A/C Warm on Startup

[JBlakeman]

Hey all, have a issue that I haven't found a solution on the forum...



When I first start the truck (warm or cold start) and don't move (i. e. leave it in Park and let idle); the A/C compressor does come on and seems to cycle appropriately however the air out of the vents is lukewarm (a hint of cool) and it seems the clutch fan stays on low speed (no rush of air in engine compartment).



Now as soon as I take off to go anywhere (regardless of driving in parking lot or out on the road... ) the A/C starts getting nice and cold and the clutch fan is heard at every stop. Then if I place into Park and let idle the clutch fan stays on high (constant wind roar under hood. )



I've had the evaporator replaced a few years ago along with the blend door debacle due to a slow leak and air stuck coming out the vents... .



I'm assuming a pressure issue at startup that is resolved once underway however don't know where I should first look... .



Advice please?



Jon

 

[07 ThunderRoad]

If this problem started after the last repair, then my best guess is that there is air trapped in the condenser causing high head pressure that the compressor can't overcome until the truck is moving or you have the engine at 1,000 rpm or more. I just worked on my ac and found that my ac was running high head pressure. Never noted this problem because it usually does not go over 90* here in NE Ohio. Now that it is fixed, my truck is cool and comfortable in 98* heat. This has been on of the hottest June here in Ohio.

 

[Nigel]

I'll bet if you look between the condensor and the rad you will find the front of the rad plugged with crap. When that happens the fan can't pull air across the condensor at idle. Try flushing the dirt out with a garden hose from the fan side of the rad. To do a good job you usually have to pull the rad out of the truck but I've had good luck with just the garden hose myself.



Nigel

 

[sag2]

On my 2003 I recall the cooling fan did not activate with the A/C on a cold start until the coolant temp came up to about 150 degrees. There was a flash that fixed it but looking at the TSB's I don't see anything that matches up. When you cold start it does the compressor come on, then cycle rather quickly?

 

[JBlakeman]

Thanks for the replies so far... .



Actually the clean of the radiator's I performed about a month ago during my oil change. I used simple green and my pressure washer on it's lowest setting and did both the condensor side (up front with all the insects... ) and the back side behind the fan shroud. Looked pretty clean to me... .



Sag... . when I bought the truck years ago the A/C even before the evap. service both the compressor and clutch fan came on and went to high speed no matter coolant temp. Actually could hear the fan "roar" even more then - then now... .



When I activate the A/C these days the compressor clicks on right away and seems to cycle normally (not clicking on / off / on / off like it was before the evap. service... ).



The dealer last serviced the A/C so assuming they put the correct amount of freon in the system.....

 

[Bob4x4]

On my 2003 I recall the cooling fan did not activate with the A/C on a cold start until the coolant temp came up to about 150 degrees. There was a flash that fixed it but looking at the TSB's I don't see anything that matches up. When you cold start it does the compressor come on, then cycle rather quickly?

That tsb is 18-003-04

 

[Bob4x4]

The tsb can be veiwed here

TSB 18-003-04

 

[JBlakeman]

Bob... thanks for the TSB. This does match based on engine serial number and build date however I don't have a fuel guage problem or a California emissions truck which I think this applies to...



Also no cycling issues with the compressor and the system starts working well before it reaches 170F. I've checked my VIN and don't note this particular TSB on file for my truck.

 

[AH64ID]

With your Smarty the TSB shouldn't apply; however when was the last time you updated your Smarty?

 

[JBlakeman]

I always wondered whether or not when the Smarty updates the ECM it also updates our trucks with all the latest "TSB updates" as released by Chrysler without having to "return to stock" than have the dealer perform the update at their hourly labor rate.



Anyway, I have the S06-PoD with the latest software loaded "S06PV411E-URS01B".



Also... another "weird" issue is my HVAC blower fan won't turn off with the ignition... . I now must manually turn off the blower fan after shutting down the truck.....

 

[AH64ID]

Smarty uses the lastest Chrysler software in it's tunes, so you are good for the TSB.

Does anything else stay on?

 

[JBlakeman]

From what I can tell... no nothing else stays on. Windows, Radio, instrument panel all shut off. I've been using A/C nonstop in this hot streak so I've always made it a habit of turning off the fan control before getting home to equalize the system. This morning during my errands I inadvertently left it on after shut down and still noticed air coming out of the vents... . therefore the issue



I'm glad I didn't just hop out and come back later to a dead battery or something worse from it continuing to run.....