97 Explorer 4.0 SOHC A/C on/off switch

[vlad82]

Hey guys, i need some help with an A/C issue. My A/C fuse (N18 i think) is constantly burning. I think it is a problem with the switch. Had the same issue last year and changed the whole panel. Can somebody tell me how i can test if the switch is working properly ( when turning it on, the fan blows but the A/C does not turn on.) At the back of the switch i have 4 pins with vacuum under them. Which two pins should i connect to ignore the switch itself and start the compressor? I have photos attached of the back of the switch - pin1, pin2,pin3,pin4.

 

[J_C]

I'd doubting that a bad switch would blow the fuse, and can't imagine a replacement panel burning out in only a year same as before without some other problem.

Seems like it could be a bad compressor clutch, but I'm guessing you should be able to use a multimeter and while checking at each switch setting where A/C compressor should come on, you should measure continuity between two of the four pins, and so on with each different A/C-on switch position till all 4 are mapped out as to function.

Making a guess, I would guess that either the right most or left most pin will turn A/C on when connected to any of the other 3, but I'd never start connecting pins without getting some continuity readings with a multimeter and checking what pins on the mating connector are supplying power or ground. Edit: If you short power and ground together you'll blow a fuse at the very least.

 

[vlad82]

Those are the actual colors of the wires - Red/orange (possibly +), black (possibly -), purple, white/purple. The question is I connect which two...?
I am not very good with the multimeter, continuity, etc.

 

[J_C]

I wish a picture helped but it's just a few colors like expected, though it's better to have it than not. If you want to get into DIY electrical repairs you need a multimeter and to become friends with it.

You might still be able to find a service manual for colors and connector pin purpose but until then, it's about measurements unless someone else has had this problem, which would be ideal but nobody posted anything yet...

 

[koda2000]

I agree with J C in that I doubt the switch would be causing fuses to blow (especially as you've replaced it once). You either have a short in the wiring or A/C clutch. Try unplugging the clutch for a while, but continue to use the A/C settings as normal and see if the fuse still blows. That should help narrow it down.

 

[bobflood]

It's virtually impossible to chase electrical problems without wiring diagrams. Great source below. Diagrams usually will identify wire colors and pin numbers. Good luck.

Auto - Online Repair Info
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Select: Auto Repair Reference Center
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Follow prompts down to Wiring Diagrams.