Background: I have my cooling fan (within a year old mind you) connected to a toggle switch via the spliced PCM method. My switch ground has a diode soldered in the middle so a CEL isn't thrown (it would without it). Two wheeling trips ago, a CEL was thrown with the switch on but the fan still worked. Last wheeling trip, no cel and the fan worked... until it didn't.

The connector for the fan appears "burnt" (see picture) and the ground wire leading to the fan appears darkened too.



Could I have fried this? Also, my big question is, if everything is in working order, should I read power from the other wire when the ignition and auxiliary fan switch are on? I should, right? My test light is showing nothing.

I still have testing to do, mainly to my switch ground wire, but I think I may just hardwire the fan to a toggle switch and bypass the PCM's control of it all together. Thoughts on doing that safely?

 

If you are going to bypass the PCM, just use a simple 30 amp relay and wire it directly to the battery (on a switched relay of course).

Have you checked the fan relay? I think you can use a paperclip to jumper the relay to kick the e-fan on for testing

 

I'm not getting any voltage from the wires leading from the harness to the fan though. I'm getting power to the switch, but none to the fan. Am I supposed to?

 

The fan managed to come on... and almost immediately turned off. If I unplug the coolant temp sensor, it doesn't come on either.

 

Get (or make) some jumpers and run straight power and ground to your fan and see what it does. The problem may be the fan itself.


If you are going to install a switch, read this:

https://www.cherokeeforum.com/f51/ri...-e-fan-212243/