2007 Classic Speedo and Odometer (Lights up just not changing)

[dositmat]

Hello all, Tried searching my problem and couldn't find an answer, I have a 2007 GMC Classic 3500 with a duramax. The speedo quick working (Stays at 0) with the odometer (Lights up just doesn't change) and the AVG MPG not working. Lights up just frozen. Thought it was the stepper motor but just had them all replaced and works fine in another truck. I do have an edge and get the MPH there so that makes me thing the VSS is fine.

Any suggestions?

I appreciate all help in advance!
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[DAVe3283]

I believe the 2007 Classic was the last year to run a dedicated VSS wire from the ECU to the dash cluster. The ECU is getting the signal (because the Edge reads it), but the cluster is not. I would look at the VSS wire (green wire, IIRC) in the dash plug, and make sure it is not broken or shorted somewhere.

 

[dositmat]

I believe the 2007 Classic was the last year to run a dedicated VSS wire from the ECU to the dash cluster. The ECU is getting the signal (because the Edge reads it), but the cluster is not. I would look at the VSS wire (green wire, IIRC) in the dash plug, and make sure it is not broken or shorted somewhere.

Ok thanks I will check that out this afternoon

 

[onebaddmaxxx]

More inclined to just say the clusters bad. Get someone with a tech 2 or snap on solus/modus and do a sweep test with key on engine off. I bet it doesn't move

 

[LBZ_Duramax]

It's in the speed sensor, speedometer needle doesn't know what odometer is doing. If the miles aren't counting something that feeds that info to the cluster is bad. There is a wire that goes to the cluster on those models that some in the past have put a switch on to not count the miles, it would make the speedo and odometer not work.

 

[LBZ]

Before you get carried away check your fuses under the hood. Not saying that's what it is but there is one that will cut out your speedo and odo and some of the gauges if it blows. Not sure which one for sure though. Just a thought.

 

[dositmat]

Thanks for all the replies. Found the issue. someone in the past Since I am 3rd owner had T-tapped the VSS line and it was split into 2. Spliced it back and works like new.

Thanks for all the help

 

[LBZ_Duramax]

Thanks for all the replies. Found the issue. someone in the past Since I am 3rd owner had T-tapped the VSS line and it was split into 2. Spliced it back and works like new.

Thanks for all the help

That's exactly what I was talking about. Glad you found the problem