98 Malibu AC/vent problems

[jpar1983]

2 issues with my AC - first probably not fixable by me is that it blows no cold air. This is not a simple buy-the-can-recharge-it-yourself issue. Tried it. Took it to a mechanic (I think a reliable one) who said the compressor clutch has shorted out, needs new compressor, possibly new control head. I have noticed that others with Malibus seem to have this problem and were able to fix it, i.e. not a shorted out compressor clutch. Anyone have any advice on this issue?

Also, problem number 2 - the air blows from all vents every time. I turn the dial to tell the air where to come out and nothing happens. Air always blows from all vents, front, defrost, low, side. As a result I have to crank up the fan speed (noisy) to get any amount of airflow out of it.

I am now thinking of keeping this car longer than previously expected so would like to see about fixing these things. would love advice if anyone can offer it! Thanks!

[Tech II]

Took it to a mechanic (I think a reliable one) who said the compressor clutch has shorted out, needs new compressor, possibly new control head.

That is something said by a person covering his butt.....

One if a clutch is shorting out, it would blow a fuse......

Two, you turn the A/C on, to see if the clutch engages.....if it doesn't you disconnect the harness to the clutch and attach a test light to the harness.....if you turn A/C on, and the test light doesn't light, it's not the clutch.......this car uses a pressure switch......to check, you attach hi/lo gages and read system pressure...you attach a scan tool to get a reading from the switch.....pressure should be equal to the gages(which should read the same if the compressor is not running)....Pressure on the gages and the scanner should just about equal ambient air......so on a car that is cold, first thing in the morning, if it's 50 F outside, pressure in system should be close to 50 psi......if much lower, then you have a leak.....

I assume it's cold in Indiana, and if the temp outside is less than 40F, then that compressor will not run anyways(it's built into the PCM not to turn the compressor on if the temp is lower than 40F)........

Now if the car is in a garage and running, and at normal operating temp, the ambient air will be higher than 40 F and the clutch should engage.......however, if the system pressure is too low or the pressure switch is bad(telling PCM pressure is lower than it actually is), then it won't....

As for direction of air flow is concerned, you have one of three things.....the mode valve can be cable, vacuum, or electrically controlled.....either cable is broken, vacuum is missing(break in a line/disconnected), or bad actuator or harness or control head....

[brcidd]

Mailubus are famous for the control head issue-if you have a manual system- which it sounds like you do--- with the blinking green a/c light- is yours this way? there is a fix for degreasing the bad contacts behind the blower speed switch.

[FISH96]

http://www.imcool.com/articles/airco...Repairable.pdf

just sent you pm go to this link and the instructions for repair are there.

i have done this twice on my 2002 malibu with complete success.

[rkvons]

Originally Posted by FISH96

http://www.imcool.com/articles/airco...Repairable.pdf

just sent you pm go to this link and the instructions for repair are there.

i have done this twice on my 2002 malibu with complete success.

Wow! Good to know.

[jpar1983]

Originally Posted by FISH96

http://www.imcool.com/articles/airco...Repairable.pdf

just sent you pm go to this link and the instructions for repair are there.

i have done this twice on my 2002 malibu with complete success.

Wow, just pulled up that page and thought "Who's been taking pictures of my dashboard?" Looks almost just like my '98. Anyway that sounds easy enough, I honestly even think their time estimates are a bit liberal so I might have to try that asap. One question though - after cleaning the PCB, why the thin coat of graphite? I would have thought that could disrupt the circuit and keep it from connecting correctly.
Any thoughts on that blower? I would love to fix that one myself but I kind of doubt if it is something I could do.

[FISH96]

graphite is powdered a carbon derivitive making it an excellent conductior of electricity.

it is good that you asked your question. on both repairs i left this step out.
just did not have any around, suppose soft pencil lead (graphite) could be used as well.

I cleaned the pcb and contact fingers with crc qd electronic cleaner very mild
solvent using a lint free paper towel. i also lightly bent the contact fingers down for better contact with the pcb.

getting the head out is not very involved. slpitting the control head to get at the pcb and fingers is a bit ticklish. you must patient and easy so as not to break any holdin tabs. small thin blade screwdrivers work well.

perhaps you can show this to someone who could assist you in the repair.
just make certain this is your problem and not something else.