01 Tahoe LT instruments and cruise inop- SOLVED

[LM7Tahoe01]

Hi there!

I’ve got an ‘01 Tahoe that lost the instrument cluster and the cruise control this morning... I was driving along like normal, and I noticed that the tach showed 0 RPM but I verified that it was still running. Next step was to check the rest of the gauges, they all read 0 (or the lowest reading) as if the key was off. Since it was running fine I continued with my plans for the day, and on the way home I tried to set the cruise and discovered it didn’t work.

When the cluster did work the voltage gauge read about 2 volts higher than reality. Truck charges at 14.5 but gauge read about 16.5. Don’t know if that’s related or just a red herring...

The truck starts, runs, and drives just fine with the exception of the cruise, and the fact that I don’t know how fast I’m going or what’s happening under the hood.

I have verified that the cruise fuse is good.

Is it possible that I have a bad ground, or is it more likely to be the infamous cluster failure?

Thanks!
Jon

Edit-I also do not have ABS or Brake warning lights key on engine off. Engine light works as it should.

 

[LM7Tahoe01]

A relevant development: if I plug in a code reader everything works. If I unplug the code reader I loose the cluster and all of the warning lights except the engine light... gotta be a bad ground right? Where do I look?

 

[LM7Tahoe01]

Fixed it! Figured there had to be some way that the code reader was supplying a ground to the cluster. Turns out that there’s 2 ground wires in the OBD connector and one of them (black with white stripe) didn’t have continuity to ground. That wire grounds to the back of the passenger side cylinder head and it was broken off of the ring terminal. I installed a new terminal with some new wire so I could splice it to the old wire farther up past the corroded end...

Everything works as it should with the exception of the voltage gauge which still reads high. That’s gotta be a cluster issue, but I’m not gonna worry about it right now because it does respond properly to changes in voltage so you can tell what the alternator is doing...

 

[exp500]

It could mean your eng grounds not that good too. Also interior by left foot I believe it is.

 

[LM7Tahoe01]

The issue with the cluster and warning lights was the broken ground wire on the cylinder head.

It certainly wouldn’t hurt to upgrade the main grounds but I don’t have any other symptoms of a ground issue.

I believe the issue with the voltage gauge reading high is a problem with the gauge itself (not exactly uncommon for these trucks…). If I had ground issues I would expect the gauge to read low not high, and I would expect to have other issues (performance, fault codes, etc)…

 

[LM7Tahoe01]

Just realized I didn’t edit the thread title to “solved” after I fixed it…

 

[OR VietVet]

Might want to delve in to these and check it all out: https://www.fixmyoldride.com/Chevro...e7e5cd24ed24635&at_ab=per-2&at_pos=3&at_tot=4

Another big 3 upgrade with questions

Just getting started on the big 3. Ive got some 1/0 100% ofc leftover from a previous project. So i started with the battery to body ground which was made out of a little scrap piece. The rest of my leftover was a couple inches too short for the alt to positive cable. So i bought a "premium"...

www.tahoeyukonforum.com