Hi guys,


I've got a 1999 XJ8L and up till the today the A/C has been operating fantastically. But out of the blue it just started blowing warm to hot air. The belts are fine and the compressor is on the high end of a good charge. Other words I can't add any more coolant without overcharging.


Are there any suggestions of what I should check next? Thanks in advance I would appreciate any advice you may have.


Sterling

 

May I assume that you have checked both the low and high pressure sides with the comment: If not and you are only reading the low side is the compressor clutch engaging? The reason I ask is that the static, non operating pressure can and has been confused with a correct low pressure side.

The next suggestion is to check the blend door which may have stuck open overcoming the cool air with heated air. Run the temp control to the top and bottom 2-3 times to see if that makes a difference. I have had two Ford/Lincoln vehicles with this problem. Very difficult and/or expensive repair so I learned to live with it by the high/low exercise.

 

The only way to check that the system is correctly charged is to evacuate it and measure the amount of refrigerant in the system. As 'testpoint' says, you can get a high static reading even if the system is low on refrigerant.

Are the cooling fans kicking in when the compressor kicks in ? It should. The compressor will kick in even when the system is low on refrigerant, say about 200g, but you will not get any cold air.

First job, evacuate the system and measure the amount of refrigerant, then vacuum and refill.

 

Hi guys,


Thanks for the advice: A quick up date: I evacuated the system and started charging again, I got it to where the gauge read I should be getting cold air, yet the air was slightly cool at best. Then I noticed running beneath my feet the water drip off that accompanies a working air conditioner.


I was puzzled and figured Check Point was right and cycled my climate control from Hi to Low several times to no avail. So I figured I'll get my car to my mechanic my next day off. I drove it for the last three days burning up then I started getting an engine coolant low message. I checked and it was full and the car wasn't hot (half way between H and C at worst). I was able to add about six ounces of anti-freeze. But the light wouldn't go out.


Got in my car this morning planning to go the mechanic and air conditioner blew like I was in Alaska. But the Engine Coolant Low light is still on. Do yall think these things are related. Is there a way to put anti freeze directly in the radiator? The radiator fluid resoiver is far from the radiator and the car doesn't have a radiator cap far say.


Again thanks for the help guys I would appreciate advice you have to give.


Sterling

 

The low coolant warning is triggered by a ring magnet inside the reservoir tank that slides up and down on a shaft. Shine a light down there and see if you can free it, it's probably stuck. The wires are connected underneath, might want to check the plug also. I don't think that could be related to the A/C problem. Don't trust the temperature gauge - many on here have had serious problems before the temp gauge showed anything wrong. Seems to me there is a large allen head plug at the highest point of the cooling system above the thermostat. I take this plug out and pour coolant into the reservoir tank until it is about to overflow (from the plug hole) and then cap everything. Some say to elevate one side of the car (to get all the air out). Another thing to think about - if the green and orange coolants have ever met in the cooling system - it's trouble with clogging.

 

Once you CAREFULLY remove the thermostat housing cap with both a 10mm Allen wrench AND a strap wrench you can add coolant at that high point in the system. Squeeze the upper radiator hose to 'burp' air out of the system.

Many a plastic housing cap has been cracked by using only the Allen wrench.

Another part of the AC system is the thermostatically controlled fan system. That needs to work correctly for the AC system to work.

 

Thanks guys I'm going to try filling it tomorrow.