[78w72]

As it says -- anybody have a PDF file of it they can share? The GM Firebird service manual on CD has great wiring diagrams, but they cover only non-AC wiring. I'm swapping the instrument panel harness and the engine harness on my '72 base bird (with AC) for a '74 TA (with AC) wiring so I can use the TA's tach/speedo and rally gauges, and I'm also doing an AC delete but want to keep the heater function.

[Squidward]

I have a 72 manual in PDF format. It has the A/C schematic on page 1A-6. If 74 has the POA instead of the VIR (I can't remember when the changeover was), then it is probably identical. Regardless, the controls should be extremely similar. Let me know if you need it.

What section of your manual were you looking in? Section 12 won't have it, but Section 1 has it at least for 72.

[Philg]

Attached is scanned out of my 74 service manual

[78w72]

philg: excellent, that's perfect. thanks.

squidward: what do you mean by "If 74 has the POA instead of the VIR"?

also, does anyone know if the fan speed switch connector on the back of the AC-heater control unit is different between the AC and non-AC cars? I suspect they are, because I think the blower motor resistors are different, but I'm not sure.

[Squidward]

Originally Posted by 78w72

philg: excellent, that's perfect. thanks.

squidward: what do you mean by "If 74 has the POA instead of the VIR"?

also, does anyone know if the fan speed switch connector on the back of the AC-heater control unit is different between the AC and non-AC cars? I suspect they are, because I think the blower motor resistors are different, but I'm not sure.

POA means it has one of these at the evaporator outlet, going into the suction of your compressor:


VIR means it has the thermal expansion valve and POA valve all wrapped up into a single monstrosity at the evap inlet/outlet:



BTW, I sent u a PM.

[78w72]

ok, wasn't sure because all the ac parts have been removed, and I didn't want to overlook something if it was related to the wiring.