'88 E250 A/C breaker, fuse location.
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Joined: Jun 2014
Posts: 33
From: Tucson, AZ
'88 E250 A/C breaker, fuse location.
Hello Again! I'm troubleshootinh my A/C system. Some of my vehicle's vacuum tubing and electrical may have been disabled. I've been at work restoring it. I found a wiring harness connector, behind the AMP meter location with nothing attached. Is it possible a relay should be there to get the A/C clutch to engage. Is ther anything else I should be searching for? I did find a breaker (assumed) on the fuse panel and it check out. My gut feeling is there is another place along the wiring harness or fire wall with a relay or circuit breaker missing/damaged/broken. Thought?
Thank you for you help!
Ps, is a warmed up hight idle an indication of Idle Air control failure? Stopping the engine and restarting clears the fast idle about 1200-1500 RPM's
BilldarrAZ
Thank you for you help!
Ps, is a warmed up hight idle an indication of Idle Air control failure? Stopping the engine and restarting clears the fast idle about 1200-1500 RPM's
BilldarrAZ
Last edited by BilldarrAZ; Sep 24, 2014 at 02:34 PM.
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Joined: Jun 2010
Posts: 16,584
Hi Bill,
Power to the compressor clutch comes from the heater mode selector on the dash.
It goes through a normally closed clutch cycling switch, mounted on the accumulator, with a light green/purple wire from the selector to the cycling switch and from the cycling switch through a black wire to the compressor clutch assy. This circuit is powered by a fuse only. ( #9 ) controlled by ign switch.
There is a blower motor hi speed relay just in front of the starter relay at the R/F headlight area. That relay is active only when blower hi speed is selected.
It might be a good idea to confirm that you have power to the selector switch on the selector control assy. If the blower motor operates you probably have power there. The thing to do next would be to see if you are getting power to the lt grn/purple wire coming out of the selector switch when A/C is selected. If you have power there then confirm you have power to the cycling switch on the accumulator. You can temporarily jump the two terminals on the cycling switch to see if the clutch on the compressor engages. If it does there is a good chance the system is low on refrigerant. Don't run the compressor too long with the terminals jumped. The lo press switch is there to cycle and protect the compressor if the charge is too low.
Let us know what you find.
Power to the compressor clutch comes from the heater mode selector on the dash.
It goes through a normally closed clutch cycling switch, mounted on the accumulator, with a light green/purple wire from the selector to the cycling switch and from the cycling switch through a black wire to the compressor clutch assy. This circuit is powered by a fuse only. ( #9 ) controlled by ign switch.
There is a blower motor hi speed relay just in front of the starter relay at the R/F headlight area. That relay is active only when blower hi speed is selected.
It might be a good idea to confirm that you have power to the selector switch on the selector control assy. If the blower motor operates you probably have power there. The thing to do next would be to see if you are getting power to the lt grn/purple wire coming out of the selector switch when A/C is selected. If you have power there then confirm you have power to the cycling switch on the accumulator. You can temporarily jump the two terminals on the cycling switch to see if the clutch on the compressor engages. If it does there is a good chance the system is low on refrigerant. Don't run the compressor too long with the terminals jumped. The lo press switch is there to cycle and protect the compressor if the charge is too low.
Let us know what you find.
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