C 131 Issues 89 325is

[robert1700]

My coolant gauge stop working and I am getting 0 volts at the connector near the thermostat. I built a wire from the thermostat to the fire wall but I can not find where to splice this into, no brown/purple wire? Anyone know which wire?

Thank you

[jlevie]

The only convenient place to get to the wire is behind the cluster. But have you verified that there is an open circuit from the cluster connection to the sensors. A dead temp gage is quite commonly from a bad SI board.

[robert1700]

SI board and gauge is fine, I had to re-wire the c131 plug. There is a dead wire coolant temp sensor still,

[jlevie]

I think you are talking about C191, which is the connector under the intake manifold. If you have continuity from the cluster to the engine harness side of C191, the problem is in your "rewire". I hope that was done by replaced one or both sides of C191 rather than splicing the wires. If you spliced the wires the next person that needs to remove the intake manifold will curse you loudly and for a long time.

[nando]

SI board and gauge is fine, I had to re-wire the c131 plug. There is a dead wire coolant temp sensor still,

which sensor? the dash CLT sensor is only 1 pin, but there are still two wires to it. the second wire doesn't go anywhere.

[jlevie]

which sensor? the dash CLT sensor is only 1 pin, but there are still two wires to it. the second wire doesn't go anywhere.

Close. The second wire (brown) isn't used, but it does go to ground.

Which leads to the possibility that the sense wire and ground have been swapped.

[robert1700]

All along it was the sensor, oh I made this way harder than it had to be