My fan isn't comming on with A/C or high temp. When I put the ac on I can hear the relay in the fuse box click on and the one on the jdm harness click and they cyle with the A/C compressor. With the truck off key on Im getting a voltage reading of 12.xx at the low speed connector at the fan. When I jump the a/c relay it grounds out that reading to 0 volts??? Im starting to think the harness wasn't wired correctly but I looked at there web site and it seems to be. Any ideas?

 

 

Full Instructions.

http://web.archive.org/web/200212020...m.com/id78.htm

 

Thanks for the pics. I think I found the problem. The fan would only work if I used the manual toggle switch(hi speed) So I decided to switch the wires so the high speed toggle wire would be in the place of thebrown low speed wire. And when I turned the toggle on the fan did not work. Si my guess is the fan is toast on the low speed side hence the reason its over heating the truck and not turnin on with the A/C...Am I on the right path??

 

you could disconnect the fan and test low speed and high with jumper wires

That would answer your question

 

jump 12 volt wire right to the brown wire on the fan and make sure it's grounded. If it works, then you have a good fan and bad something. Follow the above diagram with a test light, preferably a voltmeter.

If the manual switch works ok on the high speed, your are fine. Make sure the relays have a real good ground!!!