aux fan failure confirmation

[DTM_Theory]

Just recently completed my cooling system overhaul, and I decided to test temps while the A/C being on. I noticed the aux fan wasn't turning on at all. Even after a roughly 15 minute drive with temps fluctuating between 92-96c. I suspect this is the reason why it snook up to 98c for a moment while at a stop light, without the a/c on. Ambients temps were about 57-61F during the drive.

after some searching here i've tried a few things;

- turned on a/c with the car on; aux fan didn't turn on

- tried unplugging the a/c pressure switch, a/c on, with car running; aux fan didn't turn on.

i'm on the verge of replacing the aux fan myself but i'd to know if there's anything else i can try before making the purchase. Could this be an issue with the wiring harness possibly?

thanks