1989 K-1500 speedometer electronics

[Coal-ka-nut]

Oldie but goodie, 1989 Chevy Scottsdale 4x4. Not a rusty old beater either. Having some issues with electronic gauges. The speedometer, odometer, and trip odometer do not work all of a sudden. This in turn will not let the truck shift into overdrive, and the cruise control is in operative while this problem exists. I show a brake light on also, as well as a check gauges light once and a while. The truck is fine, and drives perfect otherwise. Just recently restored, and is a bit of personal pride on how it turned out.

I had removed the speed sensor twice and replaced it with new ones. No go.

I had the gauge cluster remanufactured by a reputable vendor. No go.

Has any one else had an issue like this? Maybe an open ground wire? Where do I look? This is a nice old Chevy truck. I would like to make her work like new. Any help out there?

 

[zora]

Have you checked for any codes?

 

[Coal-ka-nut]

No I haven't. But I do not have a check engine light on either. I'll try that on Sunday...if winter decides to leave by then!

 

[Chuzz]

It sure sounds like a ground problem to me, but I have no idea how that instrument cluster is grounded. I'd guess it's through the wiring harness, but someone else would have to provide you with a schematic or tell you which wire to trace to ground. My first thought was the VSS, but you said you replace that twice already. My only question about that is where did you get them? If at Autozone or Advance, I'd suggest trying one from you local GM dealer. AC/Delco is the way to go for a GM product.

 

[Coal-ka-nut]

@ chuzz, I got them both from Car Quest. But hell yeah, Chevy dealer is my next step. But I will also check all the chassis grounds also. Thanks.

 

[Chuzz]

I've never dealt with Car Quest, but worked for both the zone and advance in the past and as a manager, saw more electrical parts returned from failure issues right out of the box, than anything else. Next was the Factory Air a/c stuff.