93VettePilot

When I turn on the wipers and AC at the same time it blows the AC clutch fuse. This takes the AC control head offline and renders the environmental system inop. I can use the AC by itself no problems. I can use the wipers by themselves no problems. It requires a 10 amp fuse which blows rather quickly. 20 amp fuse will allow me to use the AC and wipers at the same time.

When running the AC and wipers at the same time I can see a surge on the ammeter and all the lights on the dash dim with each sweep of the wipers. I've looked at the factory service manual wiring diagram and can't see how the two systems are related.

Anyone ever have this problem before? Wiper motor bad? Bad ground?

Update: I fixed this problem. The Accel Gen 7 computer had low resistance in the IAC stepper circuit input line(increases IAC when AC compressor kicks on). So the AC Clutch circuit was basically shorting to ground. Not sure why the wipers surged and caused the AC fuse to blow but its fixed now.

93VettePilot

ttt

oldalaskaman

I vote , bad ground

383vett

Wipers should not be on the same circuit as the ac. They have their own breaker in the fuse panel. Someone must have rewired the car. Check the wiring and find out where the wipers get their power from and rewire back to the panel.

jfb

A bad ground would cause lower current in those circuits.

The wiper is on its own 25 amp fuse and is unrelated to the A/C system. A/C compressor clutch has its own 25 amp fuse. Check for changed wiring!

93VettePilot

Keep in mind... my car is LT1 with 30 amp wipers and 10 amp AC clutch...

I've been going through the factory troubleshooting for the wipers and I'm about 90% sure the wiper switch is bad. I still don't see how this could affect the clutch fuse but hopefully it will solve my problem.

jfb

I was using the fuse sizes from my 87 and I don't have a schematic for your year, but I am certain that there is no connection whatsoever between the wipers and A/C clutch wiring and you should not experience fuse blowing when both circuits are on! A previous owner must have rewired those circuits.

93VettePilot

Fixed. See 1st post