need help to put back my a/c in my 75 t/a
 

my car is a 1975 t/a were the a/c was removed way back , try to put it back in . need to know this
the compressor has a wire harness with a black ground and a green wire ,were does the green wire hook up to

also there seems to be a black small vac hose that comes out from the firewall , were does that go

Black wire is a ground, usually hooks up under the bolt securing compressor to bracket.
Dark green wire is essentially the live wire from the AC controls, which runs via pressure switch on the AC drier.
There is sometimes a light green wire that runs to the carb solenoid to bump the idle up when AC is turned on. It may be a separate harness on early models.
Small black vacuum hose is likely also for heater box controls. It has one main vacuum source and the control changes where it is direct to.

have two of these compressor to a/c jumper harness but someone cut of some of the connectors , anyone have a photo of one that i can compare to

Not sure this helps much for a '75 400, this is from a '77-79.

https://farm8.staticflickr.com/7908/...e60d1f5c_b.jpg403 Firebird AC compressor loom idle solenoid by Aus78Formula, on Flickr

Likewise, here's similar era chev but they've jumpered the wire that goes to the blower motor onto same setup.

https://www.camarocentral.com/1973_1..._p/wir-265.htm

ok that is great i have one like this .the other one has a thermal limiter on it would that be for my 75

Ignore all that, 75 used the combined compressor and heater harness as one including the thermal limiter.
Do you not have electrical diagrams or workshop manuals for it? Haven't saved every second photo you saw online thinking it might be of use one day?
8 days later no one with a 75 has bothered to chime in.

https://www.firebirdcentral.com/Prod...Code=HTR%2D166

https://www.firebirdcentral.com/product_p/wir-2025.htm

sorry have no manuals , was hoping to get info here

Wire and hose pages.

Good one, saved.

very good and thanks . only nee to know now ,were does the brown wire from the thermal limiter connect to

It goes into the wiring harness on the driver's side. Pictures are of '74s.

Great thanks. Looks like the po cut it off ,hope I can find it

is the brown wire the power source

I never checked. I'll try and pull a book if no one else can answer.

any one can help me on this brown wire