1988 300TE AC Problem - PeachParts Mercedes-Benz Forum

dhjenkins · #1 10-07-2009, 08:52 PM

Quote:

Originally Posted by les_garten

I have a 300TE. You start the car and the AC Clutch engages, the suction line gets cold and blows cold air. Ambient pressure on the suction side 88#. As soon as the system runs I get 55# Low side and 225# High side at 90F ambient temp. The AC runs a couple minutes. Then the front electric fan kicks on. Runs another minute or so and the AC clutch kicks out and the electric fan starts. Will not cycle on again. Stop engine, restart and the whole thing repeats.

So I read and got the suggestion it was the serpentine belt. It was indeed in piss poor shape. It's a good thing i looked at it before it left the car stranded. Replaced it. No change in the behavior.

Where are the usual Gremlins at that cause this?

Thanx for any help! It's hot down here in S. Florida!

Les

You said "As soon as the system runs I get 55# Low side and 225# High side at 90F ambient temp. The AC runs a couple minutes. Then the front electric fan kicks on."

What do the pressures do after the fan comes on? Does it drop below 30 or so?

les_garten · #2 10-07-2009, 11:11 PM

Quote:

Originally Posted by dhjenkins

You said "As soon as the system runs I get 55# Low side and 225# High side at 90F ambient temp. The AC runs a couple minutes. Then the front electric fan kicks on."

What do the pressures do after the fan comes on? Does it drop below 30 or so?

Yes, when the Fan Kicked on the Pressure went from about 250 down to 225 pretty quick.

dhjenkins · #3 10-07-2009, 11:24 PM

Quote:

Originally Posted by les_garten

Yes, when the Fan Kicked on the Pressure went from about 250 down to 225 pretty quick.

I'm more interested in the low-side pressures once the fan kicks in. More than likely, there's a low-pressure switch that can be tripped if the pressure drops low enough (which will happen if you're low on charge and the fan comes on).