A/C compressor not turning.

[terrybpp]

In preperation for a hot Florida summer I am starting to work on my A/C system. Everything works except the compressor pulley won't engage. I checked the fuse and the relay under the hood. Could it possibly be the dash switch? Any help would be appreciated.

 

[BBQ_HotDogs]

I noticed a few months ago that mine wasn't working also. I took it to the Ford Dealership and because it was just a tad low on freon, it would not come on. Could be your problem also. Hope that helps.

HotDogs

 

[FrankX570]

Yikes, I have an a/c compressor problem as well. though i just saved myself a butt load of money. only trouble is I won't have a working a/c.

you know that plug on top near the bearing? well today i just noticed when the bearing would spin, it would eat away at the plug. so i figured damn, i better replace this part. after ordering the part from napa, and reserving a garage date, I realized something...I realized i could just bypass this and go with a non a/c belt hook up...

anywho i'll have photos of the burnt out plug and the bearing......

i don't mind this though...i've never used the a/c...so it wont bother me....

 

[BBQ_HotDogs]

i don't mind this though...i've never used the a/c...so it wont bother me....

LOL, but we are in the South. Threre is not a month that goes by that we don't have days where it is just too hot to go without the A/C. We HAVE to have it working yearly. LOL.

HotDogs

 

[Mike_H]

Mine did that last summer. I tested the high pressure switch and that was the prob. The high pressure switch will not let the compressor turn on if the freon pressure is to high or too low. When the switch goes bad the compressor just will not turn on. If you want directions on how to test it I will look it up for you!

Mike

 

[terrybpp]

Where is the high pressure switch located?

 

[Glacier991]

it's on the accumulator, near the firewall on the pass side.

 

[Bruce Rock]

The A/C cyclic switch is located on top of the suction accumulator/drier assembly and controls cycling of compressor clutch. When the pressure rises to 276-324 kPa (40-47 psi), the A/C cyclic switch closes. When the pressure drops to approximately 152-179 kPa (22-26 psi), the A/C cyclic switch opens to stop the compressor operation. In ambient temperatures below approximately 10°C (50°F), the A/C cyclic switch will not allow compressor operation because of low system pressures not being high enough to close the switch.

 

[terrybpp]

So how do I get the compressor turning so I can charge it?

 

[Bruce Rock]

So how do I get the compressor turning so I can charge it?

BACK TO BASICS!

What is the pressure of R134a at the temperature you are trying charge at?

 

[terrybpp]

BACK TO BASICS!

What is the pressure of R134a at the temperature you are trying charge at?

I have no idea. The can of R134 said put it on max A/C and dispense the can. The problem is that without the compressor turning the R134 won't go inot the system.

 

[Bruce Rock]

This site has a chart for R134a.
http://www.hychill.com/tech/ptc.htm

Note that at 72 degrees F the pressure of R134a is about 73 psi. If the container of R134a you are using has any liquid in it at all the pressure will be 73 psi provided the temperature STAYS at 72 degrees. Under normal chargings situations this WILL NOT HAPPEN! Just as it takes heat to change water from a liquid into a vapor, it takes heat to change R134a from a liquid into a vapor. This energy comes from lowering the temperature of the remaining liquid. Did the can you were using for charging feel at all colder than ambient? If it did R134a was going into the system. It can take quite a while to empty a 12 oz can. How long did you wait?

 

[terrybpp]

Alright, I jumped the compressor off of the A/C relay and it turned. So I put 1 can of R134 in the system. The A/C never got cold. Then when I hooked the the compressor up the right way it still didn't rotate. I know the R134 didn't leak out. Any other suggestions?

 

[Bruce Rock]

Alright, I jumped the compressor off of the A/C relay and it turned. So I put 1 can of R134 in the system. The A/C never got cold. Then when I hooked the the compressor up the right way it still didn't rotate. I know the R134 didn't leak out. Any other suggestions?

How do you know the R134a didn't leak out? What are your system pressures?