A/C blowing warm then cold idling & overcharged!!!

[CREWZIN]

Originally Posted by 66CUDA

Okay, so the "high pitched" fan I hear running sometimes is the high speed fan, correct? And where is the low pressure switch located and why do the local parts store only show a high press. switch available and no low press. switch? I also wonder if my PCM needs to be reflashed...the dealer flasher as per a TSB when I had a CEL lit a few weeks ago. Also I'm going to replace the cooling fan relay too...its cheap enough.

66CUDA

The "low" pressure switch is also knows as the Cycling Switch and is located on top of the accumulator.

[66CUDA]

The manual says the a/c system should be discharged before replacing either low or high switches. Is this really neccessary?

66CUDA

[CREWZIN]

NO, for the Cycling switch on the accumulator. That just unscrews without a loss but watch out for the small O ring underneath. It squashes and breaks easily.

I found this on the high pressure switch. Apparently you don't loose much coolant either but there is cautions.

WikiAnswers - When installing new ac high pressure switch o ring blows from pressure release. how do i fix this problems

[03hothemi]

Originally Posted by 66CUDA

What's not making sense is that the fan turns on when the pressure gets high and turns off when it lowers it to the correct pressure. To me it seems it could be the switch malfunctioning and not turning the fan on earlier because the switch is telling it to turn off. From my experience when a fan goes bad it either just stops or spins erractically and stops and does not perform the function of cooling down. My fan is cooling down the pressure but it isn't being told to react quicker. Since the switch is easiest I'll do that first and keep ya guys posted....

66CUDA

That could be a new one on me. I've seen where when the cooling fan kicks on per the engine temp switch that the pressure will drop on the low side, but never have I seen the cycling switch go bad and cause the fan to go on and off. The fan is supposed to run constantly if the a/c selector switch is set to a/c. If the fan were controlled by the cycling switch, it would go on and off, but as I said above, it is designed to be on all the time the the a/c is on as well as a short time after is is turned off. Hell, if it's cheap enough, throw a switch in it and see if it works. I love getting an education.

As far as the fan completely quitting comment...my wife's 05 needed a new cooling fan here not too long ago. The fan would work on low speed when tripped by the engine temp sensor, but would not work on high speed when tripped by the a/c system. New fan installed, and no problems with it since. Good luck.

[66CUDA]

Originally Posted by 03hothemi

That could be a new one on me. I've seen where when the cooling fan kicks on per the engine temp switch that the pressure will drop on the low side, but never have I seen the cycling switch go bad and cause the fan to go on and off. The fan is supposed to run constantly if the a/c selector switch is set to a/c. If the fan were controlled by the cycling switch, it would go on and off, but as I said above, it is designed to be on all the time the the a/c is on as well as a short time after is is turned off. Hell, if it's cheap enough, throw a switch in it and see if it works. I love getting an education.

As far as the fan completely quitting comment...my wife's 05 needed a new cooling fan here not too long ago. The fan would work on low speed when tripped by the engine temp sensor, but would not work on high speed when tripped by the a/c system. New fan installed, and no problems with it since. Good luck.

Well I'm hoping its a switch or relay cause its cheap and easy...relacing the fan looks like a few hours of work....By the way...I found two wiring harness connections on the fan shroud. Are these the cooling fan relays? My manual only shows me a radiator fan relay but that has to be working because my engine temp. is normal. If so, which one is the low speed and high speed My 2006 doesn't have them in the engine fuse/relay box by the air filter like the earlier PT's. Which relay would control the fan to come on @ idle?
Any tips on removing them w/o damaging them.

Thx, 66CUDA
66CUDA

[Sharkstooth]

Like Crewzin showed you in the picture,it is most likely the low press switch so you need to try and locate one and simply unscrew it quick and put the new one on.I am telling you mine did the same thing and when i put the new switch on my problems were solved.You will just have to call around because the switch is on backorder but i was lucky and found one in which i had to take an hour drive to go get.There is almost 1200 orders already for the low pressure switch that the guy at the dealer showed me and 2300 on back order so you can tell this switch is a problem for a lot of people.Chrysler is supposed to get them on August 14 i was told,so you may have to wait a few more days,good luck.

[edsidders]

Another thing to check is the plug-socket where the fan plugs into the wiring harness.. They sometimes develop a bad connection and then burn up/short out..when this happens it can cause a overload in the fan ciruit..Because of the overload the fan relay will cycle on/off . I had this happen to mine,the symptoms were the same as yours..I just cut out the plug and wired it in direct..Be careful and don't get the wires mixed up..Mine must have been a aftermarket fan as all leads from the motor are the same color.Keep us posted on the results.....One of my pet peeves is people not posting results.........

[66CUDA]

Where is the cooling fan circuit relay on a 2006 PT?

[edsidders]

Originally Posted by 66CUDA

Where is the cooling fan circuit relay on a 2006 PT?

I have no idea , on my 01 it is in the fuse box below the master cylinder...

[66CUDA]

Fuse box is still there but the relays were placed elsewhere. The sticky post for '06 PT's shows it in trhe fuse box like your '01 but its wrong.

66CUDA