2nd Gen Non-Engine/Transmission Air Conditioning(or lack thereof)

[dshatzer]

I have been looking for a thread, and or helpful information, that addresses occasional A/C functioning. Our 1998 12v seems to have a complete charge (per inexpensive auto store gauge), the compressor cycles every 20-40 seconds, the line to the passenger compartment is frosty cold, but no cold air in the cab. It started as an intermittent problem, and now is hte status quo... . Not what the spousal unit expects from her truck..... Just looking for suggestions, as I have not had time to find a solid HVAC service center. Thanks for the replies.

 

[The patriot]

Your coil may be clogged. ~If it is:

This is not a job that can be described on the computer.

From what I'm told, the whole dashboard pretty much has to be taken apart.

Not an easy fix. :{

Hope that this aint it.

Eric

 

[jimk]

Is the suction back to the compressor cold? The compressor is cycling every 20 to 40 seconds on Max? Do you have a fan in frount of the condensor coils when testing the unit? Is the unit low on refrigerant. Does the truck get cool at idle an when you speed up nothing.

Has some one added a lot of oil to the system. I have blow out trash with a washdown gun and MEK in systems that have bad compressors or a dryer has gone bad. Good luck Jim

 

[dshatzer]

Don't know about the suction back being cold, but it does cycle 20-40 secs on max. It doesn't get what I call "cool", or cold at any engine speed. No fan in front of condenser, as ambient was only 74F. Thanks for the ideas. The codenser looks good. My concerns are a bad dryer, or evaporator clog. Is there a door in the heater box that could be blocked by a dead critter ? At least it's towards the end of the cooling season.

 

[Dan_69GTX]

Sounds like it COULD BE the "blend door". Check out

https://www.turbodieselregister.com/forums/showthread.php?t=101795&highlight=heat*+doo*

which deals with that issue.



If your system has never been apart the chance of a bad drier is almost nill. The only thing that can go "bad" is the descicant bag will deteriorate and allow the descicant to block passages. However, you said the line into the evap was cold, so that can not be the case.



If the blend door isn't the problem you will need to know high and low side pressures to start any other problem solving - knowing if any work has been done to the system will help too.



Dan

(Yes, I repair a/c systems).

 

[CFAR]

isn't there a filter in between the dryer and evap?

 

[Dan_69GTX]

On the older systems where an expansion valve is used, yes, it can be called a filter - but in reality it is a drier/receiver. It doesn't have any filtering capabilities.



On the newer trucks that have an expansion orifice, it is called an accumulator and is located AFTER the evap. This way it can collect any liquid refrigerant that exits the evap. The compressor "doesn't like" liquid refrigerant.



An evaporator is typically larger than a drier/receiver.



Dan

 

[CFAR]

I just remember on my 96', I replaced a 2 1/2" long plastic piece that slipped into the pipe that goes into the firewall. and it was called some type of orifice. If I remember correctly it had some fine screen in it.

 

[jimk]

The screen on the orfice is just to catch trash. I have had problems with AC systems and if the system has not been opened up or a leak I have to go with the dryer not being bad. But if you have ever had a bag of the descicant come apart you will not forget it soon, ( bought a used car).

I have gotten ac systems to cool better by shutting off the heater lines. That may not be a popular idea, but it has helped me before.

If you have the proper charge and no restrictions in the system I would check the ducts to be sure you have proper air flow. I am not sure about not but years ago I was told to use a fan to help simulate air flow when moving in front of the condenser. The like to have a cold line back to the suction of the compressor when I am checking the system. good luck Jim

Good luck Jim

 

[Futures1]

Hey Jim. . I had a similar problem recently. . (but, the outside temp. was quite hot),

Anyway, very little cold air coming from the vents. . checked it with a temp guage and it was only cooling down by 10* . I also checked the pressure with a guage and it seemed to be right up there. I purchased a small can of freon, (2 oz, with dye in it), shook it up and dumped it in. Problem solved !!

 

[Rob Levandoski]

My 2000 had no A/C so I finally decided to fix the problem. Recharged the system and lost A/C within 2-days. Long story short - - removed the entire interior dash and replaced the A/C condensor (sits in front of the passenger). Took almost 2-days to tear down and replace.



Not sure if this is your problem but the replacement had led me to have cold (brrrrrr) A/C. My passengers are also thankful.

 

[dshatzer]

Dan, Thanks for the advice. System has never been apart. Truck has 125K miles. I will look at the box under passenger dash. Still looking for reliable A/C shop in Frederick MD area.



Dave Shatzer

 

[Dan_69GTX]

Your welcome,



Hope you can find a reputable shop. Not finding one is why I bought all updated equipment for doing a/c work. (I keep telling the wife that this is just a hobby ). But all my tools have paid for themselves, even if it did take a little while.



Please post what is found to be the problem - would be interesting to hear. The OEM service manual should help with checking the operation of the blend door.



Dan

 

[nopowerforme]

Dan, Thanks for the advice. System has never been apart. Truck has 125K miles. I will look at the box under passenger dash. Still looking for reliable A/C shop in Frederick MD area.



Dave Shatzer

Not sure if this will help but I have a 1995 and from the day I bought it I had trouble with the A/C and I bought it used... in 1998 sometimes the A/C worked but most times it did not... had it to several different shops, had it charged, flushed, dye added several times no one could ever find a leak, one guy said the condenser was bad $400 for that so i passed it up the compressor would cycle on and off but rarely ever stayed on for long I finally took it to a dodge dealer in Harrisonburg VA and they told me my clutch was wobbly :>) and they said I had a leak... they also said there was a switch on the left side of the engine near the front down low that was not making contact all the time. . they taped it up Viola ... . I left there with A/C and still have a/c three months later gets down to 40 degrees coming out of the vents. YAHOO!!!!! All those years with no A/C and now I have it.

 

[dshatzer]

Sorry for the delay in responding, however, work sometimes gets in the way of life and desel rtepairs. A/C problem was... ..... yes... . the Evaporator... No, I did not do it myself, because it would have taken another 2 months to complete, but it is now fall and I have snowfall from the vents. My thanks to all...



DS