'72 A/C thermal limiter ??

[Tom L.]

I've been trying to sort out my A/C wiring on my '72 LS-5. The past has not been kind to the a/c system, all the hoses are gone, the compressor brackets are missing, the compressor came in a box and the wires for the harness have been cut leaving only a few hanging out. As I look through the AIM and witing diagrams I see that there should be a Thermal limiter switch. I don't see the wires, plug, thermal limiter or mounting hole for it. Any help locating it?? A picture would be great. Thanks!!

[Tom L.]

Re: '72 A/C thermal limiter ??

Had a thought today. During the '72 model year there were several changes made that once updated in the AIM are not shom in it. I went back to look at the page, UPC C60 Sheet E1, and there was a change in the drawiung for the A/C harness on 10/4/71, doesn't say what the change was though. My car is an early October build pre-dating the change, any chance that the A/C wiring is the same as late '71 cars and there may not be a thermo limiter in the system??

[Tom L.]

Re: '72 A/C thermal limiter ??

Haven't had any luck here so I checked some other forums and came up with a pic from a small block car. The device above the A/C relay is what I think is the thermal limiter. The pic is unconclusive but is it just plugged into the harness or is it fastened to the evaporator housing?

Additionally, the A/C relay is mounted horizontally beneath the wiper door actuator on my car. Is this correct for an A/C car w/ big block?? There are no unaccounted holes elsewhere on the housing so I'm assuming it is. Thanks!!

Thermal limiter.jpg

[Ed D.]

Re: '72 A/C thermal limiter ??

On my 72 SB with A/C the termal limit is mounted on the red striped hose where it connects to the windshield wiper door vacuum motor

[Jerome P.]

Re: '72 A/C thermal limiter ??

Mine is mounted on my '72 LT1 just as Ed described.

[Tom L.]

Re: '72 A/C thermal limiter ??

Ed and Jerome, is the limiter simply plugged into the harness and taped the way it appears in the pic I posted earlier or is it attached in some way (Screwed, riveted) to the fire wall or evaporator housing?? Thanks!

Tom

[Paul D.]

Re: '72 A/C thermal limiter ??

That which appears to be tape is actually a half round steel spring clip on the harness side plug. It appears to be clipped to a larger piece of harness. On most passenger cars, it was clipped to a metal section of one of the hoses at the compressor. Chip.

[Ed D.]

Re: '72 A/C thermal limiter ??

Tom here is a phot0 of the limit switch mounted. No screws or rivits
Ed





http://s948.photobucket.com/user/ed72vette/media/028.jpg.html?sort=2&o=12

[Tom L.]

Re: '72 A/C thermal limiter ??

Thanks a lot Ed, so I guess it's simply plugged into the harness connector and just hangs, or is the connector secured to something.

Anyone know if the arrangement is the same on big block cars??

[Edward J.]

Re: '72 A/C thermal limiter ??

Tom, I looked at the AIM for 72 and it shows the limiter attached to the metal pipe coming off the back of compressor, My 72 C60, L48 car that's is where mine is attached.

[Tom L.]

Re: '72 A/C thermal limiter ??

Ed, thanks for the info. I re-visited my AIM and I think I understand, correct me if I'm wrong since I don't have any of the components I'm asking about at this point. I've only looked at the parts on vendors web sites and there seems to be a hole for mounting on the limiter, which is also shown in the AIM. Guess that led me to believe it got screwed on somewhere.

From what I now see in the AIM, the "Harness connector" has a clip on it that snaps onto either the discharge or suction line and the limitier is just plugged into the connector, is that correct?? Thanks!

[Edward J.]

Re: '72 A/C thermal limiter ??

Tom, you are correct, the clip goes onto the line with the muffler coming off the back on compressor.

[Tom L.]

Re: '72 A/C thermal limiter ??

Thank you!!

[Jerome P.]

Re: '72 A/C thermal limiter ??

Like you said it just snaps on to the line. Why the hole, your guess is as good as any.

[Terry M.]

Re: '72 A/C thermal limiter ??

Like you said it just snaps on to the line. Why the hole, your guess is as good as any.

That thermal limiter had wide application across all GM model lines. I would guess for some application the hole was used to attach it.