A/C not working? help! | Ford Explorer Forums - Serious Explorations

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A/C not working? help!

Hossexplorer

Well-Known Member
Joined
September 30, 2008
Messages
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City, State
Baker City, OR.
Year, Model & Trim Level
'93 XLT
I recently finished a 5.0 swap in my 93 Explorer. Now, I can't seem to get the Air Conditioner to work. ALL components are brand new and from the factory 4.0, so I didn't change anything in the A/C system.

The Fan blows inside and the A/C light turns on but is not cold. If I run test leads from the compressor to the battery directly, the A/C blows COLD inside the cab. But, the compressor will not kick on from the switch inside.

Any ideas? Thanks!
 



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There is a pressure switch in the system, I believe it is located near the accumulator/blower box area. It only allows the compressor to turn on if there is adequate pressure in the system, since the oil in the refrigerant is what lubricates the compressor. If the system was working previously, I would check wiring. not sure how to check switch. I would guess the switch is normally open, so pulling the connector and shorting the two harness wires should turn on the compressor also, which would probably indicate a bad switch.
The fact that it blows cold air seems to indicate you have enough refrigerant, but I'd be careful, and try to get a pressure check on the system.
 






There is a pressure switch in the system, I believe it is located near the accumulator/blower box area. It only allows the compressor to turn on if there is adequate pressure in the system, since the oil in the refrigerant is what lubricates the compressor. If the system was working previously, I would check wiring. not sure how to check switch. I would guess the switch is normally open, so pulling the connector and shorting the two harness wires should turn on the compressor also, which would probably indicate a bad switch.
The fact that it blows cold air seems to indicate you have enough refrigerant, but I'd be careful, and try to get a pressure check on the system.

The refrigerant/oil is new and at the appropriate pressure. I will pull the pressure switch connector and try that. Thanks
 






X2 on the pressure switch. If the pressure switch checks out and it's sending the right signal back for the ac to run, and if then your still not getting power at the connector to the compressor, then you'll have to trace the wires.
 






There is also the Wide Open Throttle cut out.

There is a relay in the power distribution block labeled WOT, with the 5.0 swap the wiring from the throttle position sensor is absent.

You will need to bypass the WOT relay.
 






There is also the Wide Open Throttle cut out.

There is a relay in the power distribution block labeled WOT, with the 5.0 swap the wiring from the throttle position sensor is absent.

You will need to bypass the WOT relay.

Ahh! I was wondering if something about the swap could have caused this! Thank you!
 






When the "stock" TPS reaches 80% the A/C clutch is disengaged by the WOT relay. If you bypass just keep in mind NO redlining the engine with the A/C on! keep it under 3000 RPM when running the A/C
 






If you get the pin-out chart for the 5.0 PCM you can bodge in a jumper to re-establish the wide open throttle function.
 






Ok, still need help. I finally got around to working on the AC. Here's the deal. I jumped these two terminals in the AC/WOT relay and the AC compressor kicked on!
KIMG1266.jpg


But only for 2 second bursts. ON, OFF, ON, OFF. So, I tested the signal with a test light at the pressure switch. It gets signal then loses it. Does that mean my system is low on refrigerant? Also, do I have a bad relay?
 






sounds like not enough Freon or your pressure switch on the accumulator is bad
roscoe
 






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