Wierd Heating in LS v6

[bwv2k]

I have an o1 LS V6 with a strange heating situation. Here it is: When I turn the heat on in my car the drivers side blows hot but the passenger side blows cold. I put a brand new, not used, DCCV and bled the cooling system per instructions for bleeding LS. Here is the strange part, if I close the drivers side vent and have only the passenger sid vent open, turn the heat to 90 degrees and drive the car for some distance it blows hot air out of the passenger vent. But once I turn the heat down to say 85 degrees it stops blowing hot air out of the passenger vent and only blows cold air. So, in short, when I turn the heat on hot air blows from the drivers side and cold air from the passenger side.

 

[tigapaw]

i feel your pain. i put on 1 from autozone and it failed 1 from advance and it failed.
put on a motorcraft and it's still humming.

 

[joegr]

The heater core is a dual one. Apparently, in your case, coolant is only circulating in the driver's side core. (If you stop the airflow through the driver's side, enough heat will transfer over to the passenger side to get some heat out there, as long as the driver's side valve is open. (Putting it on 90 will keep the valve open no matter what happens, but on 85 it will close the valve if the driver's side is hot enough.)

Since you have coolant circulating in one side (driver's) there's only four possibilities for why it won't circulate on the passenger side.

1. Some issue with the DATC or its sensors. Unplug the electrical connector at the DCCV. If you now get full heat on the passenger side, then you know there is some fault with the DATC.

If that didn't give you full passenger side heat...

2. The hose between the DCCV and the passenger side of the heater core is plugged. Another member found that a previous owner had put wooden plugs inside his heater hoses instead of replacing the DCCV.

3. Your brand new DCCV is defective. You could temporarily swap the driver and passenger hose connections to the DCCV to see (you would then get passenger side heat and no driver side heat).

4. The passenger side of the dual heater core is clogged.

I think that possibility #3 is the more likely one.

 

[bwv2k]

Thanks for all the replies. I will start with the DCCV connection first.