A/C compressor/fan question

[kevinkay]

My compressor clutch spins when I turn A/C on, but front fan does not run (fan in front of the condenser). Is my issue the electric fan, thought I read it needs to be on whenever a/c is running?

EDITING:
NOW finding fan IS switching on after some time - then off, sort of sporadic. A/C air that used to be freezing now runs just barely cool

thanks

[upallnight]

Could be low on refrigerant. What's the low side pressure? What's the High side pressure? What is the ambient temp that these reading were taken? In order to find the problem you will need to know these pressure readings. What is the vent temp when the compressor is running? Without these it just a WAG (Wild Ass Guess).

[kevinkay]

I don't have pressure tester - thats basically how I work - WAG

I was assuming (again just WAG) that if the compressor clutch is engaged my Freon level is OK? Thinking the pressure switch is engaging the clutch??

I do appreciate your reply, but back to my initial question - should the front elec. fan go on immediately and STAY on when A/C is engaged?
Thanks,
KEvin

[upallnight]

No the ac fan does not come on immediately but does cycle on and off depending on the command it receive from the DME. Even if the compressor cycle on doesn't mean the system is not low on refrigerant. There maybe enough refrigerant to deactivate the low pressure switch but the system is still low so it is cycling off once the compressor is operating. Again this can be confirm by looking at the low side pressure and seeing if the reading is so low that it is activating the low pressure switch.

[kevinkay]

Just checked Harbor Freight - manifold set is $55.
am I using R134A in a 2004 X5?

THANKS

[upallnight]

All BMWs went to R134a back in 1993.

[kevinkay]

Bought a manifold and read and re-read the directions and when I was ready to test
Boston weather turned cold, 50 degrees outside, I got readings of 26 on the low side and 60 on the high side.
(Using the dash temp as the 50 degree "ambient" ).

Read some documentation that if both sides are low it could be "clogged inlet screen" so I immediately imagined my cabin filter was all clogged up with pollen, leaves or a plastic bag got pulled in and is restricting air flow - raced out to check it.........but it seemed fine.

So if low refrigerant is the problem , and the issue started within a month or so does that mean i have a leak and a fast leak?

for some reason it is still my "wild ass guess" that the issue is the front fan, it did not go on all today during the test unless being 50 degrees didn't warrant the fan coming on??

So what do I do next, try to charge it and see what happens?

[upallnight]

Pressure are low even for an ambient temperature of 50F. If your system is low, you have a leak. When you removed the caps to attach the gauges, was there pressure underneath the caps? The valves could be leaking.

Also when you use the bayonet fittings did you twist down the knurl knob to open up the valves?

[kevinkay]

I might have noticed some pressure when I removed the caps.

Bayonet fittings are where I attached the hoses of the manifold to the car, like the fittings used on an air compressor? I pushed it onto the car male fittings then opened that valve (turing clockwise) and the needles rose on the gages. I tightened those valves(turing counter clockwise) before I removed the hoses from the car and the gages stayed (and are still) at 26 and 60.

IF the valves were leaking, is it like tightening the valve in a tire?

IF it were leaking, does it leak constantly or only when the A/C is on? If I keep testing and see pressure keep dropping it confirms a leak?

My next step is to charge it and see if it holds??

[upallnight]

If the valves are leaking an AC shop can replace the valves without emptying the system of refrigerant. They have a special tool that they use to remove and replace the valves while the refrigerant is still in the system.

Yes it will constantly leak until the system pressure and atmospheric pressure are equal.