My AC will blow cold air for a bit, then ambient for a long time, then cold, then will just blow ambient. I had it recharged, so the pressure should be fine. Is there a switch that may be bad? The compressor seems to come on and off a lot as well.
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Any AC experts out there?
- Thread starter deez
- Start date
Barnes
Well-known member
Did you recharge with r-134a?
Check on your logger whether the ECU is seeing the A/C Clutch signal coming in. This is easiest to view with Pocketlogger or TMO. Search for a couple recent A/C posts, where I showed diagrams of how the A/C switch signal (+12 volts) has to go through the HIGH/LOW pressure switch and then the thermoswitch on top of the thermostat, which is usually the problem.
+1 to Jeff's suggestions.
Also when it was recharged what were the high and low pressure gauges reading? If the High goes higher and Low goes lower when RPM's go up the expansion valve is likely toast. It keeps the system pressure constant, regardless of refrigerant charge or temps. It would also explain the compressor cycling ( high pressure triggers the switch, then once pressure drops the switch closes again ).
Also when it was recharged what were the high and low pressure gauges reading? If the High goes higher and Low goes lower when RPM's go up the expansion valve is likely toast. It keeps the system pressure constant, regardless of refrigerant charge or temps. It would also explain the compressor cycling ( high pressure triggers the switch, then once pressure drops the switch closes again ).
Barnes
Well-known member
What Ktmrider said. Hooking it up to a manifold gauge would probably help diagnose the problem quickly.
monitor the pressure with gauges make sure the condensor fan is on to keep the pressure down while sitting still, if that fan konked out the compressor will shut down until the pressure drops. Or it might keep cool when driving from the fresh air going through the condensor and get warm at idle even though its charged properly.
Quoting deez:
Can that info be viewed with MMCD logger? I can't say I've seen that option on there
Its not as easy on MMcD. This is from the v1.8 thread on 3si.org:
Flag 02 status bits
A - Air conditioning relay
F - Fuel pump relay
B - Boost related ???
Flag 00 status bits
T - TDC sensor
S - Power Steering Pressure SW
A - AC switch
N - Neutral
I - Idle switch
Can that info be viewed with MMCD logger? I can't say I've seen that option on there
Its not as easy on MMcD. This is from the v1.8 thread on 3si.org:
Flag 02 status bits
A - Air conditioning relay
F - Fuel pump relay
B - Boost related ???
Flag 00 status bits
T - TDC sensor
S - Power Steering Pressure SW
A - AC switch
N - Neutral
I - Idle switch
