How's it going..
I'm having trouble with my 96 xj6 it's overheating when I turn the AC on.. the temp hand is normally riding right in the middle .. sometime Rises if I'm sitting at a light for a long period Of time or anywhere else .. Does anybody have any theories or solutions..?

 

Check the engine/climate control heat exchanger fans (RAD FANS).

lots of TSBs for that era fan issues.

I just had a customer that kept loosing the top Rad hose and coolant. She came in and I found both fan fuses melted!!

bob

 

The fans Are working.. I guess my question would be are they high/low fans. As in are they supposed to kick in at a higher speed when the AC is being ran..?

 

The water pump belt may not be turning because of a defective and internally slipping harmonic balancer

The compressor pulley " load " may be triggering this

This involves 2 different engine belts , but they are tied together at the harmonic balencer " drive " pulley

Place 2 white stripes on the balancer and see if they stay together as needed

This staying together can be checked before and after engine run and not necessarily during

https://www.jaguarforums.com/forum/x...lancer-101674/

 

Originally the lower fan kicked in at a lower temperature (86C) and refrigerant pressure (12 Bar) but the later cars are modded so that it is permanently powered.
The 2nd fan comes on with higher temperatures (100C) or refrigerant pressure (20 Bar).
There was a TSB for earlier cars to be modded to behave in this way (attached).

I had faulty wiring to the lower fan which meant it wasn't behaving properly and the AC was over-pressurizing.
But even when the lower fan wasn't working at all the engine temp was always good - UK temperatures mind.
I think you should have more cooling capacity regardless of AC.

 

BOTH fans run in SERIES on the low speed and run in PARALLEL on the high speed.

The fans are NOT independent. They both run at the same speed together. (low or high)

bob

 

Ok thank you. I will definitely look check that today.

 

I remembered it otherwise but motorcarman is absolutely correct, my error.
Apologies for being misleading.

 

Double Post

 

Which switch or sensor is the one that triggers the fans to run on high..?

 

The engine temp and/or the a/c system pressure will determine when the fans 'jump' to high speed.

bob

 

The 2 position 3 wire coolant temp switch on the aft rear lower portion of the radiator will trigger the left only or the both fans operation

The A / C freon has a 2 wire low pressure switch for the left fan only and a 4 wire high pressure to turn on both fans

There was a TSB to keep the left fan on at all times regardless of coolant temp and freon pressure

Not all cars have been moded

The heart of the fan control is the fan control relay module

This is located under the car just fwd of the left front wheel

To test the fans remove the 3 wire coolant temp connector and jumper the white wire to the black wire with a paper clip and you'll get the left fan

Remove the clip and jumper the other white wire to black wire and you will get both

This is a low current portion of the circuit so no arcing danger and key on but engine not running

To test the A / C switches remove and jumper the 2 wire pressure switch and you will get the left fan only

For both fans jumper the 4 wire connector with the White / Blue wire and any of the 2 Black wires , doesn't matter

The Blue / Black wire is the overpressure switch that shuts the A / C off

The fan control relay modules can get water inside ruining them if mounted upside down

You can shake it and hear the water

For troubleshooting you can carefully remove the right fan motor connector and bring it over to the left fan motor

The White X300 module is not interchangeable with the Black module for the later V8 X308

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