Welcome To Mopar1973Man.Com LLC
We are privately owned, with access to a professional Diesel Mechanic, who can provide additional support for Dodge Ram Cummins Diesel vehicles. Many detailed information is FREE and available to read. However, in order to interact directly with our Diesel Mechanic, Michael, by phone, via zoom, or as the web-based option, Subscription Plans are offered that will enable these and other features. Go to the Subscription Page and Select a desired plan. At any time you wish to cancel the Subscription, click Subscription Page, select the 'Cancel' button, and it will be canceled. For your convenience, all subscriptions are on auto-renewal.
- Replies 13
- Views 2.4k
- Created
- Last Reply
Top Posters In This Topic
-
Rebelrodder 6 posts
-
MnTom 3 posts
-
LiveOak 2 posts
-
Mopar1973Man 1 post
Featured Replies
Did This Forum Post Help You?
Show the author some love by liking their post!
Welcome To Mopar1973Man.Com LLC
We are privately owned, with access to a professional Diesel Mechanic, who can provide additional support for Dodge Ram Cummins Diesel vehicles. Many detailed information is FREE and available to read. However, in order to interact directly with our Diesel Mechanic, Michael, by phone, via zoom, or as the web-based option, Subscription Plans are offered that will enable these and other features. Go to the Subscription Page and Select a desired plan. At any time you wish to cancel the Subscription, click Subscription Page, select the 'Cancel' button, and it will be canceled. For your convenience, all subscriptions are on auto-renewal.
Hey gang! I'm having issues with the A/C system in my truck. This may take a while and make a long post but I think the context and symptoms may help the diagnosis. About a year ago when I'd turn the A/C on there would be a light smell coming out of the vents. It smelled to me like poplar leaves in the fall after they come down mostly dried up. SWMBO though it reminded her of old books bound in the 1950s and stored together in a closed room. It didn't linger long, maybe a minute or two would clear it out and all would be well. A/C performance was good at this point. I was thinking that maybe I had some poplar leaves down in the cowl that I needed to dig out. Never got to that part... I now believe that this smell is the PAG oil used to lubricate the compressor. Fast forward to a few weeks ago and we got a nice hot spell again and I hopped in the truck to go home from work and wouldn't ya know? No A/C! Drat! I've been reading a lot about A/C systems as this is the first one I've had an opportunity to work on. I'm pretty sure I have a dead evaporator and very low refrigerant level. Here's what I've seen so far: 1. A/C clutch cycles rapidly when A/C controls activated but no cold air is produced. Evidence of a bad Low Pressure Switch or low refrigerant level. 2. Tested the low pressure switch (LPS) per the procedure from the FSM. Switch checks out OK, but exhibits opposite behavior than is expected; no continuity when the compressor is on but there when compressor is off. I think this indicates that the suction side has high pressure when off but low when on, indicating a low charge of refrigerant. 3. High pressure switch checks out OK. 4. When the LPS is bypassed with a jumper wire so the compressor runs the condenser inlet gets quite warm. I don't have a way to measure how warm but it's hotter than you want to stick your finger on. At the same time the condenser outlet line is ambient temp until the rear edge of the passenger side battery. At that point it abruptly turns ice cold and begins to collect frost on the the length of the line all the way back to the firewall. Still no cold air. Seems like there may be a clog somewhere but how would that happen on a system that's never been touched? 5. I borrowed a set of gauges from Autozone. They looked brand new but I wonder if they had issues. When I connected them to the truck in the proper manner I could not get a pressure reading of any sort on the high side or the low. According to the gauges, there was no pressure at all whether the compressor was running or not. When I disconnected the hoses and broke the setup down for storage there was trapped pressure in the hoses that escaped and made me jump. Was not expecting that! LOL Clearly, there is something trapped in the lines! I cannot find any evidence of leaks under the hood based on the notion that a refrigerant leak would also carry the PAG oil with it and leave a stain on a leaking fitting or damaged line. This leads me to believe that the evaporator in the cab is the culprit. I would like to be sure before I go tearing into that particular can of worms. Is it possible to have a leak in the evaporator that releases enough R-134a out to prevent cold air making but keeps enough in the system to chill a line to ice maker level? This seems contradictory to me. Does anyone know off hand what PAG oil smells like? Buying some from the parts house just to smell it seems like a waste of money to me since I will not be performing my own recharge. That is one task I will hire out to an expert! Thanks in advance!