There's no hookups for the A/C on my new engine harness? Will it be impossible?

[WH23G3G]

I've already started to buy the new A/C components and install what I can in the engine bay before the motor will be worked on and put back in. As I was going throught my wiring harnesses, I noticed the new engine harness I bought from Year One a couple years ago, has no plug ins for the A/C system. I'm installing everything as close to factory as possible, being there was engine swap before I bought the car, it will never be truly factory, but as made to look like it was is what I'm going for. So will it be an impossible to hook the electrical parts of the A/C system up using my original harness with the new engine harness, without having to splice into to many wires and causing the wiring to be all messy.

[Ghoste]

Do you have to splice in?  Can you get the components you need from an original car and very carefully wire them in alongside the repro harness?

[y3chargerrt]

The a/c wiring harness is a seperate harness. Its taped to the main harness. When I put my Year One main harness in I transfered the a/c harness to my main one. Do you still have you original harness?

[Nacho-RT74]

As stated, on 3rd gens A/C wiring is a separated one from the Underdash harness. The A/C wiring is only linked to teh underdash harness on three points:

-A Black wire with female spade terminal coming from underdash harnes up to A/C switch Plug. This wire feeds the Compressor Clutch system on switch.
-A Green wire with male bullet terminal what plugs on the accesories source on underdash( rubber triple femalke bullet kind, tan color I think ).This one feeds the blower on switch system.
-Two wires up to bulkhead to tranny wiring plug both female spade terminal, one blue what feeds the compressor clutch and one green that feeds the blower.

Note: On 73/74 the wires to bulkhead could it be different. They can go to engine bay throught a grommet on firewall, since seatbelts system use the A/C cavities on bulkhead.


About engine bay area... I think originally the blue wire what feeds the Compressor clutch is taped on engine harness, but never arrives up to bulkhead engine harness plug. It runs on this way:

The blue wire coming from the passenger cab ( tranny plug ) feeds first the valve on dryer. This valve is a gas sensor. When there is gas pressure this valve allows to run the power by another blue wire up to engine harness ( if is untouched ) with a spade terminal plug, close to regulator wiring area I think. From there the blue wire is taped on to engine harness up to compressor clutch.

If the aftermarket engine harness doesn't have the blue wire up to compressor you will have just to run a wire from Dryer valve up to compressor. I'll try to make a diagram.

[Nacho-RT74]

I hope this is easy to understand...

74s sure the A/C  blue/green wires aren't through bulkhead... really is by a firewall grommet. 73s it could be or not. earliers are on this way.

[Nacho-RT74]

Allmost forgett this... don't confuse the Regulator/brushes wires with this ones ... similar colors but notr the same.