Chris Ryan

Can anyone direct me to a previous post or answer a question about the A/C system in a 1984 Carrera ? When I turn on the A/C nothing happens - no blower, no compressor clutch engagement, etc. I just replaced the receiver & had the system evacuated and charged - seems to be holding pressure. If I jumper power to the A/C relay in the fuse box, The system turns on and seems to work fine - blows cold air, etc. Is there another relay in the system upstream of the A/C relay in the fuse panel ? Where is the low pressure cutoff switch located ?

Thanks

Chris Ryan
Harvard, MA
1984 Carrera

scottb

The 84 did not come with a factory low pressure cut-off switch. It's possible a PO put one in, however. Look at the hoses near the compressor. You may find a low-pressure cut-off switch there. But, since you're able to get the system to work with a jumper, and since you think the system is holding pressure, my strong hunch is that the low-pressure switch (if you have one) is fine and that the system is fully charged.

It seems to me that if you can jump power to the a/c relay and get the system to fire, you probably have a bad switch inside the car. Have you checked that yet? That's probably the first place to start.

Scott

Richard C2S

Chris,

I have the same problem. But haven't jumpered anything. I suspect its the switch in the console. Please let me know how you proceed. Thanks.
kessler993@msn.com

Richard

Chris Ryan

Scott and Richard

Thanks for the replies. I see no (potential) LP switch near any of the hose fittings; I see no voltage on any of the terminals on either the blower switch or the two electrical connections (green wires) connected to the temp control switch. I did find a blown fuse in a an in-line holder near the IGN switch and replaced it but that did nothing. Any other suggestions ?

Just in case this has any bearing on the situation ... Before I had the system charged, I had just replaced the receiver/dryer because it had a pin hole leak (when we first tried to re-charge the system) so it was open to atmosphere prior to repair and putting the current charge in. Funny thing is that even before I discovered the leak in the receiver, the system worked fine (electrically). Turn the fan switch, got the blower and the compressor clutch engaged. This electrical problem only happened after the new receiver was put in.

scottb

It sounds like you have an unhappy coincidence...it's not likely replacing the receiver/dryer had anything to do with your problem. Can you run a wire temporarily (for testing purposes) from the fused side of the a/c fuse to the back of the switch? You might have something as simple as a fried wire. Also, can you temporarily swap another relay? Try both of these tactics to see if you get anywhere.

Also, the switches are known to go bad. Pelican might have the OEM switch. www.griffiths.com has a newer, high tech switch. If you're going to pull the fader switch between the a/c switches, be prepared for the housing in the console to break (they're very flimsy). Pelican, I think, sells a plate that you can glue over the old switch area, covering up the slot for the fader switch (assuming you've upgraded the radio and are no longer using that switch).

Also, I assume you're testing with the engine running, right?

Keep us posted.

Chris Ryan

Yes, engine is on. I'll try the jumper wire - good idea. Should I jumper to one of the leads on the temp control switch or on the fan switch ? Do you know the routing of wiring between the fuse box/relay area in the front trunk ? Are there any other relays controlling the A/C system other than the round red one in the main fuse/relay box up front ?

Could something have become disconnected under the dash ? I did recently install a new stereo - perhaps something got dislodged - I thought I was being careful to only touch audio related things but things happen ...

Thanks again in advance ...

scottb

Anything's possible. Have you looked at the back of the switch? Are all the wires connected?

I'm not intimately familiar with the wiring there, but you might go over to www.pelicanparts.com. They have electrical wiring online.

I'd connect the jumper to the fan switch.

Chris Ryan

Scott

Thanks for reminding me to (re)check pelican parts. They showed an A/C relay (different than the one in the fuse box). While the person I spoke with did not know where it was located, at least he gave me reason to believe it actually existed. Later, I got an email from one of their techs suggesting I look in the smugglers box and there it was - AND it tests bad. So new relay on the way and the mystery is solved. Thanks for your help !

wheatdog

Chris,
Where is the smuggler's box located? I need to check my relay as well. My symptoms are the same as yours.

Chris Ryan

In the front (trunk). Peel back the carpeting and there is a "trap door" with a small catch on it - between the windshield and the gas tank. Open it and it has access to the steering coupling, as well as the A/C blower, some of the A/C lines & fittings, and the "magic" relay.