://www.thirdgen.org/forums/elec...92-camaro.html

 

To check to see if the ecm is getting the vehicle speed signal.

The service manual states the vss signal depending on speed the input side is from 1-5v so your good there. The signal from b11 is from less than 1v to4v with the key on and the car on stands in drive or driving. if that is within the range you have a speedometer issue.

 

so I attempted to clean the circuit boards last night with alcohol and a small brush. cleaned up a bit but after I installed everything back on to test it, when I turn on my blinkers, the high beam indicator comes on but not the lights. so I will test all the connections and maybe take em to a pc shop to have them repaired.