Well, here I am again!! First off, I have a '94 S500 with another, hopefully, minor problem. The problem is this, when I'm driving on the highway my A/C will freeze me out. However, in stop and go traffic the cold air stops and once I hit hwy. speeds again it functions as it should. In traffic, I pulled over and popped the hood and the A/C clutch was engaged, however the 2 aux fans in front were not moving. Still, even in heavy traffic, She didn't overheat. The 2 fans do work, because I first start her up, I can hear them and when I pop the hood they are running, but for a very short time, say about 15 seconds, or so and very intermitenly (lousy spelling, sorry!!) I can't speak for the rest of the country, but it is extremely hot here in Mississippi this time of the year and it is NO time to be without A/C!! So, do I have a major problem or, hopefully, a minor one?[sm=sigh.gif] I could take to the dealer, but as my trust in them has decreased considerably, I've learned to trust this forum more!! Besides, you guys and gals are ALOT cheaper!!! All joking aside, any suggestions y'all have will be appreicated. THANKS!!!

 

Is your blower fan working, at highway speeds the air pushes thru!

 

Yeah Peter, everything appears to be functioning properly, including the blower motor. It's just the fact that in stop & go traffic the cold air ceases. Actually, it the cold air doesn't cease entirely, but it's at least a 75% reduction, or more. The whole time the blower is working quite well!! Thank-you for your reply, it is much appreicated!!

 

maybe a low charge? when your moving the ac compressor is pumping faster now at idle its pumping slower. maybe a charge issue. i was going to say maybe your fans arent working but you said they are. could be a bad temp or pressure sensor on the reciever/drier. all of these could be a cause.

 

Thanks for the reply chassis221! When I mentioned the aux fans, they only work for a very short time when I first start her up in the morning. After that, I have not seen or heard them kick in. That's what I meant by them working and I really should have been more clear on that, sorry. Is there a way I can 'jump' those fans to run constantly just until I can see if that may be the problem? I figured I'd try to jump them and then just drive her around in the city for awhile to see if that does make a difference. Tomorrow would be a good day for that little experiment too because it's supposed to get up to around 98 degrees!! If it can be done, how can I do it? Do you know?
BTW, this is alittle off topic, but I noticed that you're from Philly, right? I was born and raised in Lancaster, but moved down here when I was about 35. (I'm 57 now!!)


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Like Chassis suggests...check the refrigerant charge.

Note. How do you determine that the compressor clutch is engaged from looking under the hood. You can HEAR the clutch engage but not see it. Maybe this is what you did.
I didn't want you to conclude that the compressor was engaging when maybe it isn't...but it wouldn't work on the highway either so this is unlikely your problem.

Stuart.

 

Thanks for the reply snanceki! Here's how I came to the conclusion about the clutch. I have the engine running with the A/C off and looking at the compressor I can see the belt turning the pulley with, what I figured is the clutch, not spinning. My wife then turns on the A/C in the cabin and the non-spinning part is now spinning with the pulley it's attached to. When she turns the A/C off that outer part of the pulley is no longer spinning. That's how I knew it was engaging. As for the charge, I'm going to take her to the shop tomorrow and have it checked and recharged if she needs it. Thanks for the advice because, to be perfectly honest with you, that never even crossed my mind to have it checked. Again, thanks for the reply. It was much appreicated!!