'92 Tercel A/C - pressure switch

The A/C on this '92 Tercel that I bought very used isn't working. The switch turn on on the panel. The system has been converted to R13A. THe compressor doesn't turn on.

Assuming that there's no pressure in the system, I'd like to jump the pressure switch to see if it the compressor works. Can someone point to the A/C pressure switch on this little car? Is it accessible from under the hood or is it under the dashboard?

TIA,

Fred

Reply to
Cornerman
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I'm not specifically sure on your Tercel Fred, but look for a wiring harness that follows the refrigerant lines and has a connector(s) to the line in one or two areas. Unplug the switch(s) connectors and jump them. Only do it momentarily.

Reply to
user

If you want to check if the compressor works, you should jump the magnetic clutch on the compressor. The connector for the magnetic clutch is just behind the clutch/pulley on the compressor. As Ph@Boy mentioned, do this only momentarily to see if the clutch engages and the compressor turns. While you do this, take a look at the sight glass on the receiver/drier - if you see white foam, the system needs evacuation and charging.

Reply to
Ray O

This sounds easier. If I want to recharge, can I jump this magnetic clutch this way for long enough time?

I unplugged that magnetic clutch connector. Excuse my ignorance, but there are four wires on the connector. I can't find a good explanation in my Haynes to tell me which connection is which, and what needs to be jumped.

Fred

Reply to
Cornerman

Would need a charge fer sure, but only an evacuation if the pressure dropped to zero when not in use. IE: if it's totally empty, always pull a vacuum, as moisture can enter the non pressurized system. But if the system was never totally empty, even if only 5-10 lb's of pressure, you can just recharge. Moisture can't enter a system that has pressure, even if low. I usually jump the pressure switch when checking a low, or empty system. "it's usually easier to get to, and only need a simple wire clip to jump" But it's possible to have a bad relay, or even clutch, etc, so I'd jump the clutch if it didn't run while jumping the pressure switch. The quickest way to see if it needs a vacuum is to just poke the shrader valve on the suction line. If it's got pressure at all, you are ok to recharge. If nuttin... Time to look for bad leaks, and time to whip out the vacuum pump when it's recharged.. And if it's been empty a good while, I'll usually run the pump a good while to make sure all the moisture is boiled out. Maybe an hour or so.. But I have good vacuum pumps... I don't recommend homebrew pumps, say from refrigerator compressors, etc.. They suck at sucking...Fairly useless.. They don't pull down low enough to boil the moisture out in most cases. MK

Reply to
nm5k

Yes.

2 of the connectors are for the compressor RPM sensor and 2 are for the magnetic clutch. With the engine off, apply 12 volts and ground to the terminals on the compressor untill the compressor clutch engages to find out which terminals are for the clutch.
Reply to
Ray O

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