dccv 2005 ls v6

[tigapaw]

dccv was replaced when it shorted out-got the service ((P)) indictor. a/c worked for a while and would quit.
then would work off and on blowing hot air when not working. let this go for some time and finally started to check it out myself.
when i bled the system myself it had air in it, took awhile but got full stream out the heater bleed valve. all was fine for about a month but now hot air again.
i can not get the system to bleed again, just a trickle but what would cause this after it was bled once.

 

[joegr]

Your post is not completely clear.
If you are saying that you are back to getting hot air when you don't want it, then your new DCCV has failed, the fuse has blown, or the connector to the DCCV isn't plugged in completely.
You may or may not have air in your cooling system, but this has nothing to do with you getting hot air when you want cold. (Air in the cooling system will cause cold air when you want hot and/or engine overheating.) If the system won't pressurize to bleed, then you have a leak somewhere. If there really is air in the cooling system a month after it was all okay, then you have a leak.

 

[tigapaw]

i had advance put a pressure tester on the system and pump it up to 16psi and it held
but only tested it for 2- 3 minutes. how long should you leave it under pressure to see if it will leak down
and yes i am back to getting hot air. heard wiring harness click when it was put on

 

[joegr]

Are you getting heated air, not just non-cooled air?
Does it work correctly for the first minute or two when you first start out in the mornings?

If so, then you have a bad DCCV, the DCCV isn't fully plugged in, the wiring to the DCCV is bad, the DATC is bad, or both outlet air temperature sensors went bad at the same time. This is your list of possibilities. Non-OEM replacement DCCVs have been known to fail as quickly as a month after being installed.

 

[tigapaw]

yes it will work some times and then start blowing hot air. think i'll get the Motorcraft YG378 Heater Valve and start over
i let it go a long time before i did the bleeding my self so this dccv has been in the car not working right for about a year.
when i put this one in i'll check everything out right away myself. thanks for your help

 

[tigapaw]

1 last question - should you flush antifreeze when doing this
last one was put on by clamping hoses and just adding back lost coolant

 

[joegr]

If you haven't mostly changed the coolant in the last three years, then yes you should replace as much of it as possible.