Not sure how to word this, so I hope this makes sense. When I turn
the heat on the air comes out mostly on the floor. When I turn the
cold air on the air comes mostly out of the dash. Why can't I get
the heat to come out of the dash. Is this the way it is supposed to
work? Can I change something to get the heat to come mostly out of
the dash? Buy the time the car warms up inside my feet and legs
are on fire. Just in case you need to know it's a 85 xjs v12.

Thanks,
Bill

Submitted by y2kgolf@hotmail.com on Thu, 07/24/2008 - 11:32

David & Michel,

Thank you very much for your insight and recommendations. I will try all of them and hopefully track down the problem. Would hate to have to get a new condenser.

To answer David's question if I ever found water on the passenger floor: No! Just random spots of dried liquid. I know it is not just water. Water would not leave the discolored spots on the floor mat. As a side note: when running the A/C, I do hear off and on 'hissing'. I don't remember it being so obvious before.

Submitted by david@daviddew.com on Thu, 07/24/2008 - 10:46

If you were in my area of the country, I would guess it is the residual salt from the AC condensation after it dries. Just as you described on my red polo shirt!! I don't know of any other liquid that can get to that spot unless there is some leak around the firewall, but still doesn't explain the discoloration necessarily. By the way, you will not get a great amount of water condensation with an AC operating at a suboptimal level. Normally you would see the water draining under the car through the hoses. The hissing is the refrigerant moving through the system. That usually goes away with a fully charged system.

Best,
David

Submitted by y2kgolf@hotmail.com on Thu, 07/24/2008 - 09:22

David & Michel,

Thank you very much for your insight and recommendations. I will try all of them and hopefully track down the problem. Would hate to have to get a new condenser.

To answer David's question if I ever found water on the passenger floor: No! Just random spots of dried liquid. I know it is not just water. Water would not leave the discolored spots on the floor mat. As a side note: when running the A/C, I do hear off and on 'hissing'. I don't remember it being so obvious before.

Submitted by david@daviddew.com on Wed, 07/23/2008 - 14:14

Martin,
I have the same car and the same problem. Indeed a leak is the cause. I would suggest using a can of UV dye in the system to find the leak. In my case, there showed a small leak in the condenser. I have a 30lb can of 134a, so I can recharge fairly quickly, but it will be time to vacuum the system soon and then I should replace the condenser or repair. I am thinking of pushing a JB Weld "plug" of epoxy through the condenser while it has a slight vacuum as an attempt to repair the leak.

For the "white spots" , do you ever find water in the passenger floor after a spirited turn? It is common for the drain hoses to get plugged. Get under the car and there will be two drain hoses underneath where the AC is and clean them out. This should not be related to the AC leak.

I personally would not use any leak stop in this system. The parts are just too expensive to risk.

David
1995 XJS 4.0 Conv
1996 XJ12

Submitted by michel@dinomar… on Wed, 07/23/2008 - 14:07

Martin,

I had a 1994 XJS and both A/C drain had to be cleaned, i was getting water from the condensation inside the car. Try this first for the marks on the carpet. For the leak detection use a sniffer, start the A/C and put the sniffer in front of the dash vents it it start buzing then the leak is under the dash ( the evaporator is expensive tochangeit costed me $ 3 K for my Aston Martin DB7) then put the snifer on the compressor and on all the A/C hoses in the engine bay, every time there is a buz, there is a leak. I would not recommend using these DIY leak fixer, they will damage the entire system, if you read the instructions on the can it is scary .

Regards

Michel

1985 XJ-S coupe
1988 XJ-S conv
1997 XK8 conv
1997 DB7
2009 XF

Submitted by y2kgolf@hotmail.com on Wed, 07/23/2008 - 13:29

I have a related question. I am slowly losing cold air when running the A/C. It takes about 2-3 months for the cool air to completely turn into 'warm' air. I obviously have a leak somewhere. Now; at the same time I am noticing some spots on my floor mats right below the dashboard air vents. It seems like something is leaking through the air vents and causing these 'white' spots. They almost look like sweat stains on shirts with a white ring around the outside. Is this related to my A/C problem or something else?
If I do have a leak, would you recommend to get one of those A/C leak fluids which fix the leak from the inside?

Martin
1995 XJS Convertible
6 cylinder

Submitted by dougdwyer1@com… on Wed, 07/16/2008 - 08:32

I'm afraid that's how the system was designed, although you should feel a a little blending----a small amount of warm air coming out of the outer dashboard vents when heating is called for and a small amount of cool air from the footwell vents when cooling is called for. I'll emphasize *small amount* here :-). The center dash vent will open only when cooling is called for.

Cheers
DD