'00 V6 New DCCV but cold driver side and hot passenger side problem persists

[TomPJr]

Team,
After a rather difficult replacement of the DSSV to try to resolve cold AC on the driver's side but full hot heat on the passenger side, the new Motorcraft DSSC did not do the job. WHile I was in there, I cleaned all the electrical connections and made sure the electrical plugs were seating well. I am not sure where to turn next. Has anyone encountered this?
Tom 2000 LS V6

 

[joegr]

You'll have to run the pinpoint tests to test the wiring between the DCCV and the DATC, and to test the DATC itself.

 

[TomPJr]

Excuse my ignorance. What is a DATC? I can build an E-Type Jaguar or an MGA from scratch, but the LS is new to me. Tom

 

[RigsLS]

See Joe's response here http://www.lincolnvscadillac.com/fo...No-heat-Thread&p=904273&viewfull=1#post904273

DATC = Dual Automatic Temperature Control module




Check fuse #1 underhood

Perform the DATC self test, it's in your OM which you can download from the Tech Section in the top bar from this site.

 

[TomPJr]

Thanks BigRigLS. I found the procedure (Key to On, Off and Floor press simultaneously...). The system diagnostic clearly ran, as the unit was counting upward various sequences of numbers while I could hear all forms of damper/doors in the dash operating. At the end of the diagnostic cycle, all of the LED characters on the control screen illuminated, but there was no error code. I also checked the #1 fuse and it was fine.

So, I have a brand new Motorcraft DCCV, a good fuse, and no DATC error codes. Yet, I still have hot air on the passenger side with cold AC on the driver's side! Hummm... What next?

I have not seen a diagram of the heater cores in the dash, but I can image one small core for each of the passenger and driver sides. Has anyone ever considered using a hose-pinch to pinch off the passenger side core hose for the summer months, or, if you want to get fancy, install an inline cut-off valve?

THanks in advance,
Tom

 

[joegr]

... Has anyone ever considered using a hose-pinch to pinch off the passenger side core hose for the summer months, or, if you want to get fancy, install an inline cut-off valve?

THanks in advance,
Tom

Or, you could fix the problem and have it operate correctly. It seems like that would be more convenient.

1. Your new valve is bad. - It does happen.
2. Your wiring to the valve is bad (less likely since the self tests passed).
3. Your DATC is bad.

With just a multi-meter and a little bit of time, you can determine which of the three it is.

 

[TomPJr]

Joegr, is there a procedure posted for testing the valve and the DATC?
Man, I'd hate to replace that DCCV again - that was a very unpleasant job; driven highly by the tough location and the nearly impossible constant-pressure hose clamps magically positioned to be unable to get the clamp pliers on them.
Tom

 

[joegr]

Let's start with this.
With the engine running and the AC on, measure the voltage between the red wire with orange stripe and the black wire with orange stripe, at the DCCV. Then repeat for the red wire with orange stripe and the brown wire with green stripe. If you get 12V to 14V each time (and the passenger side is heating), then your DCCV is bad.

Do note that if the refrigerant system is a little low, you will lose cooling on the passenger side first. I assume this is not your problem, since you say the passenger side is actively heating.

 

[RigsLS]

... making certain the hoses went back on in their respective locations to the DCCV

 

[RLFlynt]

Let's start with this.
With the engine running and the AC on, measure the voltage between the red wire with orange stripe and the black wire with orange stripe, at the DCCV. Then repeat for the red wire with orange stripe and the brown wire with green stripe. If you get 12V to 14V each time (and the passenger side is heating), then your DCCV is bad.

Do note that if the refrigerant system is a little low, you will lose cooling on the passenger side first. I assume this is not your problem, since you say the passenger side is actively heating.

Joegr,

Sorry to jump on this old tread, but it is the only one that fits with my issues after searching the sticky's and rest of forum. I have followed this forum for a long time and thanks to all of you guys for helping me keep my sanity with this car. You mentioned that if the Freon is low it would have the same affect as a bad DCCV with cold/cooler air on driver side and warmer air on passenger side. I have replaced the DCCV (Oh what fun on a V8), but it may need a new one again. I have used hose pinch pliers on the 2 DCCV hoses at the fire wall (Do I need to pinch all 3?) which did not make any changes to the original air temperatures from the vents as check before crimping hoses (Other than it will not adjust to hot when selected) I would assume that this is a test to verify that the DCCV is indeed bad and stuck in the open position and would stop all hot water from circulating through the heater-core. So if these are blocked and I am still getting warm air from passenger side it would indicate a HVAC issue such as low of refrigerant?

 

[joegr]

Warm as in not well cooled, but not hotter than outside air?
Do you hear a sort of hissing noise in the dash for a few seconds when you turn the AC on?
If so, then it probably is low refrigerant.

 

[RLFlynt]

Warm as in not well cooled, but not hotter than outside air?
Do you hear a sort of hissing noise in the dash for a few seconds when you turn the AC on?
If so, then it probably is low refrigerant.

Thank you for the quick reply. Yes warm as in cooler than outside air about 15 degs warmer than the driver side which is cold but not as cold as it should be either, I do not hear hissing from dash area (Could be my bad hearing). I will take it in tomorrow as i do not have a set of gauges, and have the shop check the gauges and maybe put some dye in it so i can see if there might be a slow leak somewhere.

 

[joegr]

Be sure that they remove the guard under the compressor and look at the compressor really good to see if it is leaking oil from the scroll control valve at the back of the compressor, or from the fill port.

 

[RLFlynt]

Be sure that they remove the guard under the compressor and look at the compressor really good to see if it is leaking oil from the scroll control valve at the back of the compressor, or from the fill port.

Will do and once again thank you. I want to love this car as much as my wife does, but she doesn't have to work on it.. i do and thanks to a lot of your comments it has made it a lot easier.