Another air conditioning problem thread...help please

[rc1626]

I have a 99 Ford Explorer and since the end of last season my ac has been going down hill. The air coming from the vents has gotten warmer and warmer. I went out and bought a set of guages and here is what I've found.

With engine running and ac set to MAX:
Low Side:
22-45 sometimes going to 55 as compressor cycles.

High Side:
125-140 as compressor cycles.

The compressor is cycling almost constantly.

Any ideas?

I don;t know if I have an expansion valve or orifice tube? Could that be blocked. Could it be the swith on top of the evaporator(think that's what it is)?

Obviously I'm a newbie but looking to learn.

Any help would be greatly appreciated.
Thanks!
Rob

 

[rc1626]

I posted this over in the ac forum as well but thought it may get more views here. Sorry for the double post.
I have a 99 explorer and since the end of last year the ac has blown warmer and warmer air.
I bought a set of guages and hooked them up and hear are the numbers I got:
Low Side:
22-45 sometimes going to 55 as compressor cycles.

High Side:
125-140 as compressor cyles.

Compressor seems to be cycling constantly.

Any ideas?

Blocked orifice tube or expansion valve? (don't know which one this car has)

Could it be the switch on top of the evaporator? (I think that's what it is)

Any help would be greatly appreciated.

Thanks in advance.
Rob

 

[joshuaj0214]

The high side should be around 240 and 30-35 on the low. The switch on the evaporator is a low pressure switch, it will not let the comp. kick on when the press. gets to low. I dont know about the orfice tube though. I also am not sure why the comp. is constantly cycling? Anybody else wanna add to this?

 

[rc1626]

Just to add ambient temp was about 90 when I checked the readings.

 

[rc1626]

Thanks Josh. Just wanted to add that the ambient temp when the readings were taken was in the low 90's.

 

[joshuaj0214]

I just charged mine yesterday and it was also 99 degrees in the shop!

 

[rc1626]

Well after reading around it sounded like my car was a classic case of low charge. I'm assumuing the compressor was cycling so much because the cycling switch kept seeing the low side pressure go below 25psi. This was happening constantly. Once I started adding r134 the time between cycles got greater and greater and my guages started to read appropriately. A/C is now blowing cold.
Let's see how long it lasts though. Could be I have a leak somewhere. Well, I'm going to enjoy it while I have it. Thanks again.
Rob

 

[rc1626]

Figured out the problem. Classic case of low charge as I have learned. She's working beautifully now.
Thanks again to this board.
Rob

 

[trucku]

Excellent..

 

[Turdle]

I merged the 2 threads.

 

[rc1626]

Thanks jtsmith!
Sorry for the double post. Just happy to have my A/C working again. It's flaming hot up here in the NE right now.

One other quick question if I may. how much of a temperature diff. should there be from the vents in the car to outside ambient temps?

Mine is running now with about a 35 degree difference.

Thanks.
Rob

 

[joshuaj0214]

The air coming out of the vents on mine is 60 degrees, outside them was 95.