Yet another Gen 1 climate control problem/question

twinbopilot

twinbopilot

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I've been reading every post I can find here on Gen 1 climate control issues. So far this is what I think I know:
* There is one a/c system that feeds both the passenger and driver sides
* Each side has its own heating system, controlled by the DCCV valve
* The system controls the temp on each side by blending a/c air with each side's own individual DCCV air
* When the system is placed on 60 degrees "Max Cool", there is a bypass door that opens/shuts to block off any potential hot air blend from the DCCV
* DCCVs get stuck a lot on these cars
* DCCVs can be cleaned instead of replaced (Tireman's instructions)
* The system has a self-test mode that is started by pressing "OFF" and "DEFROST' and the same time, then pressing "AUTO" within two seconds

I showed no codes when I ran the self test.

However my situation is confusing me. When the a/c is running, the driver side gets cold air but the passenger side gets warm air. Even when I crank the temp down to 60 degrees, still warm air from the passenger side.

Question 1 - If the bypass door blocks any hot air from being used, how can I still be getting warm passenger side air when temp is set at 60 degrees?

Question 2 - Does this sound like my DCCV valve is stuck in the OPEN position on my passenger side?

Question 3 - Am I missing something here?

Thanks for your feedback!
 
I would measure the temperature out each side. I'd bet that the driver's side isn't as cool as it is supposed to be either. I suspect that you are low on R-134 or otherwise have an AC system problem, not the DCCV this time.
 
I have one of those infrared temperature scanners. I'm getting 36 degrees out of the driver's side, and 66 degrees out of the passenger side. Ambient outdoor temp is 72 degrees. I only get the warmer air out of the passenger side when the engine is hot. Upon cold start-up, the air is cold on both sides until the engine warms up. Thats why I'm confused - I thought the bypass door eliminated any possibility of hot air when the temp is set to 60 degrees???
 
Found this thread on another site: http://www.automotiveforums.com/t757235.html

Based on what went on in that thread, I'm ordering the evaporator discharge temperature sensor MOTORCRAFT Part # YH1504 {#XW4H19C734BC, XW4Z19C734BA} (Located at Plenum Chamber Assy). Less than $10 from rockauto.com

If your gonna throw parts at it, they might as well be cheap ones. :p

I'll update the thread, but if anyone else has any ideas feel free to chime in...
 
wouldn't this be a good case to "clamp off" the passenger side coolant hose from the DCCV so that you could easily rule it out as a problem, free to test(as long as you have a clamp) and should be able to prove that it is not the problem pretty quick with out taking anything apart.
 
1LoudLS said:
you could also have a problem with the bypass door.
Click to expand...

Yes, but the self-test that he ran should have caught that if so.
I'm still tempted to say check the AC system pressures, or at least check to see if the AC clutch is cycling too much.
 
Gen 1 temperature control problem

About 80,000 miles ago, a "blend door actuator" was supposedly replaced on my '02 LS with similar DTC system problems. Because of warranty coverage, I did not have to do the system analysis like you have done. So this is just a comment. Whatever the dealer actually did corrected the problem.
 
I like the idea of clamping the hose coming off the DCCV. That should tell me if the DCCV is stuck open (I think). Will do it and report back...
 
Its definitely the DCCV. All I did was let the car warm up and feel the two hoses coming off the dccv that lead back to the cabin. They run along the passenger side of the engine compartment. With AC set to 60 degrees, the top one (driver's side I assume) is cold, while the bottom one (passenger side?) is hot. Seems as if the DCCV valve is stuck open on the passenger side. Tireman is emailing me his report on how to clean & repair the DCCV. That will be my next step.
 
twinbopilot said:
Its definitely the DCCV. All I did was let the car warm up and feel the two hoses coming off the dccv that lead back to the cabin. They run along the passenger side of the engine compartment. With AC set to 60 degrees, the top one (driver's side I assume) is cold, while the bottom one (passenger side?) is hot. Seems as if the DCCV valve is stuck open on the passenger side. Tireman is emailing me his report on how to clean & repair the DCCV. That will be my next step.
Click to expand...

It's possible that the DATC isn't powering the passenger valve for some reason, and that would give the same result. That said, the odds are really good that the DCCV itself is the issue.
 
Joegr, you are spot-on as usual. I've seen your postings across the interwebz on this and other sites and I know you are well versed in this stuff.

Hopefully it is just the DCCV - Wouldn't it throw a climate control code if the electrical signals to the DCCV were incorrect?
 
joegr said:
It's possible that the DATC isn't powering the passenger valve for some reason, and that would give the same result. That said, the odds are really good that the DCCV itself is the issue.
Click to expand...

could you meter one of the pins and the harness for the DCCV to see if the signal is being sent or not?
 
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