I bought an 05 Jimmy in October last year and have been rebuilding it to get it safetied. I’ve put close to 1500 in new parts, but the last thing I need is the Speedo and Tach to work.

The speedo worked a couple times randomly after I bought, but hasn’t worked since December. The Tachometer worked when I bought it, up until I pulled the cluster to replace the stepper motors. When I reinstalled the cluster, the RPM and KPH did not read. I also noticed this instrument cluster is not the same year as my Jimmy, but likely a 2000-03 Sonoma cluster (cluster has large Air Core stepper motors, compared to plastic ones I’ve been replaced in videos).

I took the cluster to a mechanic who rebuilds old GM clusters. When he bench tested it, he said everything started up fine and zeroed out, so it must be a wiring issue inside the truck.

the OBD reader is pulling a p0650 code, stating a burnt out check engine like. I’ve read this could be caused by a fault in the pcm. My ABS is acting up(activating below 10kmph) and I’ve ordered a new passenger side front hub with sensor(sensor was reading 150mV while driver side front was reading 350mV). I hope this new hub fixes the issue.

could anybody else weigh in on my situation? Could it be a wiring issue under the dash? (I did a heater core replacement and want to check for pinched/broken wires)

I’ve had my mechanic print out schematics and suspect the Cruise control or the splitter bundle as well. Any help here?

 

The first simple check is that you have intact fuses and proper voltage for all the IPC power feeds:

cruise fuse 3
gauges fuse 4
Clstr fuse 11
RDO batt fuse 19

If those all check out then There is:

Power to all 4 IPC inputs
IPC grounds
wiring (start with A3/tach out PCM to IPC & A4 VSS PCM to IPC)
connectors
splice packs
VSS sensor on the trans
PCM

Let me know if you need help with any of these or wiring diagrams, I'll be glad to help.


George