DODGE RAM FORUM banner

1 - 20 of 28 Posts

·
Registered
Joined
·
3,480 Posts
Discussion Starter · #1 ·
Hey y'all- been a while... had myself on social media absence for a while.
but now, I have to ask something. I know about how a air condition works- but with this electronic crap- I'm just too old.
My problem- after it finally warmed up and I used my air condition, I noticed, when I crank the truck up, it gets cold- then, after a mile or so, the air gets warm- like no ac at all. I tried to turn the AC on and off- sometimes it starts back up, sometimes not. And then, suddenly, after maybe 10 or 20 miles, it comes back on. Sometimes messing with the switches works, but more not that work.
The blower works. The problem is- when I drive, I'm on the interstate- so I can't stop and see if the e-fan works- I noticed at home, as it did not work, that both lines were hot. I thought, maybe because lack of gas- it's a 2014 and I never filled it up- so I bought a bottle and i noticed, if it works, the air is much cooler- so there was some missing.
Also what I noticed- I replaced about a year ago the blower motor under the dash. I am actually too lazy to mess with it- but i noticed, when I turn it on full blast, the motor cuts off and I have to turn it off and on to a lower setting and it works. I also noticed, the AC more likely turns warm when I turn the fan on higher than 3 on my switch.
All in all a very weird thing- I believe, if the fan would be faulty, it would make noises and I would notice it- but it was running as the ac was warm and I checked. Also the compressor clutch was engaging fine. From this point, I don't believe a relay or the fan could be faulty- the blower motor is an aftermarket part from Autozone.
Does anyone has an idea? I know sounds weird- but I don't know how else to explain it. Thanks!
 

·
Registered
Joined
·
668 Posts
The fan stops working, which in turn the evaporator starts to ice/freeze up, leading to no cool air . It trips the high pressure switch, after it thaws it resets and turns back on. Either blower motor is bad and or resister.
 

·
Registered
Joined
·
3,480 Posts
Discussion Starter · #3 ·
The fan stops working, which in turn the evaporator starts to ice/freeze up, leading to no cool air . It trips the high pressure switch, after it thaws it resets and turns back on. Either blower motor is bad and or resister.
Thanks for the response- so- which one- the fan at the radiator or the blower motor under the dash?? Thanks for the explanation.
 

·
Registered
Joined
·
1,238 Posts
Sounds to me like you have a possible refrigerant charge issue. Now there could be a blockage which would freeze up an evap and then after it thaws it gets cool again. Need to know what the pressures are to start with.
 

·
Registered
Joined
·
3,480 Posts
Discussion Starter · #6 ·
Under the dash.
Thanks, I guessed it- just wanted to make sure- Yesterday I tried, after your comment and yes- when I turn the blower motor over 3 to 4, the AC runs for another minute and then gets warm. Guess, I have to try a new, insanely expensive, original motor... Thank's a lot - I will keep you updated- guess they have to order it.
 

·
Registered
Joined
·
3,480 Posts
Discussion Starter · #7 ·
Sounds to me like you have a possible refrigerant charge issue. Now there could be a blockage which would freeze up an evap and then after it thaws it gets cool again. Need to know what the pressures are to start with.
Thanks- but not really- when it happens, the compressor runs and both lines are hot- all the way to the expansion valve- if there would be a icing, it would melt in a heart beat- I did not have a gauge- but according the gauge at the bottle I filled in, when it runs, it's in the green on the low side and if not, it goes into high range- which is normal, when they gas pybasses the expansion valve. I also noticed, it must have anything to do with the blower motor, as the AC blows warm when I turn the blower motor up over 3. and then it stays off and comes on after a while, when I turn the blower motor either off or on low- 1 or 2. I just did not think, that the blower motor could have anything to do with it. I will try a motor, I guess...
 

·
Registered
19 RAM 1500 5.7 Etorque. Falcon Wildpeak AT3W/ JMS PedalMax/weatherTech TechLiner/Gator Quad fold
Joined
·
473 Posts
Thanks- but not really- when it happens, the compressor runs and both lines are hot- all the way to the expansion valve- if there would be a icing, it would melt in a heart beat- I did not have a gauge- but according the gauge at the bottle I filled in, when it runs, it's in the green on the low side and if not, it goes into high range- which is normal, when they gas pybasses the expansion valve. I also noticed, it must have anything to do with the blower motor, as the AC blows warm when I turn the blower motor up over 3. and then it stays off and comes on after a while, when I turn the blower motor either off or on low- 1 or 2. I just did not think, that the blower motor could have anything to do with it. I will try a motor, I guess...
Empty some of the refrigerant (too much in the lines can cause a blockage without icing up) if that still doesn't work... empty all refrigerant and refill while keeping an eye on the pressure. Thats where you want to start as those are the cheapest options/tests you can run.
 

·
Registered
Joined
·
3,480 Posts
Discussion Starter · #9 ·
Empty some of the refrigerant (too much in the lines can cause a blockage without icing up) if that still doesn't work... empty all refrigerant and refill while keeping an eye on the pressure. Thats where you want to start as those are the cheapest options/tests you can run.
Thanks- the ac never was filled in 7 years. I assume there was more less than too much gas in it. I filled it up with a half bottle and it still does it. When I leave the blower motor on 2, it works. When I turn it on 3 or higher, it cuts off. Figured that out now. I called the dealer and just refilling is $90+ tax. If I would still work at a dealer, that's the first thing I would had done. Free of charge.
I just don't work on cars anymore for 15 years now. I guess technology passed me by now.
 

·
Registered
19 RAM 1500 5.7 Etorque. Falcon Wildpeak AT3W/ JMS PedalMax/weatherTech TechLiner/Gator Quad fold
Joined
·
473 Posts
Thanks- the ac never was filled in 7 years. I assume there was more less than too much gas in it. I filled it up with a half bottle and it still does it. When I leave the blower motor on 2, it works. When I turn it on 3 or higher, it cuts off. Figured that out now. I called the dealer and just refilling is $90+ tax. If I would still work at a dealer, that's the first thing I would had done. Free of charge.
I just don't work on cars anymore for 15 years now. I guess technology passed me by now.
I don't blame you one bit.
 

·
Registered
Joined
·
1,238 Posts
I might be wrong here, but the high side should be hot until gets to expansion valve. Past that should be cooler, even going back to compressor should be cooler than high side.
 

·
Registered
Joined
·
1,238 Posts
I might be wrong here, but the high side should be hot until gets to expansion valve. Past that should be cooler, even going back to compressor should be cooler than high side.
 

·
Registered
Joined
·
3,480 Posts
Discussion Starter · #13 ·
I might be wrong here, but the high side should be hot until gets to expansion valve. Past that should be cooler, even going back to compressor should be cooler than high side.
Not when the bypass is open. And there I don't know- back in my time it was a temperature regulated mechanical system. No idea how they do it today. I read that the resistor in the fan also turns the ac on and off and if it's broke it actually "tells" the ac it's off even though it's running. That sounds logical.
 

·
Registered
Joined
·
1,238 Posts
I will try to look today in wire diagrams. But usually if fan runs, fan is good. Speed control is via resistors and probably a module by now.
 

·
Registered
Joined
·
3,480 Posts
Discussion Starter · #15 ·
I will try to look today in wire diagrams. But usually if fan runs, fan is good. Speed control is via resistors and probably a module by now.
The fan runs- it's the blower motor inside. It even cuts off on high by itself. Fan clutch engages, all is fine.
 

·
Registered
Joined
·
1,238 Posts
Module control. Also if ac compressor is running engine electric fan should be to.
 

·
Registered
Joined
·
3,480 Posts
Discussion Starter · #17 ·
Module control. Also if ac compressor is running engine electric fan should be to.
it does. Also, when the AC does not cool inside- compressor running and fan running. That's why I'm so confused.
 

·
Registered
Joined
·
1,238 Posts
Check line going from evap to compressor. Should be cooler. If not no flow thru evap/expansion vlv-tube.
 

·
Registered
Joined
·
3,480 Posts
Discussion Starter · #19 ·
Check line going from evap to compressor. Should be cooler. If not no flow thru evap/expansion vlv-tube.
when it cuts off, it's the same temperature- hot, for what I know- it does not go through the expansion valve and directly into bypass. does the expansion valve has a electric valve?
 

·
Registered
Joined
·
1,238 Posts
Could be expansion valve, which to my knowledge is thematically controlled (cant say as I have seen an electronic valve) Or could be an orfice tube in which case it basically a narrowed down restriction to cause a pressure differential as refrigerant comes out the other side. Is it a manual or automatic type system. Do you set temp in controller or just have blue marks for colder. OK just looked in tech data, it expansion valve.
 
1 - 20 of 28 Posts
Top