Need A/c Help!

[Semaj Shelton]

Please help! I have a 1982 mustang Gt with factory air. When the a/c is engaged, the compressor won't kick on. If I use a jumper wire from the battrey to the compressor it kicks on and blows super cold air. I have a new low pressure switch. When I tried to jump the terminal on the low pressure switch it should kick on the compressor,but has no power. I checked the inside switch......when put in the a/c position it does energize the a/c idle solenoid. Refrigerant is not low. I do have some wires not connected to anything.

 

[jrichker]

Your car is old enough that most of the documentation is hard to find.
If you haven't bought a Chilton repair manual from the local Auto Parts store, this is the time to get out your wallet...

The likely culprit is the A/C WOT relay which shuts off the A/C compressor when you go to full throttle.

The diagram below isn't a match for your car but it may be of some use.

The following are diagrams courtesy of Tmoss & Stang&2birds

Fuel, alternator, A/C and ignition wiring

HVAC vacuum diagram

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring; http://www.veryuseful.com/mustang/tech/engine/ Everyone should bookmark this site.


TFI module wiring for 94-95 Mustang GT
http://www.veryuseful.com/mustang/tech/engine/images/Mustang-94-95-IgnitionControlModule.gif

Complete computer, actuator & sensor wiring diagram for 91-93 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/91-93_5.0_EEC_Wiring_Diagram.gif

Complete computer, actuator & sensor wiring diagram for 88-90 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

Fuel, alternator, A/C and ignition wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

O2 sensor wiring harness
http://www.veryuseful.com/mustang/tech/engine/images/mustangO2Harness.gif

Vacuum diagram 89-93 Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg

HVAC vacuum diagram
http://www.veryuseful.com/mustang/tech/engine/images/Mustang_AC_heat_vacuum_controls.gif

TFI module differences & pin out
http://www.veryuseful.com/mustang/tech/engine/images/TFI_5.0_comparison.gif

Fuse box layout
http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif

Mustang 5.0 Lights and Radio schematic, by TMoss:
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxLights-Radio_diag.gif

87-92 power window wiring
http://www.veryuseful.com/mustang/tech/engine/images/mustang87-92 PowerWindowWiring.gif

93 power window wiring
http://www.veryuseful.com/mustang/tech/engine/images/mustang93PowerWindows.gif

T5 Cutaway showing T5 internal parts
http://www.veryuseful.com/mustang/tech/engine/images/5_Speed_Cutaway_Illustrated.jpg

Visual comparison of the Ford Fuel Injectors, picture by TMoss:
http://www.veryuseful.com/mustang/tech/engine/images/Ford_Injector_Guide.jpg

Convertible top motor wiring http://www.veryuseful.com/mustang/tech/engine/images/mustang88VertTopMotorCkt.gif

Engine mounted fuel injector harness
http://www.veryuseful.com/mustang/tech/engine/images/mustangEngineHarness.gif

Location of the TPS, IAB, and the 10-pin connectors on a 5.0, picture by TMoss:
http://www.veryuseful.com/mustang/tech/engine/images/TPS_IAB_Pic.jpg

Starter circuit
http://forums.stangnet.com/attachment.php?attachmentid=21328&d=1080916057

Alternator diagram for 94-95 Mustangs.
http://www.veryuseful.com/mustang/tech/engine/images/Mustang-94-95-Alt.gif

 

[Semaj Shelton]

Does a 1982 4 speed manual have a WOT relay? I found this diagram that shows a/c relay.....I just can't find its location

 

[Mustang5L5]

Pass side fender on the EFI cars. Unsure if similar on older models

 

[General karthief]

https://www.stangnet.com/mustang-forums/attachments/img_0361-jpg.181331/
See if this link works

 

[jrichker]

Does a 1982 4 speed manual have a WOT relay? I found this diagram that shows a/c relay.....I just can't find its location

The relay is probably on a page before the one you posted.

The Ford diagrams usually give you a letter row and number column when a circuit goes from one page to the next. The number column is useful in finding the page, since the columns are numbered sequentially. Unfortunately your doesn't seem to look like that.

I looked at one of the old Hanes manuals and it seems that the body wiring was pretty much the same from 81-86. With that in mind here is a free resource that you can download an 86 EVTM wiring and vacuum troubleshooting manual. I checked the link and it is still alive and seems to be working.

See http://slantnosefox.com/picturehosting/jeremy/86 electrical & vacuum troubleshooting manual.zip you can download the whole set of electrical troubleshooting and diagrams for an 86 Mustang courtesy of Jeremy, AKA V8only.
It is a big 61 MB download that you get to unzip and save on your computer. It may take some time to download it, but the results are worth the effort. The GIF numbers correspond to the page numbers in the table of contents, which makes it easier to find what you want.