My a/c blows cool, not cold. I replaced my CCU with a good workin unit and still the same symptoms. I originally believed that I had a low freon a/c problem in my '84 300sd. I was watching the compressor and the clutch won't engage when the A/C is turned on. The wires are connected and the fuse is fine. Any suggestions?

Thanks

If your Freon is too low, the compressor cut out switch located on the Receiver/Dryer will keep the compressor from coming on. It also could be a bad fuse, bad compressor clutch, or bad connection to the clutch. Some more troubleshooting needed for futher help.

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D. Blake
86 300SDL 340K (for sale)
83 300SD 205K (gone)
06 Chevy K3500 LBZ CCLB 50K
94 Chevy K2500 6.5L TD 250K (gone)

It sounds as if you have a low refrigerant level which will cause the low pressure switch to open, interrupting the clutch circuit. You need to start by connecting gauges and start from there.

Good luck,

Howdy,

I'm sure you'll get plenty of a/c advise here, but here's mine: take it to somebody that has a guage set and knows how to use it.

If the suction pressure is low (which cuts out the compressor), you could have low freon, a clogged evaporator, or a bad thermo expansion valve. If you are truly low on freon, the head (discharge) pressure will be down because you are breaking the liquid seal in the receiver.

If you have some other problem and you put more freon in, you could over charge it which would lead to much higher head pressures. That will kill a compressor.

Also, if you are low on freon, you are also probably low on compressor oil because it leaks out with the freon. If you just put freon in, you will be even lower on oil and will fry a compressor.

JMHO.

Sholin

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What else, '73 MB 280 SEL (Lt Blue)
Daily driver: '84 190D 2.2 5 spd.