To All,
On my 1995 Chevy Silverado 350/4L60 the Tach, speedometer, and odometer are dead. I replaced the vehicle speed sensor, then the ignition switch, checked the fuses. STILL nothing. What am I missing or what can I look at? The gauge housing and circuits all look good.
Thanks,
Larry

Sorry I don't have a diagram of the wiring to give you specifics but it should operate like the 3 GMs I have books for. The VSS should be providing an AC signal to the PCM on 2 wires. You should be able to check that signal at the PCM when the VSS is detecting rotation with a multimeter that can read frequency. (marked Hz on the meter). By jacking up the rear of the vehicle and allowing the tranny to spin, checking the signal at the PCM will allow you to check the integrity of the wiring from the VSS to the PCM, as well as the signal at one time.

The other (output)signal from the PCM should be dealt with in much the same manner. By eliminating everthing else, you will probably find the instrument panel is defective if it isn't the wiring.

Don't forget to check for a good ground at the instrument cluster. Usually the gages have a seperate ground from that of the lights. But if some work and others don't, the ground is probably ok.

Speedy;
OK, I'm feeling kind of duh at the moment, refresh my tired memory . What is the PCM, I'm having a senor moment....
Thanks

If you are having problems in your instrument panel, you might want to take the instrument cluster out of the dash and clean the contacts that it plugs into. All of that stuff feeds through a multi-contact plug in the dash base and they have a tendency to get dirty or loose contact. once the instrument panel is out, clean and ensure the plug tabs are aligning so that they are making up properly. The fact that you said the tach and speedo are not working tells me that you are experiencing a problem that is related to both items. I am not saying that it couldn't be the computer, but the dash is definitely a common point, maybe the ground circuit. I had problems with my gas gauge and oil pressure in my 91 Silverado and the dismantle and cleaning solved the problem, found it by accident, when I was getting the serial number off of the instrument cluster. I had gone to the local dealership and they had no clue--OTHER THAN replace the instrument panel.. You gotta love those guys that just replace things for a living, and not actually think of an answer.

[QUOTE=piecesparts]If you are having problems in your instrument panel, you might want to take the instrument cluster out of the dash and clean the contacts that it plugs into. All of that stuff feeds through a multi-contact plug in the dash base and they have a tendency to get dirty or loose contact


Thanks for the help, I'll try that out tomorrow. After replacing the VSS, ignition switch, and dist connection I'm getting stymied !

Thanks to all who replied, turns out the gauge cluster WAS bad. Took it out and cleaned it, nothing. Went to the local pick and pay yard and found a clean used cluster. Went home and plugged it in....presto, problem solved ! Now why didn't I try that first ??
Thanks again,
55 Guy