98 cutlass instrument cluster failing

[sjlabash]

Hi,

I have a 98 olds cutlass, 3.1L vin M engine 4 door sedan. The instrument cluster does not work shortly after driving, except for the turn signal indicators. Sometimes everything works except the fuel guage. The problem 1st occurred after about 20-25 minutes of driving then all indicators died. Most went to zero or stayed where they were currently positioned. I did record the odometer reading when refueling while the instruments were working. The instruments went dead soon after leaving the gas station and when I was home around 15 miles later, I noticed the odometer reading was the same after getting the instruments working again. I would just like to know where the odometer mileage is stored. The other thing I noticed when this 1st started to fail, is that if I got the RPM's up close to 5, the instruments would start working momentarily.

Thank you in advance.

Sam

[maxwedge]

Stored in the pcm.

[Tech II]

Could have a bad ground, bad connection at the harness to the I/P, circuit board problem.....

If you bang on the dash, does anything happen?

Could have "B", "U", or "P" codes set....

[sjlabash]

Thank you.

Are you certain the PCM stores the mileage? I would think I would have other problems relating to the PCM and maybe a Check Engine light turned on too?

I had the codes read at Autozone and no codes found. I think their scan tool probably only reads p codes though. The Service Vehicle Soon light does come on a minute or 2 before the cluster shuts off, so could this SVS light indicate a B code? I'm not familiar with U codes. In some ways it would seem like a bad connection, but why does it work for a bit and then shut off. Heat appears to be a factor. Also, I would think it would be off from the start some of the time. Maybe a bad solder joint? I pulled the cluster out and reseated the connector with the same problem. I'm going to check the hot and ground connections next time after it dies. I may wire separate hot and ground to the cluster and see if that works.

Thanks again for your help.

[sjlabash]

There are 2 gnds to the instrument cluster. I checked both grounds and one of them fluctuated in the 10 ohm range. The other gnd was around 0.2 ohms and was stable. I ran a separate ground to that pin and the cluster began to work. I am going to trace the bad gnd wire to determine where the problem is located and determine if any other gnds are connected there. If the connection is corroding, something else may fail down the road.

Thanks again for your help.

Sam