Jaguar XJ-Series Heating/Cooling Issues

jumangiajumangia Member Posts: 5
edited April 2014 in Jaguar
Hello everyone. I have been reading the boards to find out if someone has had any issues with Heat not working in XJ8. I own a 2001 XJ8 Vandenplas and the heat stopped working. I started to check items that I know would more then likely cause the issue. I checked the hoses coming in to the Heater core and the exit hose. I had heat one the incoming but not on the out going. I figured the Heater valve to be bad so I replaced it. Still the same issue(even though I tested the valve before installing it). I have the CD that came with the car (No Maintenance book) that says there is also a Motor ? that sends the water through the heater core. I have tested the voltage that comes from the climate conrtrol system to make sure it was sending the correct voltage for the valve to open and close. I guess the question would be: Could the Motor for the heater be blocking the path? The AC works perfect. Has new water pump and thermostat. The Temp sets in the middle range of the gauge. Temp sensor is new as it came with the plastic piping. (Hoping its not the climate controll inside the car)


  • jade4jade4 Member Posts: 4
    i have the same problem, can you tell me were the heater valve is ? i can't seem to find it . thanks for any help.
  • jumangiajumangia Member Posts: 5
    yes, rear of hood compartment. Left side right under the filler(where you add the antifreeze). You have to remove the plastic covers to get access to the Heater Valve.
    Oh I replaced that heater valve and that didn't fix the heating problem. I dug further to find the Auxillary Heater motor was not spinning, it is located just in front of the Heater Valve. I am crossing my fingers that the one I ordered will fix the problem. Will let you know if it does.
  • jumangiajumangia Member Posts: 5
    Well that didn't fix the Heat either. Seems there is something else that is causing it to not function. After taking both items out and bench testing them, and of course they both work. The auxillary pump relay is only getting +12volts when the pump is connected. With it disconnected there is no Voltage to the relay. Which is wierd in my book. from my understanding the relay should have 12 volts constant on one terminal. If there is anyone out there that has some insite on this one please feel free to post what else needs to be tested or replaced.
  • jade4jade4 Member Posts: 4
    check fuse behind right heel plate
  • jumangiajumangia Member Posts: 5
    Ok, after checking the signals sent from the Controller to the Climate control (computer) tested good. Ohm's checked the Wiring from the Aux Motor and Heater Controll valve. Those tested good. The ground signal from the CCM to the relay was not coming out. Bad CCM. Replaced the CCM (Used of course). Motor and Heat valve are working. Shotgun is loaded for the rest of the story=). I am only getting some heat out of the Left front Vent only. Not getting any heat out of any other vents. Very mild heat. So there is still something not working right. Gonna be a cold weekend trying to find the Problem. Either I have a door not closing all the way or the Water is still not flowing fully through the core. I will check the Fuse behind the Right Heel Panel though just to make sure..
  • jade4jade4 Member Posts: 4
    pump is not working strong enough i had same thing in stall 15 dollar rv pump heat is great will change when back to right pump when find used ome
  • jumangiajumangia Member Posts: 5
    Heat Fixed!! Ok after replacing the CCM electrical power was restored to the Heat pump motor. But only had heat at left Vent. I figured there was something blocking the coolant. I removed the hose from the motor going into the heater core. I blew air through the hose. At first the air wouldn't blow through it. Finally it did. This is a main problem. make sure that when you get your car serviced anywhere that they do not mix the Anti freeze. It will make a Jel and block the core. I know there are places that sell the Green antifreeze that is supposedly compatible. Don't do it it won't mix. I hope all the stuff I have done will help others with their heat problems. Jade4 I did find a used Pump on the internet for $138.00 Dollars. My old pump still works but the contacts in the motor are worn down along with the contact on the windings. I will see if a local electric motor repair shop can rebuild it. Will let you all know if this is something that can be done to reduce the cost of buying used or new ones. Anyway <<<<< Happy in Tennessee now!!!! :)
  • OME_OMYOME_OMY Member Posts: 12
    Tried freon only with local general shops, slow leak. but looks like i am headed for major air conditioning work in the spring. Anyone out here have the problem of the air conditioning working, but not ever cooling very well. Max button doesn't do anything. This A/C has been weak since buying it several years ago. Freon loss isn't the problem. I hate the prospect of new compressor, dryer, etc. :confuse:

    And what drives me crazy, is that when i turn the switch on, the A/C comes on when it wants to, about half the time. And when it is hot here in Louisiana, we NEED A/C. Seems like an intermittent switch. Here we go again with electrical problems. :(
  • OME_OMYOME_OMY Member Posts: 12
    :shades: My search is focused on looking for a good or great Jaguar mechanic/tech. Particularly electrical/computer problems and enhancements. My experience with the Mobile Alabama Jaguar dealership and others is that...The techs that are great for newer models are not old enough to be great with my era Jaguars...1994 XJ6

    I will travel long distance to any southern states particularly to find such a tech and service facility. Texas, Louisiana, Mississippi, Alabama, Florida, Tennessee, Missouri, Arkansas for example. Do YOU know one? :surprise:
  • RonmayRonmay Member Posts: 2
    My heater pump failed a few months ago. I tried finding a used pump, but they wanted $300 for a used one. I finally tore down the pump and rebuilt it myself. If the armature isn't too chewed up, just dress it down woth sandpaper. If it's too bad, have it turned at a shop. I found new brushes(slightly oversize) at Stine lumber for $6. I had to cut them down slightly with a file, but that was easy on graphite brushes. Make sure none of the segments on the armature commutator are shorted. run a thin piece of metal down each groove to remove any trash. Total cost of the job: $6.54.
  • joeyxjrjoeyxjr Member Posts: 4
    Belive it or not it is likely the fan motor (blower motor)in the car.If it is going bad the blower motor will stick on air or heat ...........wich ever u used last.
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