DCCV fail to full heat?

[Kumba]

So it seems that most of the threads I read about DCCV failure is that there is no heat. Is it possible to fail full-on?

Was driving around a parking lot waiting on GF to exit store, and suddenly the AC was blowing full heat from both sides. So much for a gradual failure, but does this sound like a DCCV, or should I look elsewhere too?

Thanks for the input.

 

[joegr]

I would say that it is far more common for the DCCV to fail such that you get full heat on one or both sides.

It could be your wiring or your DATC, but it's almost certainly your DCCV. Also note that there is a 10A fuse to the DCCV and AC compressor. A short in a failing DCCV can blow that fuse.

 

[Andrizzle]

This is probably karma for you telling your GF that you would wait in the car.

 

[Kumba]

This is probably karma for you telling your GF that you would wait in the car.

Well I figured that was all cancelled out by me giving her all my money? Besides, last thing I wanted to do was go shopping in a damn Coach store!

The AC compressor works, checked that already. Got a DCCV coming, just making sure I wasn't missing anything.

 

[stihlboy]

mine went to full heat on a very hot day. it sucked

 

[Kumba]

mine went to full heat on a very hot day. it sucked

Yeah, at least mine broke when it's like 60 out, so it's not bad, other then wind noise from having the windows down.

 

[TooManyToys]

Can't you just turn off the HVAC.

 

[joespanova]

OK , so what is it? A failed DCCV causes max heat or no heat..............which one??
My thread indictaes no heat and a failed DCCV has been suggested

 

[joegr]

OK , so what is it? A failed DCCV causes max heat or no heat..............which one??
My thread indictaes no heat and a failed DCCV has been suggested

It can cause both. It depends on how it fails.

Solenoid coil(s) corrode and go open circuit -> Full heat on at least one side always.

Solenoid coil(s) corrode and go short circuit at the power side of the coil -> Full heat on at least one side most or all of the time.

Solenoid coil(s) corrode and go short circuit at the ground side of the coil -> No heat on at least one side most or all of the time.

Valve(s) corrode and get stuck open - Full heat on at least one side always.

Valve(s) corrode and get stuck closed - No heat on at least one side always.

Valve(s) corrode and start sticking - Full heat sometimes, no heat sometimes, and works more or less correctly sometimes.

 

[joespanova]

It can cause both. It depends on how it fails.

Solenoid coil(s) corrode and go open circuit -> Full heat on at least one side always.

Solenoid coil(s) corrode and go short circuit at the power side of the coil -> Full heat on at least one side most or all of the time.

Solenoid coil(s) corrode and go short circuit at the ground side of the coil -> No heat on at least one side most or all of the time.

Valve(s) corrode and get stuck open - Full heat on at least one side always.

Valve(s) corrode and get stuck closed - No heat on at least one side always.

Valve(s) corrode and start sticking - Full heat sometimes, no heat sometimes, and works more or less correctly sometimes.

Thanks again , I appreciate your input!

 

[Kumba]

Can't you just turn off the HVAC.

Yeah, AC is off and windows are down. Only issue I have is the heater core still has hot coolant pumping through it so you still get residual heat. You can feel it coming out from under the dash after you drive for 30 minutes or so. Plus I think the open windows are pulling air through the AC vents.

 

[joegr]

Y... Plus I think the open windows are pulling air through the AC vents.

Yes, it does.

 

[TooManyToys]

+2

 

[jdmans101]

It can cause both. It depends on how it fails.

Valve(s) corrode and start sticking - Full heat sometimes, no heat sometimes, and works more or less correctly sometimes.

Dang it! Having an issue since I just started using the ac for the first time this year. Just replaced the DCCV before winter and pretty sure its taking a crap on me. When the engine is cold the ac will kick on both sides without a problem, It will stay on until I shut the car down. When I turn her back on from coming back from the store or something it then starts blowing heat. Kinda odd I think. I'm just confused with why it works fine until I turn the car off when its warmed up and then quits working.