Okay, so my A/C clutch does not engage when I turn on my A/C switch. Blower kicks on but the clutch won't engage. If I hook up the clutch directly to the battery it engages. I've checked the clutch relay, it is okay, there is voltage to the low pressure switch. What else should I check? I was told, perhaps the thermostat on the evaporator may be bad? How can I check that? Or what else should I troubleshoot?

 

up

 

help

 

me

 

please

 

I had the same problem with my beater. Turned out the clutch would engage if you smacked it but wouldn't cycle as it was supposed to. All i did was go to a pick a part and get a new A/C clutch instead of the whole Compressor. Still working with 355,000 miles on her.

But first I'm gonna start with the obvious. You do have pressure in the system right. Not enough and the compressor will not engage so it doesn't burn up. At least thats what I was led to believe.

 

I've swapped a/c compressors with a known working one. I checked the low pressure cut out switch and the a/c clutch relay, both checked out okay. Recharged the freon and oil with an a/c machine. Like I said above, it will engage when given power directly from the battery, so that most likely means some switch or relay, etc is not sending current from the a/c switch to the compressor right?

 

?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by all-mtr-teg &raquo;</TD></TR><TR><TD CLASS="quote"> Like I said above, it will engage when given power directly from the battery, so that most likely means some switch or relay, etc is not sending current from the a/c switch to the compressor right? </TD></TR></TABLE>
Right, now you just have to narrow down where the problem lies. A good place to start narrowing it down is in the middle. Is the control side of the relay good? Or is the problem in the switched side?

 

I tested the low pressure switch and the a/c clutch relay, those are both good. Im assuming the a/c climate control swith is good cause when I turn that on, the blower kicks on, just the a/c clutch won't engage. What more can I test?

 

IS the condenser fan kicking on?

 

Yup

 

Ok, that narrows it down a lot. Now are you getting a ground signal to the clutch relay? And you did check all the fuses?

 

A/C clutch relay is good cause when I switch the a/c clutch and condensor fan relays, the fan kicks on with both relays. But im not getting power to the a/c clutch relay when I switch on the a/c switch inside the car, the condensor fans kicks on though. How do I test the thermostat switch, do I have to remove the dash to get to it?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by all-mtr-teg &raquo;</TD></TR><TR><TD CLASS="quote">A/C clutch relay is good cause when I switch the a/c clutch and condensor fan relays, the fan kicks on with both relays. But im not getting power to the a/c clutch relay when I switch on the a/c switch inside the car, the condensor fans kicks on though. How do I test the thermostat switch, do I have to remove the dash to get to it?</TD></TR></TABLE>
I wasn't asking if the relay was good. Need to know if it is getting the required ground signal. The ground is what gets switched to the relay. If you're not getting any power to the relay, the fuses and wiring/connectors need to be checked.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chiovnidca &raquo;</TD></TR><TR><TD CLASS="quote">
I wasn't asking if the relay was good. Need to know if it is getting the required ground signal. The ground is what gets switched to the relay. If you're not getting any power to the relay, the fuses and wiring/connectors need to be checked.</TD></TR></TABLE>

Yeah, I think that's what's happening, not getting power from the a/c switch inside the car to the a/c clutch relay, so somewhere in between there is a short. Where should I start checking, from the a/c switch side or from the relay side?

 

I guess we need to try something else. Do you have a multimeter? If so remove the relay and check each terminal in the socket for power and ground and post the results.

 

2 Relay Sockets have terminals that look like this 97 GSR
Left
[A B]
[C D]

Right
[A B]
[C D]

Left socket,
A-C no voltage
B-D 13.9 volts
A-ground on frame, no voltage
B- ground on frame, 13.9 volts

Right Socket,
A-C no voltage
B-D 14.2 volts
A-ground on frame, no voltage
B-ground on frame, 14.2 volts

ALSO, where is the A/C diode and how do you test that?


Hope this makes sense




Modified by all-mtr-teg at 9:14 PM 2/25/2008

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by all-mtr-teg &raquo;</TD></TR><TR><TD CLASS="quote">2 Relay Sockets have terminals that look like this 97 GSR
Left
[A B]
[C D]

Right
[A B]
[C D]

Left socket,
A-C no voltage
B-D 13.9 volts
A-ground on frame, no voltage
B- ground on frame, 13.9 volts

Right Socket,
A-C no voltage
B-D 14.2 volts
A-ground on frame, no voltage
B-ground on frame, 14.2 volts

ALSO, where is the A/C diode and how do you test that?


Hope this makes sense


Modified by all-mtr-teg at 9:14 PM 2/25/2008</TD></TR></TABLE>
Help please

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by all-mtr-teg &raquo;</TD></TR><TR><TD CLASS="quote">
B- ground on frame, 13.9 volts

</TD></TR></TABLE>
I'm puzzled by this. Is it grounded or have voltage?

 

Mutlimeter red probe is connected to terminal B and the black probe is connected to the frame.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by all-mtr-teg &raquo;</TD></TR><TR><TD CLASS="quote">Mutlimeter red probe is connected to terminal B and the black probe is connected to the frame.</TD></TR></TABLE>
Ahhh ok. So now we know you have the needed voltage supplies.

Now with the engine running and the a/c switch on measure for voltage between terminals A+B. Then between terminals C+D.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by all-mtr-teg &raquo;</TD></TR><TR><TD CLASS="quote">Mutlimeter red probe is connected to terminal B and the black probe is connected to the frame.</TD></TR></TABLE>
Ahhh ok. So now we know you have the needed voltage supplies.

Now with the engine running and the a/c switch on measure for voltage between terminals A+B. Then between terminals C+D. That way we will know if the relay is getting a ground signal or not.

 

Alright, I'll check it out tonight. Also, is it true the condensor fan won't turn on if freon is low, I thought that only applied to the a/c clutch?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chiovnidca &raquo;</TD></TR><TR><TD CLASS="quote">
Ahhh ok. So now we know you have the needed voltage supplies.

Now with the engine running and the a/c switch on measure for voltage between terminals A+B. Then between terminals C+D. That way we will know if the relay is getting a ground signal or not.</TD></TR></TABLE>

Okay, A+B = no voltage, C+D = no voltage