12 Valve 2nd Gen Dodge Cummins 94-98 Discussion of 12 Valve 5.9 Liter Dodge Cummins Diesels with P7100 Injection Pumps

A/C Only works at Idle

Thread Tools
 
Search this Thread
 
Old Jun 13, 2014 | 10:16 PM
  #1  
DC_DC41's Avatar
Thread Starter
|
Diesel Fan
Joined: Feb 2010
Posts: 23
Likes: 1
Default A/C Only works at Idle

I have been doing some searching and can't find a solution to my problem. When the truck is in park idling and the truck has warmed up the A/C works great, but as soon as I move it/increase the RPM's it just blows the same amount of heat no matter what temperature setting is selected. All of my position selections work also. Any help would be appreciated.
 
Reply
Old Jun 14, 2014 | 10:11 PM
  #2  
4x4manonbroke's Avatar
Diesel Bomber
Joined: Jun 2010
Posts: 3,202
Likes: 143
From: Tacoma
Default

I havent been into one of these.. have you had guages hooked up yet ? what were the pressure's when it was running ?
 
Reply
Old Jun 15, 2014 | 05:59 AM
  #3  
JBearSVT's Avatar
Diesel Bomber
Joined: Oct 2010
Posts: 1,325
Likes: 59
From: New England
Default

Sounds like the clutch on the condenser is slipping. Not saying that's it, but I had the exact same thing happen with a 5.0 Mustang. Changed the clutch, wasn't the issue. Turned out to be a bad wiring harness.
 
Reply
Old Jun 15, 2014 | 09:18 AM
  #4  
4x4manonbroke's Avatar
Diesel Bomber
Joined: Jun 2010
Posts: 3,202
Likes: 143
From: Tacoma
Default

Thats why I asked about pressure's .. if there's no pressure its either the clutch or he has a leak and there's not enough pressure in system to activate the low pressure switch to enguage the A/C clutch ...
 
Reply
Old Jun 17, 2014 | 08:33 PM
  #5  
DC_DC41's Avatar
Thread Starter
|
Diesel Fan
Joined: Feb 2010
Posts: 23
Likes: 1
Default

I have not checked the pressure yet. I will when I can get home in a couple days. Thanks for the help.
 
Reply
Old Jun 17, 2014 | 11:26 PM
  #6  
4x4manonbroke's Avatar
Diesel Bomber
Joined: Jun 2010
Posts: 3,202
Likes: 143
From: Tacoma
Default

yeah, Im thinkin thet the orfice tube or expansion valve is clogged .. your statement about it will work @ idle and the when you giv e the engine RPM's it goes off, makes me think the high pressure switch is cutting out the clutch due to high pressure, or could be low on charge , if you can , get some guages whe you get back and post what you find out, will check back when ya post again ..

Keep us posted...
 
Reply
Old Jun 23, 2014 | 09:16 PM
  #7  
Gcnettl's Avatar
Newbie
Joined: Jun 2014
Posts: 1
Likes: 0
Default

Did you recently "top off" the refrigerant? It could be possible that the head pressure is too high and the high pressure cut off switch is opening. Or by the same could be the low pressure clutch cycle switch acting up. Let's see what happens after gauges are hooked to it. Harbor freight has some on sale for 54 bucks, and they work very well.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Maclain Marsh
Ford 83-94 6.9 and 7.3L General
3
Jul 13, 2015 06:23 PM
tur370
12 Valve 2nd Gen Dodge Cummins 94-98
1
May 17, 2015 04:00 PM
tur370
Dodge Truck and Cummins Turbo Diesel Forum
1
May 14, 2015 08:09 PM
cdetterer
5.9 Liter CR Dodge Cummins 03-07
15
Dec 8, 2014 08:46 PM
JMC23
5.9L 24V Performance
3
Oct 28, 2014 11:03 PM




All times are GMT -5. The time now is 11:49 AM.