Charging System Troubleshooting--Blown Ignition Light Fuse?

ACHiPo · #1 (**permalink**) 05-25-2019, 07:02 PM

Got a little bit of data today. At this point I'm pretty sure the problem is not on the heater portion of the circuit.

I pulled the heater switch out of the dash and checked continuity. The light green wire is shorted to ground (not too surprising since it is connected to the W/G wire which is also shorted to ground when measured at the fuse block).

The orange wire connecting the heater switch to the heater fan is 49 Ohms, so seeing the motor windings before ground. This seems ok.

The heater switch is ok.

Because it was easy, I pulled the connector off the wiper motor just to make sure it wasn't shorted and it's not. The light green wire is still a short to ground.

It seems like the short has to be between the wiper switch and ignition light, ie I'm back to suspecting the short is at the tach or fuel gauge. Will drop the dash again tomorrow and pull the tach and fuel gauges (again). If nothing else it gives me a chance to reinstall the Smiths voltage stabilizer on the fuel gauge.

patrickt · #2 (**permalink**) 05-25-2019, 07:20 PM

Quote:

Originally Posted by ACHiPo

It seems like the short has to be between the wiper switch and ignition light, ie I'm back to suspecting the short is at the tach or fuel gauge. Will drop the dash again tomorrow and pull the tach and fuel gauges (again). If nothing else it gives me a chance to reinstall the Smiths voltage stabilizer on the fuel gauge.

Alright, I'm now betting on the tach.

Blas · #3 (**permalink**) 05-25-2019, 09:29 PM

As I recall, there was a similar issue years ago on some CSX cars. I believe it was determined the problem was in the ignition light housing. Blas

ACHiPo · #4 (**permalink**) 05-25-2019, 10:58 PM

Quote:

Originally Posted by Blas

As I recall, there was a similar issue years ago on some CSX cars. I believe it was determined the problem was in the ignition light housing. Blas

Thanks. I’m pretty sure I already eliminated that as a possible cause, but I don’t really trust any troubleshooting I did with the voltage stabilizer installed.

ACHiPo · #5 (**permalink**) 05-25-2019, 10:56 PM

Quote:

Originally Posted by patrickt

Alright, I'm now betting on the tach.

I’ll try it tomorrow, but I’m skeptical. I had the tach out of the circuit when I was blowing fuses last weekend.

I’m betting on the fuel sender, the troubleshooting of which was masked by the voltage stabilizer in the circuit.

Hopefully one of us is right!