Picked up a 2001 Excursion a few weeks ago. Trying to sort out some of its issues. The rear HVAC seems to only blow one temperature... Luke warm. Front A/C and heat work fine. I checked the temp blend actuator and it seems to work fine. The rear expansion valve gets cold and there is condensation that drips from the rear. Any ideas what else I can check?

 

Put the ac to max cold.... 60 deg. F , then check air exiting the vents again. Let us know if it's still luke warm.

Few things I've discovered... hot coolant travels through the (heater core) unit unless you put your ac control to max cold.

The Heater by pass sucks on the ex and Diesel Site sells a kit that works well for colder ac http://www.dieselsite.com/colderacvent.aspx

If none helps time to e-vac the system and unclog or replace the expansion valve/orifice.

 

Have you checked that the front and rear controls are both set all the way to "cold?"

 

Thanks for the replies!

So I did some fiddling while taking the kids to school in my school bus this morning... When I first turned on the rear AC it blew cool (not cold) for about 15 seconds then went to luke warm. Turning the temperature selector doesn't change the air temp coming out of the vent. If I turn the AC off (by turning the front selector to vent) then the air will blow warm. Seems like I need to do something to block the hot coolant from the heater core unless needed.

Is there a way to block the coolant flow to the heater core to test this theory before buying a valve?

Yes, both are set to full cool.

 

I remember something about the rear blend door located behind the passenger side panel in the 3rd row/cargo area. Search the site, I can't for the life of me remember if something needs to be lubricated, adjusted and that might fix your problem.

 

Thanks! I checked the actuator and it seems to be opening and closing the door. I suppose the actual door inside the duct could be broken

 

With that panel off run the ac and see if you manipulate the blend door by hand if you notice a temperature change. The actuator might appear to work but might be weak after 13 years of service.

 

No change in temp when turning it manually from the outside

 

How hot was the engine at this point? Did you do this as soon as you started the vehicle? If it was at operating temps, it should be HOT not warm
Edit - I am referring to changing the temp selector

 

Is this something that would possibly prevent 2nd row air from coming out vents? First and 3rd row work fine but no air in 2nd row. We can hear it though....

 

Have you had freon level checked?

 

Let us know what you find... when you do.

 

Pulled out the gauges tonight and after letting it run for about 5 minutes low side reads 45*, high side reads 225.




Not running




Running after 5 minutes

To continue diagnosing the rear AC I clamped the rear heater hoses to prevent flow. The system still blows "room temp" so it's not a blend issue. I checked out the expansion valve for the rear and it's cool enough to sweat but definitely not cold, so I think it's the culprit.

The question that remains for me, because I don't quite fully understand dual AC systems: is it possible to have enough refrigerant in the system for the front AC to work but not enough for the rear to work? How would you know if this were the case?

The front AC is starting to struggle as it heats up here in Texas. So I'm thinking it may be time for a AC redo... Compressor, accumulator, orifice tube and expansion valve.

 

My reading of other posts and searching has the expansion valve getting "debris" in the screen and limits the cooling. Of course it's inline with the system so evacuation is necessary.
https://www.ford-trucks.com/forums/1...-a-c-warm.html

 

Starting repair today... Took it to my friend's shop to evacuate the system. It was low on refrigerant (about 3lbs came out of it) so just for kicks he put the recommended 4lb 4oz back it to see if that helped. It did not :-(

So, I took it home, windows down in this lovely Texas heat to start the repair. Decided to start with the compressor... That sucked! Removing the fender liner helped. Took me a while to find the holes through the engine support member that allow access to the bolts. That was helpful.

The accumulator came next for removal... There's two stupid screws behind heater hoses that aren't very movable!!! Finally got those out and it was pretty straight forward after that.

Orifice tube next. Really the easiet part. I found this:



So now I need to flush the line from the condenser to the accumulator... Not sure if I can flush the condenser (seems like the common consensus is not to flush)... Would love advice on that.

Moved on the rear expansion valve... Lower two fittings came off no problem. Upper fittings are being difficult. I have some lubricant on them for the time being to loosen them up. Going to have to get some flare nut wrenches for the top right one since I can't get a wrench in there at all.

Got the accumulator reinstalled. Tried to reinstall the compressor but it's a pain to lift back into position so it's going to wait until morning when it's no 1,000 degrees outside. Any tricks on getting that guy back in place would also be appreciated.