Yet another AC question...

When I bought the car the AC didn't work. A rebuilt master control switch, a new drier unit, rebuilding the monovalve, and recharging the system took care of that, and the AC worked great until last winter when the bracket for the AC pump came loose from the engine block, causing the belt to snap. "Oh well, I will take care of that when the weather warms up" I said to myself. Bad call...

Now with a new belt installed I can only get AC if I manually apply voltage to the pump wires. Otherwise, the pump never engages. I have voltage to the monovalve no matter where the switches on the dash are set to.

Where should I go from here? I really don't want to replace that switch unit...

After perusing a few threads it seems that it may be:

1. Refrigerant needs recharging
Can I test this myself?

2. A bad relay
Which one is it?

Usually the compressor won't engage if there is not enough pressure on the system. Jumping the wires is not usually a good idea, it cuts out to protect the compressor. Get yourself some pressure gauges and you can rule that out.

__________________
TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth

OK, I only did it for a moment for testing, so hopefully no harm done. Would you guess based on the series of events that it's just a recharge that's needed? If so, I will just have it done and forego the expense of buying a gauge. (Or is recharging it myself an option? I've never done it.)

Also, what about the relay location? Any tips?

That's correct and normal. If you set the temp control to "min" (18?) one of the pins should then be grounded to close the valve; at that point one pin will have ~13 VDC and one will have ~0 VDC. (for access either slide the connector up a little, or pop the cover off with your eyeglass screwdriver)

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James Marriott
2003 Buick Regal
1983 300D (228k, frau Auto)
1996 Suburban K2500 (192k, 6.5 turbo diesel/4WD towmaster 10,000)
www.engineeringworks.biz
1987 300SDL junker 170k
1982 300SD junker, 265k

If you're going to recharge it you're going to need the pressure gauges anyway. They're not expensive - you can't get a definitive answer without actually testing so I can't help you there.

__________________
TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth