AC Compressor Has No Power!

[yoyo13131]

I have a early 1993 Eclipse 2.0 GS with an R-12 system.

My ultimate goal is to find out why my compressor isn't getting 12 volts...

Compressor clutch does work, resistance is perfect. Compressor ground is good.
Just replaced the Accumulator and replaced o-rings on compressor. Opened up the ACCU (Air Conditioning Control Unit) and don't see ANY sort of burning or leaking capacitors. AC Switch works, tested with volt-meter. Don't know if Dual Pressure switch is working so I jumped it while testing. Opened up my ECU also and its flawless.

Is it possible for the magnetic clutch relay to be half working? because both my clutch relay and fan realy both don't have continuity on terminal 2 and 4 and give a reading of "70 ohms"

I had it charged yesterday with R-12 but my compressor clutch wasn't engaging because its not getting 12 volts...

any ideas?

 

[dented_coffee]

How did you get it filled with R-12? I thought that R-12 was no longer made and it was switched off to R-134A! I would really like to kow what shop filled it with R-12. Alot of people with R-12 retro-fit the AC system fitting to convert to R-134A fittings.

 

[yoyo13131]

Almost all shops in Cali charge R-12, I went to the toyota dealership and they did it for me.

anyone know how to test my ACCU? (Air Conditioning Control Unit)???!

or how to find a short in the wiring harness side of the AC clutch power wire?

 

[WORPeclipse]

You may have a freon leak. A lower pressure switch will keep it from doin it. If the freon drops in pressure the low pressure switch wont let the compressor turn on to keep from burnin it up. You could also have a bad low pressure switch too. You can jump it out to make the compressor kick on. After doin that check the pressure see if its right. If it is right you might have a bad pressure switch.

 

[yoyo13131]

You may have a freon leak. A lower pressure switch will keep it from doin it. If the freon drops in pressure the low pressure switch wont let the compressor turn on to keep from burnin it up. You could also have a bad low pressure switch too. You can jump it out to make the compressor kick on. After doin that check the pressure see if its right. If it is right you might have a bad pressure switch.

I noted I "Jumped the dual pressure switch connector" so your statement is correct, but this is ruled out by me jumping the connector with a paper clip and going around the switch just in case its bad/not working.

any other ideas?

 

[JusMX141]

If it's driving you that crazy and the replacement part could be rather expensive or hard to find, why not make a permanent power source for the compressor clutch and tie it into a toggle switch on your dash somewhere?

Obviously you won't want to run the compressor when the system is empty, so you'll have to be careful not to run the system discharged if you have a major leak or you'll damage the compressor.

 

[WORPeclipse]

I missed that part.
Have you tried appling 12v directly to the clutch to see if it will pull in? Also a way to check that switch is to check continuity on both sides of it if its correctly charged. I will look at the FSM wiring diagram this evening and see if there is anything else in there that could be the prob.

 

[yoyo13131]

I missed that part.
Have you tried appling 12v directly to the clutch to see if it will pull in? Also a way to check that switch is to check continuity on both sides of it if its correctly charged. I will look at the FSM wiring diagram this evening and see if there is anything else in there that could be the prob.

I did try applying 12v directly before I completely rebuilt the compressor and it kick on perfectly, I'll try again since I replaced all the o-rings and shaft seal. there's no continuity on the duel pressure switch because all my freeon already leaked out on my highside port, so I jumped it knowing theres no freeon (I got a replacement valve for free) (for the people that might say I didn't put the compressor back together correctly wouldn't cause my compressor to have no 12v power at the coil connector)

I'm going to the Pick-N-Pull's head quarters in Newark tomorrow to pick up a few ACCU's (Air Conditioning Control Unit) to see if that's my problem. Or it could be my thermo-switch? even though my thermo switch and inlet sensor reads good 1,300 ohms.

If it's driving you that crazy and the replacement part could be rather expensive or hard to find, why not make a permanent power source for the compressor clutch and tie it into a toggle switch on your dash somewhere?

Obviously you won't want to run the compressor when the system is empty, so you'll have to be careful not to run the system discharged if you have a major leak or you'll damage the compressor.

permanent power source would be a hassle and "could" kill my brand new rebuilt compressor if all freeon leaks out, and I don't want to risk that. It's still a option I'm considering though, thanks!

I'd just like to clarify "jumping" the Duel Pressure Switch.
Just putting a U shaped paper clip into the harness side connector of the DPS will force conductivity correct? If so then I'm doing it correct and the used ACCU I picked up at Pick-N-Pull didn't kick the compressor on...

 

[yoyo13131]

Tested my clutch relay, its getting 12v and working for sure, dual pressure switch is getting 12 volts, Air Conditioning Control Unit is getting 12 volts, Thermo Sensor is getting 5 volts, Air inlet sensor is getting 5 volts.

Both of my ACCU's seem to be working just fine! I'm completely stumped and have NO clue what it can be now, My only option now is hooking power directly up to the compressor or paying someone $120-$200 an hour =[ Anyone know anything about AC electrics?

 

[yoyo13131]

SOLVED!

When testing your 1G AC system make sure you have the car RUNNING before doing any volt meter checks! All my tests in the "On" position was my main problem.

Evidently it was a problem with the AC compressor when I rebuilt it... my rebuild kit came with a weird plastic circle spacer, which was making the coil to far away from the clutch plate for it to engage. Once I took the damn plastic spacer out my computer kicks on every time now.

Oh and sticking a U Shaped paper clip into the connector side of the duel pressure switch DOES bypass it and send power to the Clutch Relay.

Thanks for all your help!