Since the old thread (IAC
+ P1000) was leading me down a rabbit hole, I thought it best to start a new one.
Firstly, über-thanks to all for this forum! It's comforting to know that whatever crops up, someone has dealt with it before, usually successfully, and sometimes even economically!
So with the car ('05, Vulcan, "U" code) now showing P1633 along with the P1000, we were pointed (by this wonderful site) toward the fuse for "AC Relay and PCM
Keep Alive Memory". In his case, that was fuse #18, and surely enough, it was burnt out.
Many posts here mentioned that the thing would burn out repeatedly unless the AC
clutch was unplugged at its source, or if the relay wasn't pulled. I suggested he do the latter, so he found one called #2 that said AC
relay, and pulled it before replacing the 10A #18. He said, however, the car wouldn't start without #2, so he put it back in, & said it now ran fine. Until he pulled over for gas a couple hours later, and #18 blew again when he started it up.
It's hard to do this over the phone, without being able to look at the same fuse box with him. However, I was kinda suspect when he told me #2 was a 30A fuse - that sounds like a lot for an AC
relay. Besides, I was envisioning a rectangular, opaque kinda relay switch, rather than a 30A fuse.
In any case, most of the threads I've found here point to either:
1) A burned-up AC
2) A short at the clutch, or somewhere along the way from the fuse to the clutch
3) A seized bearing on the clutch pulley
4) A seized AC
I'm really kinda hoping for #2, as the others sound above my pay grade and/or interest level. Plus, they sound expensive, given that the kid is 600 miles away, and has no tools available, or mechanical acumen. FWIW, he's not reported any noise coming from the engine, so I'm thinking #3 and #4 might be off the table, for now.
How would you trouble shoot this? Does he need and electrical tester to check for amps/volts/continuity along with wires? Can he just wiggle the connectors and inspect the wires to see if there are any breaks/cuts/rodent teeth marks?
PS - I saw some rumblings about the IAC
being routed to that #18 fuse with the AC
Relay & PCM KAM
. Who would decide that those 3 things even go together? I have a sneaking suspicion that the #18 fuse was the source of his original symptoms, rather than a bad IAC