scumfrog

I just got my 2007 f150 checked out by a great mechanic and he found that the electric auto clutch was going on and off way too often. The pressue on the high side would go from 240 down to 170-180 and then back up to 225-240 and it did this constantly. Therefore there was never a steady pressure maintained. He said it should stay between 225-250 and that a manual clutch was much better but he knew Ford had changed to this new type clutch and his thought was if the pressure could not be kept constant then the A/C in the cabin would never stay constant. I posted several threads about the poor A/C in the f150s and he really believes the clutch is the problem. My r134 level was the correct amount and there were no leaks just the clutch issue. Has anyone other than me been told this? This mechanic has been reparing A/Cs over 10 years. He says he has never seen a clutch work like this before. Meaning not keeping the pressure constant and going on and off so much. Unfortunately this is a warranty issue and he is an independent business shop owner. I know Ford is just going to say there is nothing wrong so I can't even get it taken care of by warranty because they will not think it is a problem. What a Catch 22 situation.

ktmboyz

How often does it cycle?? Ford systems operate on a cycling switch which turns the compressor on and off and is a normal operation.. excessive cycling is usually from a low charge.. the systems he would be refering to would be a system with an expansion vale to control the compressor clutch and system flow...
Is you're system blowing cold ?? How often does the compressor cycle?

obusnizzle

take it another dealership!

scumfrog

It cycles almost every 2-3 minutes. I have had it to two dealers, and neither one commented about the electronic clutch and the frequent cycling. The pressure just does not keep constant. Ford and the dealer both say it is in specs. Ford believes the dealer of course. It is almost like the Ford mechanics don't know what to check. This independent tech was the first to notice that the clutch was not working correctly. I have lost all faith in Ford and its techs for being problem solvers. That is why I say I can't get it fixed under warranty since the dealers and Ford both say there is no problem. So they just say there is nothing to fix and I should be happy.

scumfrog

It blows at its very best 50 degrees out of vents and that is in the shade in 75 degree weather.

NGM

Whats the low side doing? All you gave were high side pressures. It could be cycling on the low side. If thats the case you either have a restriction or low r134a charge regardless of what they say.

ktmboyz

Sounds like you could have a bad cycling switch... I don't know what the local mechanic told you but ford systems are supposed to cycle!!! There are two types of a/c systems, those with a cycling switch and fixed orrifice tube ( what you have ) and then there are expansion valve systems that have an expansion valve with a sensing bulb in the evaporator core that controls system pressure..

I'm not saying you dont have a problem but you're compressor clutch is supposed to cycle,, sounds like you'res is too much.. as the compressor cycles the pressures rise and fall !!!! high and low side

I know my 06 will blow low 30's but it hasn't gotten too hot here yet, most I've tried it in is prob 70deg ..

NGM

My 05 is in the 30's too. It dosen't cycle. There is enough pressure in the system so it dosen't shut off.

scumfrog

Mine will never get close to the 30's. I think the clutch he was referring to was the clutch for the radiator fan. I think the switch is bad too. The low pressure stays in the 40-45 range. It seems to cycle way too often so that the high end pressure never stays steady very long before it drops down to 170 to 180. I hope the dealer will put in a new switch. Also, the dealer told me the 2007 had a auto adjusting orifice valve or expansion valve and not a fix orifice valve. I also thought it had a fixed valve as you guys said.

NGM

Then if thats the case, put an electric pusher fan on the front of the condensor. Wire it so its on when the ac is turned on.