Medium and Heavy Trucks
Have Truck Repair Questions? Ask an Expert
good evening my name is ***** ***** I will assist
it is supposed to cut off at that pressure. what is the low side pressure when it hits 350???
how much freon did you install?? too much freon will cause this
give me any info you can
low side way too high. it looks like it is way overcharged. high side should be outside temp plus 15% and the low side 25-40 lbs max
25-40 lbs on the low side, yes
yes it is. anything below 20 lbs and the system will freeze up. been doing ac for over 35 years
when it is overcharged, the pressures will be too high on both sides like you have according to your post
your words said 3 lbs not sure???????? this was in your post
I am here and not there to check it. you are my eyes and my info and go on that info.
I would start from scratch and remove the freon, vacuum for 30 minutes and add exact amount called for according to the sticker
ok, try hosing down the condenser and see if the pressures drop
so your now saying it is definitely 3 lbs and you are sure
ok, then theres is your issue. have you bypassed the fan solenoid to see if it works???
you replaced the binary switch??
once you get the fan running the pressures will return to normal
I didnot ask if it was new, I asked if you bypassed it to see if the fan works
it ison the passenger side by the dryer. it contains the low pressure and high pressure switch that signals the fan solenoid to engage. you said you already replaced it in your original post??????
ok, I am sorry, I cannot continue. you keep giving me info that is either maybe or not sure and you doubt my pressure readings. I am trying to help and keep finding new info you never indicated. you have not answered whether you bypassed the fan as you said it wont come on. you did not cool down the condenser with water and give me the readings.
without info I cannot help you get to a resolution. I will re post for you and hopefully you will give accurate info to the next guy.
good luck, I hope you get it straightened out.
I can help if you give me the info I request. I new it would drop, what about the low side??? the fan???
ok, go ahead. I am ready
ok, so the fan works and the low side came down. is the air nice and cold now???
ok, if you have a water hose, hose down the condenser on the front of the radiator and see if the high side comes down
good, we are moving in the right direction.
clean out the condenser and the radiator ral good. you may need to use a comb for this. if you dont have it then take it to a car wash and use high pressure wash with hot soapy water to clean out all the fins of debris. not enough air going through radiator to cool down the freon.
then the fan control needs to be dealt with to get the fan working right
52 not bad. was there much dirt in the fins????
can you feel a good draw of air into the radiator with the engine running???
ok, after the pressure wash, is the high side still over 300
it should, the fan needs to run to lower the high side.
have you had the fan checked as to why it wont start on its own??? or do you just turn it on manually
ok, you did replace the fan solenoid?? did you verify power to the solenoid??? the control is the coolant sensor. that signal is sent to the ecm and the ecm will turn on the fan
ok, thats the correct time. so with that in mind the ac still goes high with the fan on???
250 is a good pressure. what does the low side do when it is at 250
still a tad high.
I would start by removing the freon, vacuum for 1 hour and adding exactly the amount needed again
sounds like a plan
ok, which fan??? inside or outside??? what was the temp at the vent???
ok, is that the temp of air coming out the vent or the temp inside the truck??
thats not too bad. it should be around 52. rev the engine up and see if it gets colder.
what are the pressure readings??
ok, got it.
the next thing is the mode door. can you see if the mode door is fully closed for ac and not letting anything from the heater core coming in
should not have to.
yep, I know it is a pain in the butt to get to
what did they do???
you said the ac clutch was activating??? does that mean all this time the clutch was not engaging????
yes, but as you said just now, the clutch was working
anyway. its fixed and glad you are back on the road
good luck to you
once the head pressure gets high, it is supposed to shut down to protest the system. thats what the high pressure switch is supposed to do
yes it was. I read it all. thats what we were trying to get to. it is supposed to do this. that is the problem with me being here and not there to see it for my self and do the actual diagnostic.