+ AC problem + (update - no, its not fixed!)
06-05-2006, 02:10 PM
#46
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Originally Posted by SharkSkin
Not sure -- I have to run off to work, and I'm less familiar with the physical layout of the wiring on later cars. The freeze switch is up in the cowl area near the windshield wipers, under that plastic cover.
06-05-2006, 02:31 PM
#47
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Originally Posted by DANdeMAN
..So the 12V should come in from the right(in my case) wire in to the switch and out the left terminal. Is that correct?
06-05-2006, 03:37 PM
#48
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Dan,
With ac switched on and with a functioning freeze switch in the closed position, both sides of the switch should read the same and it should be 12V compared to ground. If one side is 12V then your ac relay is at least getting power to the FS. Since both sides should be showing the same voltage at starup I suspect the switch is bad.
You can jumper the switch to see if that makes the compressor run. Use jumper only for a minute or so to test. On the other hand IIRC your freeze switch may be telling you that you are very low on freon.
With ac switched on and with a functioning freeze switch in the closed position, both sides of the switch should read the same and it should be 12V compared to ground. If one side is 12V then your ac relay is at least getting power to the FS. Since both sides should be showing the same voltage at starup I suspect the switch is bad.
You can jumper the switch to see if that makes the compressor run. Use jumper only for a minute or so to test. On the other hand IIRC your freeze switch may be telling you that you are very low on freon.
06-05-2006, 03:45 PM
#49
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"On the other hand IIRC your freeze switch may be telling you that you are very low on freon."
No. I goofed. That's the pressure switch on the side of the receiver/dryer, that stops your compressor from working with insufficient freon.
No. I goofed. That's the pressure switch on the side of the receiver/dryer, that stops your compressor from working with insufficient freon.
06-05-2006, 06:31 PM
#50
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OK, just to be safe and to not blow anything : I can JUMP/CONNECT the two purple/yellow wires (disconnected from FS) from pic 2 (for a short time) without ill effect to the electrical system. Is that correct?
06-05-2006, 06:58 PM
#51
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Dan,
With the assumption that there are no damaged or shorted wires you should be able to jumper the two wires pulled from the freeze switch. This should do no more damage than a normally operating switch would cause. This should activate the compressor clutch and the air valve which increases throttle speed when ac is on (assuming your MY has one). This circuit is fused and should be safe even if there is an internal short in compressor clutch.
Alternatively, and no more safe, you could provide 12V from the jump post to the compressor clutch maybe use a 10Amp in-line fuse. You are trying to find out if the FS is bad or the clutch is bad or both.
Again I think these tests should be pretty safe with routine cautions and assuming decent wire conditions.
With the assumption that there are no damaged or shorted wires you should be able to jumper the two wires pulled from the freeze switch. This should do no more damage than a normally operating switch would cause. This should activate the compressor clutch and the air valve which increases throttle speed when ac is on (assuming your MY has one). This circuit is fused and should be safe even if there is an internal short in compressor clutch.
Alternatively, and no more safe, you could provide 12V from the jump post to the compressor clutch maybe use a 10Amp in-line fuse. You are trying to find out if the FS is bad or the clutch is bad or both.
Again I think these tests should be pretty safe with routine cautions and assuming decent wire conditions.
06-05-2006, 09:13 PM
#52
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Originally Posted by j.kenzie@sbcglobal.net
Dan,
...You are trying to find out if the FS is bad or the clutch is bad or both.
...You are trying to find out if the FS is bad or the clutch is bad or both.
06-05-2006, 10:21 PM
#53
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Dan,
If you are very low on freon you may also have to very briefly jump the low freon pressure switch on the side of the receiver/dryer. This basically forms a continuous chain from climate control unit to AC relay to freeze switch to low temp switch to compressor clutch.
If you are very low on freon you may also have to very briefly jump the low freon pressure switch on the side of the receiver/dryer. This basically forms a continuous chain from climate control unit to AC relay to freeze switch to low temp switch to compressor clutch.
06-05-2006, 10:51 PM
#54
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Originally Posted by j.kenzie@sbcglobal.net
Dan,
If you are very low on freon you may also have to very briefly jump the low freon pressure switch on the side of the receiver/dryer. This basically forms a continuous chain from climate control unit to AC relay to freeze switch to low temp switch to compressor clutch.
If you are very low on freon you may also have to very briefly jump the low freon pressure switch on the side of the receiver/dryer. This basically forms a continuous chain from climate control unit to AC relay to freeze switch to low temp switch to compressor clutch.
I jumped those and the fan went on...
06-05-2006, 11:36 PM
#55
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First pic is refrigerant high temp switch. When it closes it trips the AC fan relay. That's why your fan came on. It's independent of AC compressor function. The fan comes on for high coolant temp and I think high transmission temp too.
06-06-2006, 03:13 AM
#56
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Yeah, sorry I didn't look that closely. I had a meeting maker arrive in Outlook just as I saw your post. It was for a 10:30 at the office -- and I was still at home! 
Your measurement of 12V on one wire and nothing on the other indicates that you are getting power from the HVAC relay. As Bill mentioned, it may still not have enough current. You could find out if that's the case by connecting that wire that was hot(at the freeze switch) directly to the compressor with a jumper wire -- only do this for a few seconds to see if the compressor clutch engages. If it does not, but when you connect the compressor clutch directly to the jump post(via a fuse) it DOES engage, then that indicates that the relay is not passing enough current.
BTW, when I suggested you look for 12V on either side of the freeze switch, I didn't expect you to pull the wires off.
Dave McK does a good job explaining what you should be looking for there.
With the low pressure switch you will see the same thing, 12V on one wire if both are disconnected, 12V on both if they are connected AND the switch is OK AND you have at least minimal system pressure.
Clear as mud now?
Your measurement of 12V on one wire and nothing on the other indicates that you are getting power from the HVAC relay. As Bill mentioned, it may still not have enough current. You could find out if that's the case by connecting that wire that was hot(at the freeze switch) directly to the compressor with a jumper wire -- only do this for a few seconds to see if the compressor clutch engages. If it does not, but when you connect the compressor clutch directly to the jump post(via a fuse) it DOES engage, then that indicates that the relay is not passing enough current.
BTW, when I suggested you look for 12V on either side of the freeze switch, I didn't expect you to pull the wires off.
Dave McK does a good job explaining what you should be looking for there.With the low pressure switch you will see the same thing, 12V on one wire if both are disconnected, 12V on both if they are connected AND the switch is OK AND you have at least minimal system pressure.
Clear as mud now?
06-06-2006, 05:53 PM
#58
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Well, today I jumped the LPS(low pressure switch) - finaly found it, esealy mist if you go to fast - and nothing happened. Went back to the FS and jumped it and a very crisp clean "CLICK" sound came from the front. As soon as I can get someone to look for me, I will start the engine and check the compressor clutch.
So far, it sounds promessing...
So far, it sounds promessing...
06-06-2006, 06:21 PM
#59
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Sounds encouraging. The LPS jumper probably didn't do anything because your pressure was OK and the switch was already closed. Sounding like maybe a bad FS.
Good luck
Good luck
