My speedometer has not worked sisnce I bought the truck. I have read everything in the site on this issue, went into the manuals, and this is what I have come up with so far:


I disconnected the plug from the vehicle speed sensor calibrator in back of the glove compartment, checked the ground, which was bad, and found that the black with white wire on the right rear of the engine was not connected. Connected that, did not fix that problem, did fix my fuel gauge, and continued with a voltage check of the brown wire with the key on, which had 12VDC.

Next step was to check for an ac voltage between the purple white wire and the lt. green black wire, which I did not get a reading under low speeds, but at what I am estimating at 60 MPH I was reading .018 to .023 VAC.

I am at the point of changing the vehicle speed sensor, but as you all well know that when you purchase an electrical component, you own it!!!
I am hoping with the vast knowledge out there that if there is a chaffing issue where the wires break, or a plug somewhere in the harness that may go bad is commonplace with this beast, and that someone could enlighten me. I did check to see if the same wires that were supposed to give the AC signal were shorted to ground and they were not. Looking for devine intervention.............

Do a search for "speed sensor" some one just replaced theirs and IIRC stated that it was cheap and easy.
If that isn't the problem check out this thread. Speedo repair (http://dieselplace.com/forum/showthread.php?t=97155).

Is your trip meter and odometer working correctly?

The odometer and trip are not working at all. Everything else is working in the gauge cluster though. I pulled the panel and have checked the connections in the back of the cluster with nothing found.

I went out and changed the vss, plugged the ohm meter in to see if there was a reading or not, nothing. Started more checks, and ended up finding where the previous owner had cut the purple and green wires going to the vss, and put them back in the harness so you could not see the damage. Gotta love that!!!

I recrimped the wires together again, and the speedo did in fact start to work, but would only go to 35 mph, and no more. I know I was doing more then 65MPH on the highway this afternoon, and again it would not go further then 35. The brake light in the lower right hand corner has come on since the speedo started working, and do not know why.....

Well, back to the drawing board............................. Anyone seen this one???

I drove the truck home last night, and the brake light did not come on during start. I started to drive out of work, still no light. I believe it is some sort disagreement between the indicated speed of the truck and the abs wheel sensors, because it was not until a speed that was clearly faster then 35 that the red brake light came on in the lower right side of the instrument cluster, and stayed on for the rest of my hour commute. The brakes act fine, no issues.
If anyone has run into this or something similar, please let me know.