ac issues
#52
03-15-2012 | 02:08 AM
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Open circuit.
The PCM puts a voltage down the brown wire, that passes thru the low pressure switch, to the light green with white trace wire, then to the high pressure switch, to the light green wire, and then off to the control head. When the PCM sees that circuit as 'complete', it trips the relay that actually controls the A/C compressor..... (yeah, needlessly complicated.) Somewhere between the high pressure switch, and the control head, that wire is either broken, or crimped, or just a crummy connection, so you aren't getting the voltage across it that the PCM wants to see to turn on the compressor. So, ya need to follow the light green wire, from the high pressure switch, to the heater control head........ and find the problem spot.
If you just wanna put a toggle on it for now, use the light green wire (that is, AFTER the high pressure switch) to control the circuit. (basically, just a toggle to ground..... switch on, compressor runs like it should, switch off, compressor doesn't run at all.) That way, both switches will ALSO still control the circuit.
The PCM puts a voltage down the brown wire, that passes thru the low pressure switch, to the light green with white trace wire, then to the high pressure switch, to the light green wire, and then off to the control head. When the PCM sees that circuit as 'complete', it trips the relay that actually controls the A/C compressor..... (yeah, needlessly complicated.) Somewhere between the high pressure switch, and the control head, that wire is either broken, or crimped, or just a crummy connection, so you aren't getting the voltage across it that the PCM wants to see to turn on the compressor. So, ya need to follow the light green wire, from the high pressure switch, to the heater control head........ and find the problem spot.
If you just wanna put a toggle on it for now, use the light green wire (that is, AFTER the high pressure switch) to control the circuit. (basically, just a toggle to ground..... switch on, compressor runs like it should, switch off, compressor doesn't run at all.) That way, both switches will ALSO still control the circuit.
Just hanging lose &take the other end I can just ground that piece of wire...so could it have something to do with that? Because it seems like if the wire isnt even making it to the plug&I csn ground it that way then maybe its that pigtail plug?Also is there a way to check th switch on the compressor?
Last edited by cutthroatxxx; 03-15-2012 at 02:13 AM.
#53
03-15-2012 | 09:14 AM
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From: Clayton MI
The reason I suggest using the light green wire, instead of the light green with white trace is, it is AFTER the high pressure switch in the circuit. Grounding the lg/w wire removes the high pressure switch from the circuit, giving the compressor the opportunity to put more pressure into the system than it is rated for........ with predictable results. (which wouldn't be any fun either.....)
You should have 12 volts on the lg wire coming out of the high pressure switch, if you don't, then you have found your problem.
You should have 12 volts on the lg wire coming out of the high pressure switch, if you don't, then you have found your problem.
#54
03-15-2012 | 11:43 AM
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The reason I suggest using the light green wire, instead of the light green with white trace is, it is AFTER the high pressure switch in the circuit. Grounding the lg/w wire removes the high pressure switch from the circuit, giving the compressor the opportunity to put more pressure into the system than it is rated for........ with predictable results. (which wouldn't be any fun either.....)
You should have 12 volts on the lg wire coming out of the high pressure switch, if you don't, then you have found your problem.
You should have 12 volts on the lg wire coming out of the high pressure switch, if you don't, then you have found your problem.
#56
03-15-2012 | 01:27 PM
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#57
03-15-2012 | 01:29 PM
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From: Clayton MI
Try putting a jumper wire in that connector (disconnected from switch), and see if the a/c runs.
#58
03-15-2012 | 01:34 PM
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#59
03-15-2012 | 01:36 PM
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From: Clayton MI
Unplug the connector from the switch, connector has two terminals, use a short piece of wire stuffed into each terminal on the connector. You are basically bypassing the switch.
You can also set your meter to measure resistance, and test resistance across the terminals on the switch, should be near zero...... if it reads really high, that would indicate the switch is open. If pressure in the system is correct, means the switch is bad.
You can also set your meter to measure resistance, and test resistance across the terminals on the switch, should be near zero...... if it reads really high, that would indicate the switch is open. If pressure in the system is correct, means the switch is bad.
#60
03-15-2012 | 02:17 PM
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