[sybersitizen]

I just bought this car as a treat for my wife. We were originally looking for a second PT, but this opportunity popped up instead. Got it at a pretty good price, but with the understanding that I'll have to spend some more fixing up a few issues.

First up is the AC/heater. The system does cool and heat the interior... but the issue is that the fan speed settings of 1,2, and 3 produce absolutely no activity at all - just like having the knob set at OFF. But move it over to 4 and everything kicks in. I'm hoping this is a simple fix! Could it be as easy as replacing the rotary switch?

 

[ImperialCrown]

More likely it is an open blower resistor. The rotary blower speed switches are usually pretty durable.

 

[sybersitizen]

Hmm... is that something I can take care of, and where would I look for it?

 

[ImperialCrown]

Behind the glovebox? Empty and swing the box out and release the side latches. Then swing it down out of the way.

 

[sybersitizen]

Great, thanks for the help! Knowing what to look for now, I see that this is a pretty common problem... and I found a couple of videos covering replacement of the resistor.

 

[sybersitizen]

I'm baaack.

The blower motor resistor fix went well, and all the speeds work properly now, but...

On two occasions over the last few days, the A/C has sporadically refused to produce cold air. These were both on short trips of ten minutes or so. On trip one, I punched in the cool setting and got only uncool moving air. Tried switching things (the blower on/off knob, vent pattern knob, temperature knob) back and forth to no avail. Then when I had almost reached my destination, the air suddenly got cool. On trip two, pretty much the same thing except that the air never did get cool. On the return home from trip two, the A/C worked fine, and also worked fine the next day.

So what's the deal here?

 

[ImperialCrown]

It would be best to diagnose this when it isn't blowing cool. With the A/C on, pop the hood and see if the compressor clutch assembly is spinning with the pulley. It may cycle on and off. If not, it could be a refrigerant pressure or electrical problem. Any fault codes?
If it is pumping, then check the lines to and from the firewall. One should be warm and one should be cool.

 

[sybersitizen]

It would be best to diagnose this when it isn't blowing cool.

Yep, I will try... but so far I've been on the road and/or busy with duties when it happens.

Any fault codes?


With this car, my understanding is that I have to flip the ignition from OFF to RUN three times within five seconds to show the codes. Most of the time that doesn't do anything... but once in a while I briefly see the text 'done' - so I guess that means no, no fault codes.

 

[ImperialCrown]

Probably no PCM codes then. The key dance will only show PCM (drivetrain) codes.
There may be codes stored in the BCM (body control module) or HVAC dash control module that would need an advanced scan tool to read, but you may have to pay a shop to check for them unless you know someone in the business. These modules can store fault codes, so the problem may not need to be present at the time.
A battery disconnect or memory fuse removal will erase stored codes and the climate control will go through a re-calibration sequence when power is reconnected and the engine restarted with the air on, mode selector on panel and fan on high. Active codes will return right away.
If you find no hard or obvious failures, that might be something to try. Reset your clock when done.

 

[blackstratus]

I had this problem on both of my Stratus's. My 01 it was the control that went. That is the 3 knob control on the dash. My 02 ( now sold) had this problem also, replaced the control head thinking that was also the problem, it wasn't. Turned out the compressor was seizing up on and off. Sometimes it would start and othertimes it wouldn't. i had to take that one to the dealer to check out. So that car got a new compressor. you could tap on the compressor and it would start. Then when it cycled off , it wouldn't turn on again till you tapped on the compressor body.So maybe you have one of those issues. These cars I read also had a TSB for a HVAC control problem too. Maybe someone on here may know that TSB. They also did that for me when I did the compressor on the 2002

 

[ImperialCrown]

There was TSB # 24-002-04A for the re-cal. You can find some info on Google about it. It covered 1998-2004 LH and 2001-2005 JR.

REPAIR PROCEDURE:
1. With the vehicle at room temperature 10°-27° C. (50° to 80° F.), remove the M-1 circuit
fuse for ten minutes to erase DTCs.
2. Install the M-1 fuse and start the vehicle, this will initiate the HVAC system calibration.
Allow approximately five minutes for the calibration to complete.
3. Operate the vehicle and HVAC system to verify that Symptoms and/or DTCs are gone.
If tapping noise or Blend Stall/Feedback DTCs re-occur, additional diagnosis will be
required

 

[Christopher]

I have a problem similar to the second one mentioned with my Stratus. Cold air will start/stop for no apparent reason. I have found that setting the selector to 'defrost' causes cold air to be produced. Often I can switch back to the regular AC setting and it will work fine. That is becoming less reliable and I seem to have to leave it on the 'defrost' setting for longer periods of time.

I've been told in my case it is probably the head unit, but I haven't taken the time to get it fixed.

 

[saltydog]

I have a problem similar to the second one mentioned with my Stratus. Cold air will start/stop for no apparent reason. I have found that setting the selector to 'defrost' causes cold air to be produced. Often I can switch back to the regular AC setting and it will work fine. That is becoming less reliable and I seem to have to leave it on the 'defrost' setting for longer periods of time.

I've been told in my case it is probably the head unit, but I haven't taken the time to get it fixed.

When I had my 02' it did the same thing. I took the control apart, and noticed the knobs where very loose, I went ahead and cleaned the contacts, put it back together, made sure the knobs where snug and the A/C worked as it should.

 

[Christopher]

When I had my 02' it did the same thing. I took the control apart, and noticed the knobs where very loose, I went ahead and cleaned the contacts, put it back together, made sure the knobs where snug and the A/C worked as it should.

hmmm...How do you get the control out?

 

[sybersitizen]

Thanks for the tips so far. I'm pretty sure that whenever the A/C fails, the compressor doesn't kick in at all (that is, I don't feel and hear the normal slight change in under-the-hood activity). I'm still trying to monitor any intermittent failure, but it hasn't happened often.

 

[saltydog]

hmmm...How do you get the control out?

The wood bezel just snaps in place, just need pull around the edges. Once it is out, there are 4 screws that hold the control to the bezel, once that is off I think(been some time ago) thee are 3 screws that hold the control together, once those are off, then you will need to pull the knobs off, then pry the control apart. You then will see the inside. Mine was very dirty, so cleaned with eletrical clear spray and the use Dieo Electric greese on the contact points.

One more thing, when the A/C is not working, try pressing the Rear Def button, for sume reason that would kick the A/C, not sure why. Since my tabs where broken off the rear window, I did not worry about the window getting too hot.

 

[Christopher]

I've tried that Jaime, for another reason. My rear defrost seems to intermittently fail. Sometimes I can't turn it on, sometimes I can't turn it off. Though it will turn off after time. I was trying to see if when one failed, the other would too. Although the trouble may be related, whether they work or not does not seem to be.

 

[sybersitizen]

Thanks for those comments about the control panel knobs, the defrost setting, and the rear defrost button. As it turns out, my car is showing all the same intermittent symptoms, including sometimes failing to turn the rear defroster on or off (and my window tabs are broken too). Definitely something wacky going on inside that panel.

 

[ImperialCrown]

Tab breakage off the rear window grid on convertibles is common. There is a TSB on the repair. It comes from the stiff rear defogger wires flexing as the top is raised or lowered.
If the HVAC control panel has intermittents, you might try removing it to look for bad connections, broken circuit board solder joints (on the larger pins), tarnished switch contacts or replace it with a used one.
These HVAC heads and the BCM do store fault codes, but need a special reader/scan tool like the DRB III (or equivalent).

 

[sybersitizen]

If the HVAC control panel has intermittents, you might try removing it to look for bad connections, broken circuit board solder joints (on the larger pins), tarnished switch contacts...

Did that yesterday, following the instructions posted earlier. (The faux wood panel needs to be pulled really hard!) Mine had what looked like an overabundance of dielectric grease and some minor tarnishing on the metal. I removed a lot of the grease and spruced up the contacts and the wire connector pins. The fact that several things were not working correctly made me suspect that one or two important contacts were affected, but nothing was broken or worn. I got it all back together, and it's working so far. We'll have to see if my 'fix' sticks.