A/C issue blowing hot. Not DCCV.

[Kulow]

Ok, think about the times that you have raced another vehicle or accelerated quickly to get past someone....you know how your a/c dies down and blows warmer than usual then slowly comes back ice cold?

That's the problem im facing....minus the rapid accelerating. It will be cold then it will slowly lose its cool feel and get warmer like i just have the fan on, then a bit later will come back cold.

My brother mentioned something about an ac pressure regulator or something to that extent. Anyone know what I may be referring to?

I know I need to replace my DCCV cause those symptoms popped up a few months back but went away, but this doesnt seem to be the same issue or symptoms as the DCCV going out. IMO.

Thoughts?

 

[scjmc]

If the evaporator is freezing up you will have these symptoms. After freezing the compressor will shut off because pressures get to high, and the evaporator fins don't effectively cool the air because the gaps are closed with frost. Poor airflow past the evaporator might cause it to freeze up also. You could have a blockage somewhere in the system also. If you are lucky you just need refrigerant and the symptoms are unusual.

 

[eastcoastLS]

my a/c started blowing hot air about 30 seconds after a coil completely failed in the middle of cruise control..

 

[tireman]

Just a thought

I torn down the DCCV and found that the water pump supplied the input pressure to it. The valves are solenoid/spring tension operated. If the springs are old they may lose their strength and the water pressure from the racing water pump may actually open the valve and let hot water go to the heater core. Just a theory. I wrote a report with pictures of the DCCV is you need it.

 

[Sn8kbordin]

What is DCCV?

 

[tireman]

Dccv

Dual Climate Control Valve, a common problem unit device, the climate control system will send cold air out one vent and hot air out another. Very frustrating. But this is the culprit. On my 01 V6 it is located on right front engine compartment before the radiator. It just sits there with 5 hoses plugged into it.

 

[Sn8kbordin]

Dual Climate Control Valve, a common problem unit device, the climate control system will send cold air out one vent and hot air out another. Very frustrating. But this is the culprit. On my 01 V6 it is located on right front engine compartment before the radiator. It just sits there with 5 hoses plugged into it.

That is exactly what is happening in my car. Its not bad on short trips, but after 30mins or so, my passenger is in sauna. It is cold here so I didn't notice this until recently.

So I just gotta swap DCCV to a new one?
What is the procedure like on 01 V8 LS?

 

[eastcoastLS]

That is exactly what is happening in my car. Its not bad on short trips, but after 30mins or so, my passenger is in sauna. It is cold here so I didn't notice this until recently.

So I just gotta swap DCCV to a new one?
What is the procedure like on 01 V8 LS?

Next time your car starts doing this, hold the off and floor buttons then let go and press auto. Wait for the 25 countdown to complete then try the ac again. Worked for me.

 

[Sn8kbordin]

Next time your car starts doing this, hold the off and floor buttons then let go and press auto. Wait for the 25 countdown to complete then try the ac again. Worked for me.

I get no error codes (ALL LEDs lit up) after that self test, but passenger still does blow hot air no matter what setting it is set to.
It starts doing that after about 30min or so. At the begging it can blow cold air, even when car reaches operating temp.

 

[srhotz]

Procedure to replace DCCV

I looked at AllData today at work and found the procedure to replace the DCCV. It's located as described above - front-right, near radiator. It's got four (4) hoses, one inlet, two outlets to the two sides of heater core, and one other return which is used for flow not going to the core. There is one three-pin electrical connector that controls two solenoids. A common Vbatt (12V) is used and two low-side-drive inputs are used to control the solenoids from the HVAC ECU. Test procedure says you should see 13-20 Ohms for each solenoid (1 Amp is common for an automotive switching solenoid in my experience). Coil resistance out of that range (shorted or open) would indicate a problem. There could also be a mechanical problem with the DCCV, or the HVAC ECU could have a problem in it's solenoid low-side-driver circuit or with the 12V supply to the coils. That's all described in detail in the AllData if you need it.

The procedure to replace the DCCV wasn't too long but it started with, you guessed it, drain the coolant. After that you remove stuff (included aux pump which is above DCCV) until you can get at this beast. It did NOT involve removing the radiator but did involve operations from above and below the car. I looked at mine for the first time tonight. You might get at it all from above but I can see where the coolant lines are probably accessed better from below in some cases. The bleed procedure (posted here in tech articles) seems pretty important to follow on assembly to avoid hot spots.

 

[Sn8kbordin]

Is DCCV same as Dual Coolant Flow Valve?
Anyone has a part number for DCCV?
I can't find it online in the parts catalog.

I found this in my CD manual:


«2001 Lincoln LS Table of Contents»
«Group 4: Electrical»
«Section 412-02: HEATING AND VENTILATION»
«REMOVAL AND INSTALLATION»


Valve — Dual Coolant Flow


Removal and Installation

1. Disconnect the battery ground cable. For additional information, refer to «Section 414-01».

2. Drain the radiator. For additional information, refer to «Section 303-03».

3. If equipped with 3.9L engine, remove the auxiliary coolant pump. For additional information, refer to «Pump—Auxiliary Coolant Flow, 3.9L» in this section.

µ 4. Disconnect the connector located at the end of the coolant valve harness pigtail.

µ 5. Note:
The top heater hose has a green identifying mark to match the hose on the dual coolant flow valve. If mark is not visible, identify the hoses for location. This will aid in the correct installation of the hose assemblies.

Note:
Hose assemblies shown with components removed for clarity.

Disconnect the three quick-disconnect couplings from the coolant control valve hoses. For additional information, refer to «Section 412-00».

6. Raise the vehicle. For additional information, refer to «Section 100-02».

µ 7. Remove the coolant valve assembly mounting bolt and the nut.

8. Raise the valve and disconnect the coolant supply and return lines.

µ 9. Remove the bolts and remove the coolant valve mounting bracket.

10. To install, reverse the removal procedure.

l Make sure that the heater hoses are installed in the correct position. For additional information, refer to «Heating and Defrosting» in this section.

l Lubricate the coolant hoses with MERPOL® meeting Ford specification ESE-M99B144-B or plain water only, if needed.

l Check for correct hose installation by verifying DATC system operation.

DEWSCRIPTION:

The dual coolant valves regulates the flow of engine coolant to each half of the heater core. Two electric solenoids, which are individually actuated by the DATC module, are the control elements. The valve contains five ports:




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³ 4 ³ Return coolant from heater core ³ rear face ³
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[clubairth]

Yes. The DCCV (Dual Climate Control Valve) controls the different coolant flows for the passenger and driver. Be aware that the V-6 cars use a different DCCV which has 5 hoses on it. They also DO NOT have the auxiliary coolant pump. Plus the above statement is WRONG, the aux pump is under the DCCV and does NOT have to be removed. Also if the aux pump is not working correctly it can be part of your problem.
You do not have to drain the coolant. I put a drain pan under the front passenger side of the car and just let what coolant drain out as the hoses are unplugged. The 2003-2006 V-8 cars have 3 hoses going to the DCCV, NOT 4 as has been posted! Maybe the early cars are different? One of the hoses is attached to your upper radiator hose. So start by removing the intake air tube assembly. Then take the upper radiator hose off. Then remove the coolant hose that runs from the upper radiator hose to the DCCV. Now you will have enough room to unplug the DCCV. Then slide the two remaining hose clamps back on there hoses. Now unbolt the DCCV. You will have to twist and turn the DCCV a bit to work the two attached hose off. Not bad but a bit frustrating. Now I always use a 12 VDC power source and make SURE that the AUX coolant pumps runs and is quiet. You never can tell when it's hooked up because of all the other noise from the engine/fan. Plus if it needs replacing you have done all the work already. Slide the new DCCV valve in there and hook everything back up. Fill with coolant and bled out the air.

I also changed the thermostat, flushed and changed my coolant at the same time so you may want to start by draining the coolant if this is in your plans.

I took my old DCCV apart after it DID NOT fix my problem. They normally fail because the seals let coolant leak into the solenoids and the corrosion starts making the valves stick or not work correctly. Mine was full of coolant but had only just started to corrode the coils.

Further information on my problem. I also replaced the DATC. The in-dash control unit which in the GEN II LS requires programming after replacement. This also did not fix my problem. The Ford dealer ran all the IDS tests but the rest of the system checked out fine. I am considering changing the in-car temperature sensor. This is the one behind the air intake port to the right of the steering wheel. It's cheap and as long as it reads within the correct resistance ranges will not throw a code. If it is changing slowly or not at all, it might be the problem.

You can get the DCCV from RockAuto BUT they call it a heater control valve. It's $100 and is part number Motorcraft YG-378 (For the 2003-2006 cars). A BUNCH cheaper than Ford. I also recommend using ONLY Ford thermostats. I got the wrong one twice for my 2003. The early cars 2000-2002 use a conventional thermostat and you can get one at any after market parts place.
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Please post back when your problem is fixed, I would be very interested!!
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[Sn8kbordin]

the instructions I posted were for 2001 LS from a CD manual