Climate control on 96 9000 2.3 LPT CSE

Folks...the ACC has started behaving oddly. It works for around the first 30 minutes of a journey, though tends to heat the cabin a bit more than the temperature setting suggests it should. After that time the air coming out of the ducts rapidly cools, until even with the control set to 21C it's just plain outside temperature air. If I crank the setting up to (say) 25C it will warm up for a while, then it's back to cold again. So does it just need a gas top-up or is it something expensive? The compressor is obviously kicking in, so what's left?

What does the jury think?

Reply to
Pidgeonpost
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Have the exact same problem with my '95 (otherwise same car). Asked here a year ago or so - replies covered various good ideas (replacing the cabin temp sensor/fan, resetting the ACC etc) - but none hit the problem :( I see it both in cold (0C) and warm (25C) weather - in warm weather it's definitely not just 'unprocessed' outside air, but COLD.

/Per

Reply to
Per Laursen

I'm watching this thread as well. My '97 does this when it is cold out. I have not noticed any oddity when it is hot out, though. Basically, after about 1or so hours driving in the winter (cold, here in the northern hemisphere) the HVAC starts blowing cooler air. My '95 did not do this as far as I remember. The ACC from the 95 is controlling the system. I do not think it is the temp sensor in the dash, but probably the one further up stream. I do not know where this sensor is, but would think it would be on the inlet side of the heater core. If someone here has more info on the rest of the ACC system, Please let us know. My guess is that it is heat soaking it to the point that the ACC thinks the incoming air is warmer than it actually is.

KeithG

Per Laursen wrote:

Reply to
KeithG

OK, I went to the EPC. There is a 'Mixed Air Temp" sensor on the right side of the main HVAC unit behind the dash. I do not know the best way to get to this, either remove the glovebox/RHS airbag (on LHD cars) or maybe through the top after the dash cover is removed.

I guess this could be bad or just a bit off. I do not yet know if there is a way it could be better insulated or what, but you may want to see if you could pick one up in a JY just to see if it behaves differently.

9k '93-'98 part number 43 18 788. This was a running change in mid '92 from 96 29 395 which was from '90-'92. Let us know what you learn.

KeithG

KeithG wrote:

Reply to
KeithG

I wonder if the fresh air vent is stuck in the "no fresh air" position. The vent on my 98 9000CSE is controlled by a motor which failed a couple years ago. My symptoms were different in that my problem was that the interior fogged up after 15-20 minutes of driving. However, it seems to me that if the ACC system is tuned for fresh air of a known temperature, and that air does not enter the cabin, unpredictable results will occur. I solved my problem by forcing the vent to the open position and unplugging the motor - since I live in a rural area I don't really need to close off the outside air.

Mike

KeithG wrote:

differently.

Basically,

probably

thinks the

weather it's

Reply to
Mike

Thanks, Mike!

Actually, my fresh air door motor died the same way. It is also in the open position never to return to a closed position at least until I find a new motor ;-).

KeithG

Mike wrote:

Reply to
KeithG

This used to happen on my 1987 9000T. I used to unplug the motor and put a 12v power-pack onto it and run it back and forth a few times using the 3 pins on the connector. It seemed to work ok for a long time after this. It seems to get stuck at one end of its travel.

Reply to
Richard Sutherland-Smith

Folks...haven't had chance to do much about this for one reason or another, but re-reading the posts last night jogged my memory about the little fan in the dashboard. Mine had been noisy for a while and as you know they get choked with fluff. I blew it out a couple of months ago with an air duster and then gave it a shot of WD40 (maybe not the finest engineering solution, but no time for anything else). This stopped its irritating buzz, but I wondered last night if the fan had maybe stopped working. I cycled the ignition (which kicks the fan into life for a while), then gently poked the plastic extension from an aerosol can down the fan duct. Hmmm. No clatter from the fan. Waggled the extension around a bit, and now the fan is definitely running even if it wasn't before. Today the problem seems to be fixed - i.e. no icy blast after 30 minutes running, but then again, the weather has warmed up a bit here in the UK. Afraid we're going to have to wait and see. I hope it provides a fix, as it's one hell of a lot cheaper than open heart surgery on the ACC system!

Reply to
Pidgeonpost

Thanks for the tip. My sensor fan has just started making noise @ 123k on my '94 CSE. I'll try your suggestion and get back to the group on if it worked or not.

Craig

Reply to
Craig M. Bobchin

Per,

Have you manually RESET the climate control module first?

I had a similar problem on my 1994 9000 and this cured it.

BM

Reply to
BMRider

If you're referring to the 'press the two corner buttons simultaneously' reset, then yes, I tried that - no effect.

/Per

Reply to
Per Laursen

OK....as far as my car is concerned, I've checked the dashboard fan daily for several days now, and more often than not the fan does not run when I start the car in the mornings. I don't know the cause - could be fluff, motor dying - who knows. I've determined this by GENTLY inserting a fine tube from an aerosol can into the fan grill. No rattle from the fan blades = fan not running. By gently moving the tube around I am able to coax the fan into life. Once started, it seems to run for the whole journey, and the problem I originally reported doesn't happen. This is hardly a long-term solution though! I had hoped to change the fan myself, but on this model year you have to remove the passenger airbag (apparently), before you can remove the ACC panel, and then the fan. On models with no passenger airbag I believe it was easier. For what it's worth folks...

Reply to
Pidgeonpost

Interesting - I'll try that. I remember removing the dash fan (sitting just below the two seat-heater controls) once - no big deal, but I'll have to (re-)experiment to document exactly how... I'll try to find time during the weekend.

regards Per

Reply to
Per Laursen

The dash fan is a bit different from the other dash mounted switches and controls as it has a round shape behind the panel, with a diameter that exceeds the size of the rectangular hole in the panel. Thus it cannot be pulled out of the panel. I have removed it once and then I first removed the ACC electronics box (just pull it out, maybe with some screwdriver help on the top and bottom) and then through the new large hole you can access the fan which is just located to the left of the ACC box.

Reply to
th

...sounds well worth a try to remove the ACC panel without removing air bag etc. Must admit I'm a bit nervous about playing with that! I wondered why you couldn't get the fan out through the front - now I know...thanks!

Reply to
Pidgeonpost

Don't be wary of the ACC box, its a piece of cake to remove. I found the best way was to remove the radio in the usual way, i.e. two pronged radio removal tools, or four drill bits pushed into holes.

Then reach through hole left by radio and push ACC out from back, it's about as deep as a radio unit. If you disconnect the long thin multiplug from the rear, you will need to re-calibrate the system, just press AUTO and the button together when all is reconnected.

Al

Reply to
Al

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