1999 HVAC issue

[jeffcoslacker]

IO'm sure it's been covered a million times but I've got the dumb today and can't seem to find it.


Looked at a '99 want to buy. Blowing hot air regardless how set. I don't think it had dual zone but I didn't pay much attention to the dash control, nor did I see if the passenger's side had cold air. Duh, sorry. Do they all come with dual zone? If so, that probably answers my question.



Like I said I kinda disregarded the dash and just wanted to see that the A/C was capable of functioning and I heard the compressor snap on when I set it to cool so that aspect of the control was fine, observed the compressor with clutch locked up nice, no cycling and cold, sweaty lines so apparently I probably have a door actuator problem?


Usually just actuator stuck/broken? Any programming issues or etc these are prone to?

[jeffcoslacker]

OK I see the dual control now. It's way over on the right side, near the pass door. Never thought to look there.


So apparently I have a different issue than I thought. Since it blows equally hot out of both sides regardless of setting, I doubt its an actuator issue.



Back to is there a logic control, where is it located, and is there any kind of reset/relearn I can do before giving up?


There is a little other dashboard bumblefuckery happening...fuel gauge jumps around sometimes, dash lighting flickers when in park with headlights on...related?

[brcidd]

First off, a '99 PA is not designed to cycle-- it has a variable stroke compressor that can "run" with as little as 5% of needed refrigerant in it.. So chances are about 100% that it has lost nearly all its refrigerant and is running anyway, and not cooling of course. Seen a whole lot of those V-5 compressors have belly leaks- where the cylinder meets the front and rear head- corrosion crawls in and under the o-rings and causes the o-ring joint to leak out the majority of the systems refrigerant.

You can prove this by just adding refrigerant- but it will soon leak out again. You can tell by looking at bottom of compressor and see if it is oily/greasy as well.

[Blue Bowtie]

brcidd is on it. That's a notorious area for leakage. I've had several as well. The first photos show the UV dye under a lamp, and green is apparent seeping from the ends past the O-rings.



The second photo is so bad it wasn't even necessary to use a UV lamp to find the dye leaking.

[brcidd]

It all started when we "they" quit painting the pumps in 1994, due to EPA restrictions, no one could afford to paint (and stay clean) in the factory, So now corrosion runs rampant on the aluminum surfaces....

[jeffcoslacker]

You guys miss where I said cold, sweaty low pressure lines? It's got plenty of refrigerant. The problem is it's shooting out blazing hot HEATED air from the vents...as in when it was 63F out this morning there was 120 degree air coming out the vents.


I found/did the reset procedure. The actuator on the passenger's side started moving, and now I still have blazing heat on the driver's side but nice ice cold air on the passenger's side. Of course. LOL...


So I will see if the temp actuator on the driver's side gets signaled to go to the cold side or not. If so and it's not moving, it's getting replaced. If not, I'll have to investigate wiring or even a controller issue.

[jeffcoslacker]

Alrighty then.


Moving on...I had a brainstorm and remembered I used to buy a cut-off valve for heater cores when there was an issue. Murray/4 Seasons 84706 if anyone's interested.


That got the heat stopped...and together with my now working passenger's side after the reset, I have icy cold air from that side and acceptably cool air from the driver's side. No more incineration, so I can at least drive it while sorting this out the rest of the way. When I set it to recirculate it picks up the cold air from the right side floor and moves it out the left, it got plenty cold in there, just took a little more time than normal to do it.



I have 40 degree air out the right side vents and my line pressures are dead on the money. So no refrigerant needed guys.


Since one actuator moved after the reset, and they were both initially stuck at the same level of heat, I'm going to think perhaps that's from the car sitting for a prolonged period. I'll pull them both and see if they can be coaxed into movement or maybe a door is sticking, and if there's appropriate power being sent to them. And work from there.

[jeffcoslacker]

Quick update...actuators and/or blend doors came to life after driving the car for 10 days or so. Sounded arthritic and creaky at first, but work fine now and quickly configure to the control's settings. I have no current need for the manual valve I installed, but it will stay there in case other problems arise.