The AC, along with the electric choke and alternator quit working on my 1984 5.0 due to the AC WOT cut off switch and corresponding pigtail wiring basically disintegrating due to it being on top of the manifold. It is bolted to the manifold by the left side of the Holley carb. There is also a controller for the idle speed when the AC is turned on. I was able to create a jumper on the plug on the wiring for the cutoff and get the alternator working again. Why Ford would make a switch that if it fails not only affects the AC but charging and electric choke? Would appreciate any suggestions, as this switch is obsolete: #E4PZ-9S520A. Any suggestions for a work around as this switch seems to be very difficult to find. If anyone knows a source for it would be also very helpful.
Electrical AC not working on 1984 5.0 with holley carb
- Thread starter CharlieGP
- Start date
Not sure if my 83 wiring is much different than your 84, but I had to rewire most of the looms that went over the manifold too...
Most if not all of the system you described is unavailable so I removed all of it from my car, including the tad/tab and all of its vacuum operated lines wth it.. What an engineering nightmare that is.....
The stock electric choke comes off of the stator stud on the alternator so I want to say if your alternator stopped working it probably affected your choke...
I honestly don't think your switch caused this problem but maybe some " disintegrating" wiring did....
Recommend you buy this Factory manual if you don't have one... It will have the system you are working on printed out in an easy format to follow.. A must have manual in my opinion.....
https://www.ebay.com/itm/3152381011...pid=5335821607&customid=&toolid=10001&mkevt=1
Most if not all of the system you described is unavailable so I removed all of it from my car, including the tad/tab and all of its vacuum operated lines wth it.. What an engineering nightmare that is.....
The stock electric choke comes off of the stator stud on the alternator so I want to say if your alternator stopped working it probably affected your choke...
I honestly don't think your switch caused this problem but maybe some " disintegrating" wiring did....
Recommend you buy this Factory manual if you don't have one... It will have the system you are working on printed out in an easy format to follow.. A must have manual in my opinion.....
https://www.ebay.com/itm/3152381011...pid=5335821607&customid=&toolid=10001&mkevt=1
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Thanks for the input. In my case the AC stopped working last fall even though it had a charge still in it. The choke and charging system began operating intermittently this spring before going off line altogether. Fortunately where I am on the coast of Nova Scotia the weather seldom gets hot enough to require AC and the car is a ragtop.
The garage where I sometimes take the car specializes in older vehicles and suggested that due to deterioration the wiring may need replacement due to age. I tried to find a replacement harness but no one seems to make one for Foxbodies. So may end up doing what you have done.
The choke is still inoperative even though the car is charging with a jumper wire, so I've blocked it open. To get it operational for now I plan to replace the 7 volt thermostat on the factory carb with a 12 volt, and wire it to an ignition source on the fuse panel. Others have done this after replacing the original carb and needing 12V to be compatible with the new carb. No sure why Ford chose to run 7V to the carb? Looks like I may have a winter project in the making.
The garage where I sometimes take the car specializes in older vehicles and suggested that due to deterioration the wiring may need replacement due to age. I tried to find a replacement harness but no one seems to make one for Foxbodies. So may end up doing what you have done.
The choke is still inoperative even though the car is charging with a jumper wire, so I've blocked it open. To get it operational for now I plan to replace the 7 volt thermostat on the factory carb with a 12 volt, and wire it to an ignition source on the fuse panel. Others have done this after replacing the original carb and needing 12V to be compatible with the new carb. No sure why Ford chose to run 7V to the carb? Looks like I may have a winter project in the making.
Charlie, there is nothing on the top of an 84 5.0 4barrel engine that has anything to do with engine charging.
All the wires run off the passenger side fender well , and this year uses an External Voltage regulator that’s mounted there as well.
I also have absolutely no idea why Ford used a 7 Volt choke either.
The A/C wire the powers the throttle kicker and the A:C WOT switch are all together as noted… that switch is normally hot, so you need splice those wires together in order to trigger the the A/C. You will lose the WOT cut off unfortunately.
Check a wiring diagram and you will see that the switch cuts power to the compressor at full throttle.
I run a Holley 570CFM with a manual choke… I rarely need it , as I drive this car in cold weather.
Scott
All the wires run off the passenger side fender well , and this year uses an External Voltage regulator that’s mounted there as well.
I also have absolutely no idea why Ford used a 7 Volt choke either.
The A/C wire the powers the throttle kicker and the A:C WOT switch are all together as noted… that switch is normally hot, so you need splice those wires together in order to trigger the the A/C. You will lose the WOT cut off unfortunately.
Check a wiring diagram and you will see that the switch cuts power to the compressor at full throttle.
I run a Holley 570CFM with a manual choke… I rarely need it , as I drive this car in cold weather.
Scott
