awilli6

87 auto with 114k on the clock. AC was rigged to blow cold all the time but over time began to blow cold some time. I had to turn off AC for 10-15 minutes and it would begin cooling again.

Posted question on here, freeze switch & add freon was the answer. Changed freeze switch (broke of about 2 in of metal line that goes into firewall. While inserting, I ran into resistance that eventually led to a broken part.

2 questions:

Is the loss of 2" on the freeze switch line a big deal? D I need to order another one?

I hear gas seeping from low side AC port. Is that normal?

Compressor clutch not engaging.

Alan

You need a new freeze switch (BTW it may have been working fine - if it freezes up the evaporator the compressor must stop - since it won't do any good keeping it running... will just stop all airflow and overload the blower motor too).

This happens when your AC works well and the air is very humid, if the freeze switch works properly you should hardly notice the cycling.. since the evaporator will still be cold and not totally frozen over...

You also have a leak - so you will need to fix that and recharge.

Alan

Mrmerlin

the metal line that broke is a hollow tube filled with liquid once the liquid gets cold enough it will shrink thus opening the switch connection to shut off power transfer to the compressor

since you broke the tube the fluid has leaked out and the freeze switch needs to be replaced

MainePorsche

When you go in with the new freeze switch capillary tube, you can visualize exactly where it's going. Do this by peeling back the rubber sleeve between the evaporator housing and the blower neck. There is a small channel that the tube should enter to seat in the midst of the evaporator. You may need to snake your arm and do 'fingertip guidance' to seat it right. This would require a second person advancing the tube gingerly at your direction.

dprantl

It is possible to damage the evaporator when trying to insert the freeze-switch tube and/or its guide into the HVAC box since its proper installed location is between the evaporator fins/tubes, therefore one should be very careful when installing a new one. If while inserting the tube you feel resistance, that is most probably the tube hitting an evaporator tube, so never ever try to force it but instead try to pull it out and insert at a slightly different angle.

Dan
'91 928GT S/C 475hp/460lb.ft

Alan

Indeed - you don't want to have to replace the evaporator - that IS a big/nasty job....

Alan

awilli6

Thanks for all of the advice. I was able to pull the rubber back and see where the freeze switch wire should go, unfortunately, because of all the attempts to get it in correctly before I read your responses, I can't see the Chanel or hole the wire should be fed through. I hope I didn't bend the fins down around the hole.

If I can't get the wire back in, can I run/ will the AC work without it fully seated? I can always turn the AC off for a few minutes every so often to ensure it doesn't freeze.

Sorted the vacuum leak behind the pod today so reversing the always cold rigging. Compressor won't come on so I can't check if it will cool enough for Memphis heat. Vacuum is holding in the system so if the compressor comes on, it should work fine.

Mrmerlin

ahh there isnt any special hole per say,
the thin tube is just inserted into the evaporator fins .

it will make its own hole as its inserted ,
just be careful to not force it ,
as it has to slide around the tubes,
a gentle touch is necessary

MainePorsche

You can run the AC by bridging the two wires that attach to the freeze switch. You will then obviously lose its function. The more humid, especially like driving in a torrential downpour, will cause 'snow' to come through the vent with the AC on - so avoid driving in this condition. Another thing you can do is to turn the AC off and turn the fan up high the last mile you drive before parking to run air through the evaporator while it is not cold. This will dry it out a bit and keep mold and/or residue from accumulating. Operating without a freeze switch is not encouraged, but you can take some measures.

You can use an angled mirror like the one depicted to look down the chamber to see if your guess was right, and you deformed some fins. You can then isolate the tube track and try to use the right angle pick to 'clear a path' softly to allow you to re-insert the capillary tube.
Add: Those pics are Craftsman and come in handy for many things.

awilli6

Thanks for the ideas with the tools. My hand is to large to enter that space. Good to know about the wire making its own hole. I've got a clearer understanding now.