Now, the a/c problem:

I bought a gauge set and hooked it up to my a/c system. I serviced the system as per the manual and it took about half a can of R-134, but now I'm seeing something I don't quite understand. When I turn the key on and short the pigtails on the red pressure switch, I'm hearing the aux fan relay click, but when I start the car with the a/c calling for cold air, the low speed fans do not come on right away--even though the low side pressure is at 30 psi.

I watched this cycle that repeated itself continuously at idle: low side 30-40/high side 150 and climbing. When the high side reached 250 psi, the low speed fans came on. The high side pressure slowly went back down to 150 psi and the low speed fans would turn off. All the while, the low side was bouncing around between 30-40 psi. It seems that the high side would climb back up to 250 psi, the low speed fans would come on at that point, the high side pressure would slowly (about 2 minutes) drop back down to 150 psi and then the fans would go off. The a/c was blowing 40 degree air at idle from the vents.

Any ideas?

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1993 400E, 256,000 miles (totaled)
1994 E420, 200,000+ miles
1995 E420, 201,000 miles