OT: 89 Chevy Truck Question

Danny in CO · Apr 17, 2014

I'm looking at a 89 Chevy 4x4 truck to buy. The owner says the speedometer works but the odometer doesn't. Are the speedometer and odmeter driven by the same mechanism or separate. I know older Chevys had a gear in the side of the tranny with a cable that went to the back of the dash to drive the speedometer and odometer. I don't know how the newer ones work.

Any ideas?

Thanks,
Danny

Bob · Apr 17, 2014

Speedo is electric... basically a voltmeter driven by electronics.

Odo is a mechanical counter driver by an electric motor whose speed is controlled by electronics. Those were prone to strip a little nylon gear. Does the odo twitch every tenth of a mile and give a tiny "click"?

4play · Apr 17, 2014

Yes, they get the same signal, same vss and wiring. If one works and not the other then the problem is in the speedometer head assy. This is a pretty common problem on these trucks, particularly the 88-91 round dial gauge clusters.

Does the trip meter work? The trip and odo operate on the same motor so its common that both fail but if one works and not the other then maybe a gear is stripped for that one. Since the problem is common you might not have good luck finding a salvage part but its worth a shot.

dbNga · Apr 20, 2014

My trip meter stopped due to the push button reset is connected to a fork and the fork broke. Speedo and odo are still working fine showing 296,xxx miles.

OT: 89 Chevy Truck Question

Danny in CO

Well-known Member

Bob

Well-known Member

4play

Well-known Member

dbNga

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