A/C problem solutions?

Check for shorts in underhood wiring to compressor and for a shorted compressor clutch coil too.

----------------- The SnoMan

Are you sure it's supposed to be a 10 amp?

All mine are 30 amp, newer vehicles but still 10 amp is very low.

Thanks for responding:

No shorts I can find. Would you or anyone else know the correct resistance for the clutch? It's not at a dead short at this time but perhaps it's only partially shorted? :(

dennis in nca

On this 4runner the 10 amp feeds the A/C amplifier which feeds a couple of relays and a thermister in addition to the A/C clutch. There's also a 20 amp which feeds the blower motor, etc.

dennis in nca

Would anyone know of other groups or sites that might have some info? Thanks all.

dennis in nca

Have you tried to unplug the magnetic clutch and measure voltage at the plug. If you get proper voltage and the fuse doesn't blow, it points to the magnetic clutch. If it does blow the fuse, keep searching but you know it's not the magnetic clutch.

Paul.

Thanks Paul. That sounds like a good idea; I'll try it in the morning.

dennis

Well I isolated it to the clutch (or wiring to same).

Couldn't get at the wire loom connection (it's buried on top of the compressor); I can't reach it without pulling the compressor. What I did was to hammer out flat the ends of some finishing nails and put these ends into the amplifier connector and used jumpers (from Radio Shack) to connect to the board. I didn't connect the power wire to the compressor clutch (black with yellow stripe) and when I fired it up the fuse did not blow. On the other hand, with this hooked up with the clutch wire in the circuit "POW", one more fuse bites the dust.

Looks like another job is on the list.

Thanks to everyone for reading and for those who could help.

dennis in nca

From a post on A/C problems, some good reading on the controls associated with the A/C. Paul.

Info tip I found:

just right click -highlight & copy and paste in your address bar to open.

Check the resistance of the stator coil (magnetic clutch) with a ohm meter.

Mine was damaged from battery acid (I guess) and blowing the fuse just like that with 2.6 ohms resistance. It worked fine when testing with a 12 volt (15 amp fuse) power source and fooled me for quite awhile. :/

GL Dan

fuse) power source

Just remember that a magnetic coild has static resistance and a actaul impedance when powered and clutch pulled in. (it will vary)

----------------- The SnoMan

fuse) power source

Woops, forgot to type the specified range was 2.7 - 3.2 ohms at 68f degree.

fuse) power source

What you are really looking for here is a short or a open (a short in this case because a 2.5 ohm reading or a bit less does not always mean it is bad.

----------------- The SnoMan