Oem wiring questions

[todd.brust 29]

My buddy recently bought a 94 Cadillac Seville, and the radio wiring was so ghetto rigged so he went to rewire everything. While wiring, something shorted and now his instrument cluster will not work at all. We pulled the dash apart and tested the power leads and the would get power right before the fuse blew and all the accessories worked fine without issues. So we figured theres a short in the factory wiring. We bypassed all the factory wiring and and gave it constant power right off the ignition and fused it the same as the factory fuse size. Still blowin fuses.

The problems arose when messing with the factory radio. The radio would cut out at medium volumes. We took a look at a very detailed manual for the car and found that there were 2 wired that came from the IPC to the Radio. There was a 16 volt output from the IPC to the radio, and a dimmer control. The dimmer control worked fine but the 16V output to the radio did not meter anything at the plug or behind the radio, so I disconected it from the wiring hoping that there may be issues in there. Still blew fuses. I think the aftermarket radio may be been wired to that 16V output for acc or power.

We then proceded to check about every input and output and everything checks out fine. The only wires I did not tap were the Airbag wires, security, and 2 data wires. Everything checked out fine.

Do you guys think the short might exist inside the IPC, like maybe something shorted inside to do with the 16V output? Thats about all I am concluding.

Any other ideas would be greatly appreciated.

Any questions about what I said can be answered too. Thanks Guys.

[todd.brust 29]

No one has any suggestions or comments?

[Aaron Clinton 2,372]

Do you have the wiring schematic for the car?

[todd.brust 29]

Yessir, Full detail with Pin Diagrams.

Everything check out fine with the exception of the +16V output going to the OEM radio. Who ever wired the radio before my buddy bought it had the +12V and the ACC connected to the 16V output on the dash. So I am guessing that it's possible that the Radio somehow shorted out that output. Thats the only conclusion I could come up with. I completely rewired the power to the the cluster and it continues to blow fuses so it has to be something internal. The only 4 wired I didn't test was a security wire, airbag wire and 2 data wires. I am doubtful that any of those are at fault.

Any help or suggestions would be helpful.

Todd