dr76

Didn't know if this should go into "Engine Swap", "Electronics", "Cooling" or what, so here it is...

Has anybody retrofitted an LT1 engine into an earlier non-FI car and have A/C?

I put a '95 LT1/4L60e into a '76 Vette a few years ago and really want to get the A/C up and running (in S. FL. summer has begun!)

I had to use the F-Body PCM (wiring harness required it), but have the Y-body program in it. I believe I will be making use of the following wires: (letter = PCM connector, number = pin #)

B1 = A/C request signal
D8 = A/C Clutch Relay Control
B21 = A/C clutch status
D12 = A/C refrigerant press. sensor signal
B16 = A/C refrigerant press. sensor signal ground (in use...will "T" into)
B29 = 5 Volt reference (in use...will "T" into)

I'm not going to use D24 (A/C evaporator temp. sensor signal) and will turn off this function w/ PCM tuning software so it does not set a DTC (data trouble code), but want the A/C and PCM to "communicate" as much as possible to how they are supposed to.

Does the following make sense?

1) Connect the wire from my center console A/C switch that USED to go to the pressure switch along the inner pass-side fender TO the "B1" (A/C Request Signal) wire.

2) Connect "D8" (A/C Clutch Relay Control) to my A/C Clutch Relay

3) Connect the "positive" wire from the Clutch Relay to the A/C Clutch on the compressor AND to "B21" (A/C Clutch status)

4) Connect "D12" (A/C Refrig. Press. sensor signal), "B16" (A/C sensor ground) AND "B29" (5-volt ref.) to the appropriate locations on the A/C Refrig. Pressure Sensor.

* Is the A/C Pressure Sensor part of the "receiver/drier"? I cannot locate a part number.

Will my 2nd fan automatically turn on when A/C is on and will the A/C clutch disengage when in WOT or is there more wiring involved?

I made all these assumptions from Figure A-6 - PCM Wiring Diagram on Page 6E3-A-10 of the Y-Body '95 Service Manual (Book 2). [very similar to the same figure on page 6E3-A-8 in the F-Body Service Manual]

Other info:

I'll be using the compressor that came w/ the '95LT1 (Nippendenso) since it's already mounted and uses the serpentine belt...

Currently, that's the only '95 component I have. The condensor and evaporator core are for the '76 and are new (still have the end plugs installed to keep moisture out until connections are made)

Parts I'm not sure about: What receiver/drier do I get? Does it have the refrigerant pressure switch built-in? What about the orifice tube...where exactly is that? Is it something I need to buy or is it part of one of the components? Also, is the A/C clutch relay any different from the typical 5-post relays used elsewhere...like the fan relays (for example)?

Thanks for any input...I'm sweatin' bullets down here!

dr76

When did everyone get so shy?

Looking forward to your responses