AC System

I have an 86 300E. I high pressure washed the engine. I must have gotten water somewhere it was not supposed to be. It was running real rough, and would not drive for a while. I took off the cover for the dist. and ran the engine for a while, and fully opened the hood to the sun. It had died many times and ran rough for about 20 minutes. Then the rough running stopped and runs fine. Now the AC does not work! Is there a relation with one of the relays? Can you reset the relay if it is closed? Or do I need to buy a new one? I first thought it needed more 134 freon...we converted the system, but the system would not engage the compressor, so we did not get any freon in! It seems when you place the temp control on max. and punch in the AC button, the compressor does not engage. I did check the low pressure valve, it has a charged system with freon. What needs to be done?

[J.HIDALGO]

If it is slipping or has some grease/oil on it, it will cause the compressor NOT to engage.

The belt is not slipping, and does not have grease on it. Thanks...Is it normal to have the auxiliary fan go on and stay on before starting every time you turn the key to the on position?

Geof

It is most likely low on refrigerant. There is a low pressure switch that interrupts the compressor clutch circuit in this event to prevent compressor damage.

You need someone to connect gauges and check charge.

Good luck,

Larry,

How do I get the low pressure switch to reset? I tried to put in 134 in the system. It would not take any refrigerant, as the compressor did not come on? I pressed on the low pressure valve, it has pressure. Geof

[jbaj007]

For now, forget the freon issue. The low pressure cut off switch will work even when undercharged moderately. Since the problem started with an engine wash, I'll bet your Klima relay is wet (and hopefully not fried). Check Klima on fender well, drivers side, sorta right behind headlight. Check this and see picture here:http://www.peachparts.com/Wikka/AcDiags

With an 86' 300E do I have a Kilma or MAS? Second, is the auxiliary fan supposed to run every time I start the car, even in cool weather?

[jbaj007]

According to the pictures in Stevebfl"s article MAS started in 1990?

First, thanks for all the messages posted so far. The belt is tight, the Kilma is OK, I think it is just low on freon....On the 86' 300E, how do I locate the low pressure switch? Am I correct in that I take the two wires off and connect them to by-pass the switch and engage the compressor to accept the freon? What order do I do this operation? Start the car, by-pass the switch, fill with 134?

Geof

Has this car been properly converted to 134?

Just because you can get pressure from the a/c system does not mean that there is enough charge to actuate the pressure switch. You need to put gauges on the system.

The switch should be on the filter drier which is in the vacinity of the drivers side headlight.

Good luck,

[Mike Murrell]

Was the A/C working before you washed the engine bay area? If so, I doubt your refrigerant is the issue. Depending on which car wash pressure setting you used, it's possible you knocked an electrical wire loose - possibly one in or on the compressor or clutch.

I always use the pre-soak setting, followed by the fine spray rinse - never use the normal wash setting as the water pressure is to intense.

My 2 cents.

Yes Larry, it was properly converted to 134, about 18 months ago. they told me I showed signs of a small leak around the compressor. I was told it may take 5 months or two years to leak out the freon.

Other post: As I recall, the AC was not responding well a few days before the wash!!!!

Thanks Geof

If the problem is a two year or 18 month leak. Simply connect gauges, check and recharge if low. R134 is cheap and as long as it is not bone dry, there should be no contamination to worry about.

Good luck,