Anyone have any experience with a 94 ac system? I get only cold air from the registers. The hot water is going thru the coil so that's not it. Its the only part of this car that scares me.

 

Is it cold face level and footwell? Do the demister flaps open when you select defrost, and does the air still blow cold to the screen then?

 

I have that same problem and yes when I put it on deforst its still cold please help....

 

Hi Stef,

Sounds like you're out in the cold. What year and model is your Jaguar? My impression was that you have an S Type, so I may only be able to give you very general advice. This post is about XJS, which is a different animal I know alot more about.

BRUTAL and Real_Tech are the resident S Type honchos, there are others. You're likely going to need a mechanic to look at the car though, there is help to be had here but the magic is on backorder. I'll help if I can.

 

I have an 04 jag s-typeand there is no heat I don't know what to do????

 

Basics only, you have to check your coolant level with the engine cold to make sure the system is full. If it is not, and you have to add alot of antifreeze, that means you have a bigleak and are taking a big chance driving the car.

When you know the engine is full of coolant, drive it around for 15 minutes and turn it off. Carefully touch all the big fat rubber hoses for the coolant, they should all feel very warm and very close to the same temperature. Ifyou feel a cold one, that probably means your cooling system thermostat is bad.

You need to have a mechanic look at your car. You will have better luck asking people here for a mechanic in your area than you will havetrying to learn how to fix the car yourself. That's not meant as disrespect, I couldn't do your job after reading a five minute internet lesson either.

The heater core is inside your car. Think of it like an old steam radiator in an old house: hot coolant flows through it, and a fan behind it blows hot air in your car. So there is probably nothing wrong with your heater core, it just doesn't have enough coolant to flow through it or the coolant is not getting hot... because of a bad cooling system thermostat. The heater core could be clogged, but that is not common and wouldn't cause you to go from good heat to no heat in a short period of time.

 

thanks for the help, your friend stef

 

It started with warm air out of the upper registers and cold air from the bottom. NOw its all cold. There is no longer vacuum to the heater valve but the vac from the engine is good.
I used to be a mechanic and I assembled most of this car. Without diagrams of the heat AC aggregate, its going to be hard to figure out the problem

 

Vacuum closes the water valve for A/C, so that means the system has not fully cycled to cold. 12 cyl or 6 cyl? Heat at screen with defrost selected? Are you sure about hot inlet and outlet heater hoses at the heater core pipes?

 

I have an aberration. My Jag is a 1994 with a 1997 Camaro drivetrain. Six speed manual.
That I know of the a/c unit and the heating coil are good the inlet and outlet pipes are hot.
One of the dampers must no be working. Without a diagram, pretty hard to figure out.

 

Sounds like you are right. If the heater inlet and outlet hoses are hot, the problem is inside the car. If you have no heat when the defrost flaps open, the system sounds like it is not cycling to heat mode. Is the center outlet on the dash open and blowing cold?

 

Its cold out of the center no heat in any direction. Previously, it was just warm out of the center register. What does the temp control on the left actually do> Is it a rheostat?

 

Is the center outlet on the dashboard open?

 

Sounds like a blend door motor is seized or hanging up. I'd recommend a dealer for that one.

 

Well, that advice isn't going to get him too far. There aren't blend doors, there is an upper and lower rotary heating/ coolong flap. And both the servo motors didn't fail.

I don't know where you live, but there aren't many Dealers who service (or know much about) a '94 XJS anymore. And even if they still offer service for a model of that vintage, they might not want to touch the car when they found out it has a Camaro drivetrain installed.

 

I think there might be some glop in the heater core. Im going to pull the hoses. I have had this car apart. There isnt to much I havent been able to figure out. I'll get to the bottom of it somehow.

 

Well, if the hoses aren't hot like you said then I won't waste any more time worrying about it.

 

Good point. I know our shop has many techs that are familiar with Series III and newer - and a couple that actually know their way around the earlier cars. I should have read the entire thread, but I was bored last night and stumbled across this forum - thought I'd throw out a few ideas...