Truck Repair: Odometer not Working in 1991 GMC 1500, vehicle speed sensor, gmc 1500

Question
Van
I have a 1990 GMC 1500 XCAB Truck with a 5.7 eng and 4 speed auto transmission. My odometer is not working.  My speedometer is working fine.  I have been told by some that it is a problem in the instrument cluster; others have told me it is a sensor near the transmission.
What do you think?

Also, if it is the cluster, do I have to buy the whole thing?

Thanks

Eric Starkey

Answer
Hello Eric,
The VSS, or vehicle speed sensor is in the transmission, and sends a pulsed signal to the instrument cluster.
That signal is used to operate the speedometer, is used by the cruise control, ABS, and the odometer.
If any of them are working, then that part,(VSS) is ok.
I have had the odometers quit also.
Even though the odometer uses that signal, the odometer itself is mechanical, driven by a little electric motor.
The motors I had the problem with were ok...it was the actual number counters that were locked up.
You can take the instrument cluster out, and take it apart to get to them, and some Liquid Wrench, or other lube did free one of mine up, but only for about a year.
The correct proceedure is to take the cluster to a Chevy Parts department, and they will send it off, and have it rebuilt.
I understand it only takes a few days, but I didn't do it.

The truck can be driven with it out.

There are aftermarket digital instrument clusters that will fit that truck I believe, if you are interested in that stuff. I saw a pic the other day, and they look futuristic and cool.
Go to this site and do a search.
www.chevytalk.org/

Van