Please help testing A/C Clutch Cycling Switch
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Mountain Pass
Joined: Sep 2003
Posts: 139
Likes: 1
Please help testing A/C Clutch Cycling Switch
Hi and thanks in advance,
How would I test (if Possible) the A/C Clutch Cycling Pressure Switch on my 88 E-150 4.9L? I had to replace the evaporator, it was leaking along a seam. I have a feeling the Cycling Switch is bad too.
I was hoping for a simple test w/o Gauges. The Switch is in a real tough spot to remove it. I also heard they could be adjusted. Any info would be greatly appreciated. There are no leaks in the system and no blockages, that we detected when we evacuated and recharged the system.
Thanks again,
Frank D
How would I test (if Possible) the A/C Clutch Cycling Pressure Switch on my 88 E-150 4.9L? I had to replace the evaporator, it was leaking along a seam. I have a feeling the Cycling Switch is bad too.
I was hoping for a simple test w/o Gauges. The Switch is in a real tough spot to remove it. I also heard they could be adjusted. Any info would be greatly appreciated. There are no leaks in the system and no blockages, that we detected when we evacuated and recharged the system.
Thanks again,
Frank D
Thread Starter
|
Mountain Pass
Joined: Sep 2003
Posts: 139
Likes: 1
I found out how to test the A/C Clutch Cycling Pressure Switch , long story short its not working.
At an idle with a fully charged system no leaks etc. I have approx 60lb back pressure, 125lb on the high side.
With engine running at cruising speed 44lb back pressure 225 high side.
At idle the A/C is warm at the cruise speed its blowing cold air.
The compressor is working properly at cruising speeds.
My question is: Could the in operative A/C Clutch Cycling Pressure Switch be causing the problem?
Thanks
Frank D
At an idle with a fully charged system no leaks etc. I have approx 60lb back pressure, 125lb on the high side.
With engine running at cruising speed 44lb back pressure 225 high side.
At idle the A/C is warm at the cruise speed its blowing cold air.
The compressor is working properly at cruising speeds.
My question is: Could the in operative A/C Clutch Cycling Pressure Switch be causing the problem?
Thanks
Frank D
Mountain Pass
Joined: Sep 2002
Posts: 148
Likes: 6
If the switch isn't working as you say and the compressor is running, then what you mean by the switch not working is that it won't cut out the compressor. How did you test that? You would have known when you charged the system back. Until you get enough freon in the system, the ac clutch will kick on and off because the pressure is low and then builds as the compressor is off.
If your compressor is always running, that is not why the air is warmer at idle. It is normal for the air to be warmer at idle because the suction/low pressure is quite a bit higher at idle then at cruising speed. The faster the compressor runs, the more suction it puts on the low side of the system and the lower the pressure goes. The lower the pressure, the colder the air.
If your charge is correct, the only thing you might check is that the condensor is clean and not clogged with bugs, radiator too. Also check the fan clutch. If it is not working right, it won't run faster when the temp gets high and the pressure will get high during idle.
If your compressor is always running, that is not why the air is warmer at idle. It is normal for the air to be warmer at idle because the suction/low pressure is quite a bit higher at idle then at cruising speed. The faster the compressor runs, the more suction it puts on the low side of the system and the lower the pressure goes. The lower the pressure, the colder the air.
If your charge is correct, the only thing you might check is that the condensor is clean and not clogged with bugs, radiator too. Also check the fan clutch. If it is not working right, it won't run faster when the temp gets high and the pressure will get high during idle.
Thread Starter
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Mountain Pass
Joined: Sep 2003
Posts: 139
Likes: 1
Situation resolved:
When the evaporator was installed, no Orifice Tube was put in. After pulling out the remaining hair on my head I figured it out. Popped in an Orifice tube, and new accumulator and the A/C works like new!
I got an education in A/C for sure, and resolved to now do all auto repairs myself.
Thanks
When the evaporator was installed, no Orifice Tube was put in. After pulling out the remaining hair on my head I figured it out. Popped in an Orifice tube, and new accumulator and the A/C works like new!
I got an education in A/C for sure, and resolved to now do all auto repairs myself.
Thanks
Hotshot
Joined: Jan 2004
Posts: 19,762
Likes: 1,079
From: St Louis
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