castironman

Hello, guys. This is the problem I am having.
2 weeks ago, my Jeep ( 02 GC laredo, auto I6 125k miles ) started overheating. I took a look, no MIL but it would not turn on the fan. I checked the gauges, they work, so I checked the temperature sensor then I suspected the relay under the headlight was bad, I disconnected the relay and jump the fan, it worked, so I replaced the relay with one from Napa. It worked nice, but this week the check engine light came on, code P1491 - cooling fan relay open/short circuity. I got another relay from Napa ( it was fried or defective ) and tested the amperage on the fan, it was pulling 32 amps so I replaced the fan also - it was rusted inside. Also the relay came with a new plug in the kit, so I replaced the old plug. I checked the plug installation, had 12 v coming from the relay fuse, fan would come on jumped on the plug ( < 1 amp with new motor), ground wire with 0 ohms - good ground. Now I am back to the beginning, where the truck overheats but it will not give a code, it turned on once by pressing the A/C button but it went blank after. The original relay was replaced few years ago and the first one I replaced the chip inside was toasted ( I opened up it to take a look...).
Is there another temperature sensor that turns on the relay through the PCM ?
Would the next step be check the wire from the pin 17 to the connector ? Would anybody done that before ? Should I get a relay from the jeep dealer ?
I searched through the forum already and the internet and could not find too much info, other than this is a common problem with this Jeep.
Thank you for any help here, have a good day.

castironman

Well, I had a failed relay. I open up the relay and there was a cut across the planar board, it is black on the attachment. So I got another one from Norwood made by Standard - made in USA this time. It is working just fine, I isolated the A/C as the problem, but it may be just a cheap board. I soldered past the broken part on the board and I will use it to test it, I will have to redo the splice to the ground - the black wire and see how it will work. It is pulling 24 amps on the fan side and it is not enough wire or leg on the controller top run that, I find amazing it works at all. No wonder why it fries. See the pics.