Hey Dave, A compressor cycling too often is usualy due to a low charge. Can't confirm without low & high pressures.
Basicaly when there is not enough refrigirant, the low side pressure drops too low and the low pressure cut off switch turns off the compressor. Depending on when your system was made there could also be a high pressure cut off switch as well. Good luck George -------------- Original message -------------- > Hi all, > > I thought the AC was a little weak in my 300E yesterday, although it > was 102°F outside. Today I drove it with a digital thermometer in the > duct. The temps fluctuate between 49°F and 54°F, with fan speed on > high OR low. Seems the system is cutting the compressor off way before > it should, at least that's my guess. > > Question: What controls this? Is it *only* the evaporator sensor in > the side of the heater/evaporator box, sending a signal to the > pushbutton unit? Or could there be something else acting up? I found > the FSM section on testing the evap sensor, I'll see if that's within > spec, but if it is then I'm out of ideas. My other 124 will fluctuate > about 10° cooler (say, between 40-45°F), which is what I expected. > > If it were low on charge (which I'm fairly certain it is not), the > compressor would run all the time, trying to cool down to the sensor > limit, correct? The system seems to be sort of working as intended, > just at a higher temperature than it should. (???) > > > Best regards, > > -- > Dave M. > Boise, ID > 1994 E500 - 94kmi (Q-ship) > 1987 300D - 258kmi (Sportline) > 1986 300E - 206kmi > > _______________________________________ > For used parts email [EMAIL PROTECTED] > For new parts see www.buymbparts.com > For repairs see www.oldworldauto.com > > To Unsubscribe or change delivery options go to: > http://striplin.net/mailman/listinfo/mercedes_striplin.net
