So I have been searching the forum for a while now and I can not find anyone that seems to have the problem I have. Maybe it's my searching ability.

Anyway, when I move the switch in the cab to the A/C or MAX A/C position the clutch on the compressor is not engaging. I also don't hear the tell tale click sound. Does this mean it's the relay which is F5 in the cab fuse box?

I'm not sure how to test to see if the relay is good and then also to check the switch.

Thanks!

 

Start here: https://www.ford-trucks.com/forums/7...xpedition.html

 

Thanks! Now I know why I was not finding anything. Searching just the one forum.

 

compressor has a cutout switch for low gas pressure (R134) set about 25 psi. On a 11 year old truck your gas has probably leaked low. You reaaly need a gauge to test, but for a quicky, just dump another can of R134 in and see if the clutch kicks in.. you may need more than 1 bottle to get up to proper amount if the clutch dont kick in at all now.

 

Yeah, I have thought about trying that and seeing if that is the problem or not. I currently do not have a set of gauges but I'm also thinking I will wait a little and then just take it to a dealer and see what they say is the problem. My guess is the coolant has leaked out or is low. Clutch turns just fine by hand and the clearances look fine.

Will let you know what I find out once I get it in. Hopefully not to expensive.

 

Oh, I know one other question. Is the defroster function connected to the AC compressor also? I believe it is, which means I can't defrost my windows in the winter till I get that fixed. Correct?

 

Just a thought but had a similar problems with my dads F150 we grabbed a kit from Auto zone with the leak stop in it recharged 4 weeks ago, and it took 1.5 cans to fill the first time 1 week later we recharged with th remainder of the 2nd can and he has no problems since we have checked it a few times since just to see if it is still leaking and it been fine. Blowing cold @ 52 degrees on even the hottest SC days we have had lately.

 

Did you have any gauges to check what the pressure was, or you just went ahead and added? AC is something I have never played with before and from the research I have done, most owners suggest having pressure gauges before doing anything. Others say, just add coolant and you will be fine.

 

His compressor actually had a pin hole in it and we just went to Autozone (if you have one local if not other suppliers should have the same kit) Quest/32 oz. of refrigerant and 4 oz. of Sub-Zero booster A/C recharge kit plus Stop Leak. It comes with a simple to read gauge, as long as your system has not been taken apart in any way you should not have to worry about pulling a vacuum on the system. We just followed the instructions on the back and it has turned out to be the best $49.99 spent. He had gotten prices on having the A/C system reworked and the compressor replaced and the last price he got was $700.00 and it has been 4 weeks and he drives everyday. We have had days with the as hot as 105 and his truck is blowing at a cool 52 degrees. we just had to check the system and recharge it the following weekend cause the compressor started cycling it held almost the rest of the partial can we had left and this sat will actually be three weeks since the last recharge and he hasnt complained anymore. Autozone actuallys gaurennteed it would fix his leak or his money back.

 

ford guy, it is always a good idea to use gauges.. that being said, you will find that the suction pressure is about 35-40 psi and the high side is about 190-210 psi when running and cold.. so if you but a bottle and have a suction gauge and it says 20 psi--- you got a good idea that you are low on R134.. You can "just add a bottle" and that works 75% of the time, but its a good idea to know what the pressures are... atleast on the suction side.. an dyou can buy a bottle with a gauge kit on it.--- save the gauge and handle and just buy a bottle next time.

 

Thanks for the info. Will let you know once I go buy the kit.

 

So I went and bought a kit finally today. I hooked it up to the low pressure side and the gauge reads 0. So I started the truck up, hooked the canister to the gauge and started to add coolant. Not even 10 seconds of pulling the trigger and the pressure gauge goes into the "ideal" pressure range. I pumped it again and pushed it to 40psi, still with-in the "ideal" range but the compressor still does not engage. Am I missing something else? Every where I read it says if zero on gauge add a can of coolant. But if I do that, the gauge will be in the danger level.

Thoughts? Fuses and relays look ok.

 

You are reading the pressure of the can, not the system.

 

Actually, it's reading the pressure of the system. Gauge reads zero while attached to the can and not attached to the low pressure nipple. Once I attach the hose end to the nipple on the low pressure connector the gauge goes to 40. But, the compressor is not running. From what I just read, the pressure should be 80-100 on the low connection when compressor is not running.

Is this correct? Should I pump it up to 80-100 and then try running the clutch.

Thanks

 

the cans are made to fill up the system if it has dropped to 10-30 psi. IF you have zero, i question if you have a failed hose or something and ALL the gas leaked out. If that is the case and you get air into the system, it will never cool, but the compressor should start. You are correct, with the motor off, the gauge will read 70- 100 psi. After the motor is running and the compressor starts, you will such the low side down to 40 psi, and the high side will increase to 200 psi (some varaition with ambient temp, but this is approx). THe compressor will not kick in untill it sees about 25 psi. Less than that and the pressure switch kicks out. ... When you put 40 psi in the system, will it hold 40 psi till the next day ? If so, put the entire can in, maybe 2.