Ac Clutch only engaging from defroster. Could really use some help

dodge
stratus

#1

I just bought a 01 dodge stratus with the 2.4 DOHC. Initially I thought the AC needed a charge, but I put a pressure gauge on it and its holding at 70 lbs on the low side so I figured it was a relay. I replaced the relay, and I started the car. The heater control was on defroster, so I switched it to max AC, and got really cold air.
Here is the weird part. the AC clutch will only engage when you are on defroster, then go to AC, If I were to have the fan off, then start it on AC, it doesn’t get cold. but if I switch to defroster, then back to AC, it will be cold as long as the system is on. Anyone have any ideas how to make it come on from the AC setting on the controller?

I have already replaced the heater control on the dash, the AC relay, and the controlling fuses. Thank you in advance.


#2

Not sure how you tested. Seems pretty high to me. Should be more in the 45-55 range, depending on temperature.


#3

The static pressure of an AC system (system not running) can be anywhere from 75 PSI to 100 PSI.

Depending on the ambient temperature.

Tester


#4

Thats what I thought too, but after researching, the low side and the high side equalized because the guy i bought it from hadnt run it in a while, and the relay needed replaced anyways. Once i did that, the low pressure side tested around 35 psi when the clutch would disengage, then the pressure built up to about 50 lbs before the clutch kicked in again.


#5

Do you have 2 radiator fans? If so does the second come on when you turn on the AC?


#6

I also found when i took apart the Control module that the contacts inside werent making good contact with the board when the dial is set to the Max ac setting. I bent them out a little bit and reinstalled. That didnt fix the issue though.


#7

i do have 2 fans, but i dont notice a correlation between them and the AC system. should I?


#8

Most cars the second fan will kick on when ac is engaged, not sure if second fan failure to engage can disable ac, others here know more than I.


#9

thank you. i will take a look at the fans and when they kick on. I guess i just always assumed that they were for low and high speed, like to prevent overheating the second kicks on when the first cant keep up.


#10

Do you know why I would be able to have the cold air when I quickly switch it to defroster then back? That is how I am “tricking” the system to work now… This “trick” will make the ac work perfectly until I shut off the car or turn off the blower motor.


#11

On your car both fans should come on when you are on “defrost” or one of the “AC” positions.

Edit: After you switch from defrost to AC, do the vent/blower controls still work (dash/foot vents)?


#12

So both the foot and face controls will change where the air is coming out,
but i dont think the compressor will stay on.


#13

Look at the compressor clutch plate and see if it is engaged. For some reasons I have a feeling that you do not have an A/C problem but maybe a problem with the blend doors.


#14

The doors will move after the ac comes on and will stay cold. So really the
only issue is that i have to go all the way to defroster then back to ac
max to get cold air. It basically will work fine until i shut off the
engine or the blower motor