Yup. went through all this on my Land Rover... Those Brits do some wacky stuff with wiring. heater motor draws 50 amps!! and uses a sinking circuit system.

 

This might help, if yours was early production there will be a diode near the fan connector in the harness. Red and yellow hi lights from previous posts.

 

A simple test, take the cooling fan relay and place it in the horn relays place, does the horn honk? Does it beep when you press the lock button on the fob twice? There you go , it’s a known good relay place it back in its place .

 

probably not the time to work on this. still snowing outside

 

Tanning weather up here!

 

Got about 5 inches before I left for work.Hopefully the snowblower starts in the morning.. gotta get the beach cleared for those sunbathers!!

 

My trusty 1978 MTD 24 inch 2 stage at the ready! It wards off snow, I really only need it when it’s not ready!

 

I kept the snow away for almost 10 years by buying a snow blower.
To answer the speculation of how the fan starts when the AC compressor is running; The BCM knows when it turns the compressor on (by energizing the relay) So it tells the ECM to turn the cooling fan on (by energizing the relay). In both cases by sending a ground signal.
What I am getting at is: if the fan doesn't run with the AC the overwhelming candidate is a bad fan. It may have blown the fuse when it failed.

 

the fan is the weak component, but it is much easier to replace a fuse or a relay than to take apart the front to get to the fan. Today I drove the Land Rover as 4wd is nice to have in the snow and frozen roads. The extra weight is nice too when the winds get strong, like tonight when I drive home after midnight. predicting 15-30 mph winds..

My snowblower is an old Sears trac-drive unit with 38" cut and a 13 hp motor. It rarely gets stuck or breaks traction. Does take 2 men and a small boy to make corners and turn around. Same thing. as long as it is working, it doesn't snow. Except for today..

 

started doing this again on the way to work... temp was 5 above and the temp climbed up to 201 while driving at 65 mph... I pulled over and it went down to 196, then I turned around and drove back home (15 miles) and it got up to 199 twice. Works fine wen the temp gets higher, I did add a gallon of anti freeze (straight ) to make sure it had a good mix. Guess I will go with a thermostat and use a 180 thermostat. Pretty sure there is a 195 in there now. Hope it stays warm inside when the outside temp is -25 below zero.