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Air Conditioning question

1401 Views 6 Replies 4 Participants Last post by  aaronn71
Hi all,

My beloved 201 has, for the first time since new, started to let me down with the a/c. In city traffic and when idle, no cool air blows through the vents. Once I have some speed up and after a minute or so of this speed, the air begins to cool down. The little bubble on the top of the cylinder thingy under the bonnet has white gas flowing through it when the a/c is on, suggesting gas flow, but the aux. fan does not seem to be starting up when the a/c is turned on, nor does it seem to come on when the engine is hotter than normal. Does the a/c need this fan to blow air trhough the system to cool effectively? Could it be that as a result of the aux fan being inoperative I am getting poor a/c performance? HELP! Sydney is HOTTING UP!
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· Registered
85 190e
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7 Posts
serp belt

so, I think I had a similar problem that, touch wood, is now fixed. my a/c seemed to cut out when idling and my temp appeared to go up a little higher than I thought it safely should. Took it in and they fixed the following: Dual temp switch, wire connection from aux fan to receiver drier, serpentine belt & belt tensioner shock. Not saying your has all of the following issues (sounds like we had the same set of symptoms). I'd start with the belt and go from there. hope this helps.
 

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85 190e
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7 Posts
don't have the bill with me sorry, it was under a hundred. or roughly equivilant to three...

don't have the bill with me sorry, it was under a hundred. or roughly equivilant to three kangaroo pelts ;)
 

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1996 Stang, 1995Jeep
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22 Posts
your aux fan fuse may be bad, or the fan itself, or both. when your evaporator doesn't ...

your aux fan fuse may be bad, or the fan itself, or both. when your evaporator doesn't work too well (as when your a/c fan doesn't blow air)your coolant temp goes up. then your ac will shot down to avoid explosion. So, fix your aux fan and then see what happens...
 

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1985 190E 2.3
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37 Posts
Any idea how to check if the aux fan is working? I think I might have the same problem ...

Any idea how to check if the aux fan is working? I think I might have the same problem too, I just got the fuse replaced, and still no improvement.
 

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W201 190e 2.0 Litre
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5 Posts
Discussion Starter · #7 ·
Aux fan/airconditioning

PROBLEM FIXED!!
All that was needed was a top-up of a/c gas. Apparently the aux fan will only engage when the engine gets up to 100deg centigrade, or if the a/c is engaged, and the pressure in the reciever/drier reaches a certain level. If the a/c unit is low in gas, it does not reach this pressure and therefore does not engage the fan. Be wary, though, my a/c only needed topping up because the last (and first) owner had not done so since 1989 when the car rolled off the sghowroom floor. You could be wasting money if your system has a leak (checked with dye at your service point)as the gas will simply escape again, and you are back to square one. A replacement compressor is mega-bucks!
Thanks everyone for your advice.
 
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