Hi team, my wife & I have an 82 Indy Pace car which originally had AC but had since had a later model 305 fitted (serpentine belt) originally v belt. I need to identify the wiring I need to connect all AC items under the hood (bonnet).
Can you please assist me with this?

 

Is the engine harness from the car? Or from the newer engine?

 

pretty sure the loom is from the car

 

I'm pretty sure under the hood wiring for the a/c is just the pressure switch and the compressor plug. I don't have access to wiring schematics until Monday when i go back to work to verify that. Looking at my car the compressor plug is a flat 2 prong with a Resistor between the power and ground. And the press switch is a parallel 2 prong on the accumulator.

 

 

That looks to be everything for this Car if it was Built with the Carbed 305.

The CrossFire 305 Cars also had a Relay and a Circuit from the PCM.

 

Sorry guys, not trying to hijack a thread, but I’m not sure who else better to ask since I’m dealing with a very similar issue. PO of my car cut the wires going to the compressor. Now that I see your photos of the black and green wires with the resistor between…… where do those wires trace back to? I’m sure I’ll find them cut in the loom somewhere hopefully, but are they on the drivers side bulkhead or passenger side? Will they still be black and green when traced back?

 

I can't really tell what direction things are going so i will try to remember to grab a wiring diagram tomorrow at work.
what I did notice is another connector on the back of the compressor. Using an ohm meter on mine I noticed the black wire behind the compressor clutch is ground. The green goes to the connector on the back of the compressor and the other side of it is light blue black. That goes to the pressure switch on the dryer.
if I were to guess with this primitive wiring, the switch on the back of the compressor is a high pressure switch that is closed until high pressure opens it, the one on the dryer is normally closed when freon is present and the relay turns the whole thing on. So basically voltage is passing through each component if each one has the needs met to be in the closed position.
use a fused jumper wire from battery positive to the green wire on the clutch, you should hear the clutch engage.
if so move to the blue black wire on the back of the compressor and look for the same results.
if so move to the green wire on the blue wire on the dryer. Then the green wire. Testing the blue wire will check the circuit to that point, check the green wire will do the same but include the pass-through that low pressure freon triggers.

 

 

Awesome! Thankyou!

 

The Component that is crimped between the Two Terminals of the Electrical Connector (in the Image Above)...
Is actually a Diode (Not a Resistor).

Similarly, a Diode or Resistor is often used internally or externally on the Coil of Relays...
But in this situation it is a Reverse-Biased Diode.

Should you require one/ some...
Diodes with identical specifications to the OEM Component can be purchased from Mouser.com
Part Number: 1N4004-T (from Diodes Incorporated).

The Legs of the Diode should never be exposed (as in the Image above) and should be properly insulated/ protected with Heat-Shrink Tubing or a Boot.

 

mostly exactly as i described

 

the split going over to the ecm is more than likely a 12v on signal fed from the compressor power wire into the ecm to let it know to raise the idle. So if you don't have that it's not that big of a deal for now, just splice it in before you plan on driving with the ac on because it will probably die while you're waiting at red lights.

 

Like I said, the wiring is very primitive compared to modern cars so it shouldn't be that big of a deal to correct. The diagram doesn't show if it goes through the passenger side but more than likely it does.

 

From the car