I know this is an ancient thread, but I wanted to note how helpful the notes by Djinn-n-Tonic were to me on my 2006 Pacifica.

The issue was the radiator fans never coming on. Both fan motors tested good, and I replaced the relay behind the bumper. No dice with that though.

So that meant more serious troubleshooting. I backtraced the whole circuit using this thread and my alldataDIY subscription. Removed the PCM and removed all the PCM connectors, cleaned and lubed them.

So the culprit turned out to be down behind the headlight on connector C105.

The radiator relay purple/brown wire comes in to C105 on pin 4. That tested good. But on the engine side of C105 the brown/purple wire had no continuity. About an inch behind that connector that wire was worn through (most likely from rubbing against the frame somewhere).

I cut the bad part out, stripped both ends, made a mechanical connection and soldered it, and put heat shrink over it. Voila, working radiator fans.

 

I had the same problem behind the headlight the brown ground wire on the white multi plug let go on the engine side, re-soldered and bingo, fans kicked in! Thank you!!