86 bronco II a/c compressor problems...help!

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hi all....first off, my mechanical skills are pretty fair, but my electrical skills are pretty rudimentary. i have a 86 ford bronco II xlt with a 2.9L, 4x4, automatic with electric 4wd and factory a/c with the ford compressor. it is original except the paint job and the wheels and tires and stero. i've owned it since '90 and it has about 190,000 on it. i have a problem with the a/c. first some history....about 8/9 years ago, i had a leak in the evaporator and i lost all of the charge and all of the oil with it. the compressor siezed up and fried. i replaced the compressor, the evaporator, the orifice tube and the accumulator/drier....charged with about 7 to 8 ounces of oil, evacuated the system and re-charged with fresh r-12. good to go untill the present. have since developed a leak in the condensor and one of the hoses (the liquid line). once again, lost the oil and r-12 charge and fried the compressor (lucky me). i have now replaced the condensor, all of the hoses/lines (the suction, discharge and liquid lines), the accumulator/drier and bought and installed a rebuilt ford compressor from auto zone. have once again, evacuated the system and recharged with oil and fresh r-12 (i have a stash of r-12 i've been saving for years just for this truck). now....here is where i'm running into trouble. i went to start the truck and fire up the a/c....nothing. i checked the fuse....it was blown so i changed it. still nothing....i didn't see anything else that would hold out the compressor except the pressure switch (the pressure switch that cycles the compressor mounted on the accumulator)....so i replaced the pressure switch. still nothing.....that is the extent of my investigation. i'm at a loss as to where to look next...or how to proceed from here. did i buy a dud of a compressor from auto zone?...if so, how do i check it to be sure. what else can i do/look for. thanks in advance for any help i can get from you guys....thanks, bf. :thumbs:

posted by  bronco II guy

Hi , first thing is do you have power at the pressure switch ?power at the switch in the dash? you can jump the plug at the pressure switch and see if the clutch kicks in if there is power there,that will tell you if the clutch is good or not, now if you had a blown fuse ,what blew it check wiring , see if there is a bad spot or bare spot in the wiring harness around the comp. any way check for power with a test light first not sure might be a relay in the system if so check it for power, good luck Slim

posted by  Slimone

hi slim one.....thanks for the help. i did some more checking on this thing. it has a relay, but it is in the fan circuit and not the a/c circuit. the a/c circuit only has the push button on/off switch (with a on light) for the compressor, the pressure switch and then the compressor. as it turned out, that brand new pressure switch i bought was a dud. i had power to the switch, but when i hooked everything up, i didn't get any power to the compressor. so....back to autozone i went and bought another 11.99 pressure switch. insto, presto....power to the compressor. i am now chillin' while driving once again. again, thanks for the input and the help, bf. :wink2:

posted by  bronco II guy

I have been searching the web for help on my '86 B2 a/c problem but with no luck and then I found this tread. Soooo close!
I need help finding what causes the cut-out relay to engage supplying power to the pressure switch. I have power to the relay all the way through the switch to the relay but I am not getting a voltage to the relay to put power to the clutch and the pressure switch. Can someone tell me where this switched voltage comes from? When I touch 12V to one side of the coil on the relay it engages the clutch and the ac works until the pressure switch kicks out then I need to apply 12V again to make it cycle. Applying a constant 12V to the coil on the relay will allow the system to run normally and be controlled by the a/c switch on the dash but it keeps the relay energized all the time. I know this not a common problem but if you can direct me or provide a diagram for this part of the system i would be greateful. Thanks

posted by  BigHornMan

you might want to start a new thread:2cents:

posted by  dvdrose18

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