ptmays

Ok haha my first post, I've had my 95 Trans Am LT1 for 4 weeks now and still learning about the car but I'm hitting a few road blocks.

One of the previous owners partly deleted the AC and I want to put it back.

They removed all the lines, dryer, condenser, and clipped the compressor pigtail.

I think I can find all these parts on ebay...

Ive found the wire for the pressure sensor, the one in this picture linked below.

http://shbox.com/1/refrigerant_sensor.jpg

What I have not found is a wire for a 2nd sensor, I know typically there is on the high side and low side. This diagram below shows one, did they have the 2nd one in 95? If so can someone send me pics of where those wires come out of the harness.

http://shbox.com/1/ac_system.jpg

Ive never messed with an AC system much any advice from those with more experience and can anyone post me some pictures of how everything is supposed to fit google has been coming up a little short for me.

ptmays

Links to the parts I'm considering ordering.

Evaporator to Dryer Line

Condenser to Dryer Line

Compressor Lines

Compressor Pigtail

Dryer

Havent really looked at condensers yet

Injuneer

Only the one pressure sensor, and an evaporator temp sensor.

http://shbox.com/1/hvac_compressor_control.jpg

While the plumbing schematic shows a second sensor (items 36-39), as you can see from Shoebox's photo, that sensor port does not exist.

95 wiring harness:

1995 Z28 A4 Engine Harness

ptmays

Hi Injuneer thanks for confirming the lack of the 2nd pressure sensor, that diagram has been driving me crazy.

Where is the evaporator temp sensor located? Is that up under the dash?

shoebox

That temp sensor is right on the evaporator coil (yes, under the dash). I doubt someone went to the trouble to remove it.

ptmays

Anyone have any thought on the parts list Ive got above, any yay or nay on those? And any pit falls I need to look out for when reinstalling all this?

Injuneer

Don't overlook the diode in the wiring at the compressor cutch. Look the control diagram over very carefully. It even shows the temp sensor is "inserted in evaporator".

rngilliland

I would replace the compressor and condenser. Since someone removed the parts you listed the A/C probably wasn't working anyway. You will need to flush the system and it's difficult or impossible to flush the condenser. I would replace the expansion valve too. Most of the parts are available from Rock Auto. You can get some of the parts you listed new from them for about the same price as used.

After you assemble the system you will need to take it to a shop to have it evacuated and charged. If you have access to a vacuum pump and gauges you can do it yourself. It takes 2lb of R134. Three 12oz cans works out about right by the time you lose a little. Be sure you use the correct amount and type of oil. Some compressors come with some oil already in them. The best thing to do is drain that oil and then put the correct amount in before evacuating the system. You can use the oil you drained out. The oil should be spread around, not just put in the compressor. You need 8oz of PAG oil for an empty system. I think the viscosity is 150 but I'm not certain.

You will need to reset the PCM to get the compressor to run the first time. Just pull the PCM fuse for a few seconds. If you don't have a factory manual there are some online but I don't know the links. The manual has all the information you need.

ptmays

Any thoughts on finding the correct diode, i saw that in the diagram but the pigtails dont have it on them and its been cut off mine.

Yeah good call on replacing the compressor, maybe the expansion valve also. At that point its a 90% new system, as long is there isnt wiring issues I should be good.