View Full Version : Gremlins
cnutting
10-07-2017, 08:26 PM
So... Not sure why this is, but my fan quit working. I am running it off of the thermostat, no override switch (that may change). Worked fine until last week. I had moved the ground wire, and did find a crappy ground and a bad crimp which I changed. Soldered the connections, and have a nice solid ground. Fuse is good, I think the solenoid is good. Going to dig into it tomorrow as well as some other electrical issues, but wasn't sure if there were some obvious items I should be checking?
Tips and suggestions welcome. Please go easy and use small words, I'm a lowly mechanical engineer...
2bking
10-07-2017, 08:58 PM
I'm a lowly ME also. A Volt-Ohm meter will find your problem quickly. Start by finding how far the +12V gets going toward the fan when the engine is hot enough to need it and then with the +12V disconnected, check for less than 1 Ohm in the wiring going from the fan to ground. A little logic should find the problem area such as thermostat, fan, or wiring.
boat737
10-07-2017, 10:10 PM
Put 12v to the fan motor as well, make sure the fan motor is OK. A Power Probe is wonderful in these areas.
cnutting
10-15-2017, 12:48 PM
I have isolated the issue to the thermostat. Not sure what happened, but it doesn't ground out at temp. All the other connections and the fan motor itself work fine. So... Next step is to replace the thermostat.
On another note, riddle me this...
My hazard circuit seems a bit off. The fronts work fine, but the backs do not function. Here's the quirk, the directionals work fine both front and back. The hazards don't work on the back unless the brake switch is activated. Then everything is fine. I tried turning on the headlights as well as the high beam circuit to see if there was something there, but the rear hazards only activate when the brake pedal is pushed.
So... the wiring seems correct, the flasher unit is good and the lights themselves function. I am questioning the trailer adapter (this is a 289 FIA with the rectangular taillights). Going to start tracing the circuit again with the meter, but I'm interested to see if anyone else has encountered this gremlin before.