If your compressor is making a high pitched sound after turning off the engine, it is the high pressure side bleeding off into the low side

 

I have an 2000 Dodge Dakota V6 and I'm having ac/heater problems. I'm not getting any air hot or cold blowing out, but when I get on the highway a very small amount will blow out. Days will go by and then out of nowhere the blower well start to work and blow perfectly fine on all speeds for both ac/heater for a day or so and then when I turn it off and back on again within the same day it may or may not work. And then the next day I start it up more than likely it doesn't work. And then next month it may or may not do the same thing again. Like one day every 2 or 3 months. Completely random. I've tried buying a new ac/heater control climate/blower/vent switch, but that didn't fix it. Please help.

 

Is the blower turning?

 

When the system does decide to come on it works perfect. It is completely 100% random as to when it is going to decide to work. Last year I tried to turn in on about 50 times and it came on once, but when it did come on the AC can come close to making ice cubes and the heater can warm food. LOL Works like a champ.

 

I've found out that it is the blower motor. Although that within itself is an easy fix, I'm not looking forward to taking apart the entire dash. I was also told that while I'm in there I should also replace the evaporator and heater core. If there is anyone who has done this repair and could share tips and ideas with me I'd like that a lot. And if it is a good idea to replace the heater core and evaporator too even though there is nothing wrong with them at the moment. I'm open to all ideas and suggestions. Thank you very much.

 

Yeah, if you're on the original heater core and evaporator, you should definitely replace them. If you don't chances are you'll be taking the dash out again before too long to replace a leaky heater core.

I just did the heater core (it was leaking) and evaporator in my 99 Durango. It took me a whole saturday to do the job (10am to 6pm or so). I kind of followed the FSM, but after a while just kind of went at it removing stuff as it got in the way. After removing lots of electrical connectors, vacuum lines, and heater/ac lines I was able to tilt the dash back enough to remove the heater box and swap out the heater core and evaporator. Be ready to clean out all the dirt and other crap that's in there.

 

Thank you very much for your input. I'm going to do all three items too. It only makes sense. Take care.

 

I am a new member and was impressed with the knowledge you guys have!
I own a 1998 durango slt and I have had great luck with it. It has 227000 miles with a rebuilt 318 and tranny. Needless to say, lots of stuff needs attention after all this time.
rebuilt the AC module and replaced everything but vacuum motors. All new compressor, condenser, accumulator, evaporator, expansion valve. Put appropriate amount of pag oil and evacuated the system to nearly 29.999 hg. Held that for hour or so. Let system set for an hour at vacuum and no leak noted.
purged gauge lines and then allowed about 6 oz. 134a into system. Started truck, ac on, low fan speed, I then put two 12 oz cans in. Air output temp was 78 f. Gauges read 220 psi high side and 35 psi low side. Outside temp was 91 f. A few days later I noticed the discharge air had gotten colder but it was still low at 71 f and outside temp was 92 f. I then check the high and low side pressures again. Now they are 20ish low 120ish high and compressor is cycling. Outside temp is 70f. I know this thing isn't leaking. So, I add another 12 oz can and the low side line at the compressor is cold and sweating. Pressures are coming up nicely and the discharge air is at 60 f. I liking this trend. I let the system run and the pressures start to go down again. Discharge air remains at 60 f. I can't make these pressures get up even at higher engine rpm. Now I have 4 12 oz cans in this durango and the spec is like 2 cans. ????
the discharge air is getting a little bit colder, (58 f). I feel like I could add another can to get pressures to be correct at ambient outside temperature. How can this be so far off? I feel like I am missing something. Any help would be appreciated!

 

I am a new member and was impressed with the knowledge you guys have!
I own a 1998 durango slt and I have had great luck with it. It has 227000 miles with a rebuilt 318 and tranny. Needless to say, lots of stuff needs attention after all this time.
rebuilt the AC module and replaced everything but vacuum motors. All new compressor, condenser, accumulator, evaporator, expansion valve. Put appropriate amount of pag oil and evacuated the system to nearly 29.999 hg. Held that for hour or so. Let system set for an hour at vacuum and no leak noted.
purged gauge lines and then allowed about 6 oz. 134a into system. Started truck, ac on, low fan speed, I then put two 12 oz cans in. Air output temp was 78 f. Gauges read 220 psi high side and 35 psi low side. Outside temp was 91 f. A few days later I noticed the discharge air had gotten colder but it was still low at 71 f and outside temp was 92 f. I then check the high and low side pressures again. Now they are 20ish low 120ish high and compressor is cycling. Outside temp is 70f. I know this thing isn't leaking. So, I add another 12 oz can and the low side line at the compressor is cold and sweating. Pressures are coming up nicely and the discharge air is at 60 f. I liking this trend. I let the system run and the pressures start to go down again. Discharge air remains at 60 f. I can't make these pressures get up even at higher engine rpm. Now I have 4 12 oz cans in this durango and the spec is like 2 cans. ????
the discharge air is getting a little bit colder, (58 f). I feel like I could add another can to get pressures to be correct at ambient outside temperature. How can this be so far off? I feel like I am missing something. Any help would be appreciated!

 

Sounds like you've got a slow leak.