I noticed the other day when my compressor kicks in my upper rad fan runs "higher" for lack of a better turn. I've never noticed this before and don't think its something I wouldn't have noticed before. Is this normal operation? Maybe it just wasn't working right before. It seems quite "loud" when it happens which is what made me notice it. I stood with my hand behind it and it was running like normal then the compressor kicks in it gets louder and pushes harder on my hand, when the compressor kicks off it runs back to normal like the lower one.

 

Not sure what work around your market got with that a/c tranary switch..

Mine had the fans (both) on LO whenever the ign was ON, and I found somewhere (and for the life of me I cannot find it now) how to bridge, with a relay, the fans back to thermo operation, but still have them ALWAYS on when the a/c was on. Still a bit of a wast, but better than teh factory set up.

This I did, and I was quite pleased with the results.

Both my fans never ran at HI speed, although I assume they would if the situation called for it.

The usual reason for what you are describing is a bad earth, and a feedback is creating the increase when the comp cuts in, but exactly where is a mystery to me also. Why 1 fan over the other is also odd.

 

I'd like to get to the bottom of it as it's quite loud and fairly undeserving of a Jaguar to be making such noise. It ran fine for three summers in my possession w/o doing it.

 

This is all I found so far.

When I get a minute, haha, I will get the key from the new owner, and go down to the storage facility and look at the Green Machine, and see if I sort what I did for thermo operation.

I am sure I found that thermo rewire tip on here somewhere a long time ago.


X300 fan fuse TSB.pdf

X300 fan TSB.pdf

 

what is the behaviour of the lower fan ?

 

Both fans are kicking on high and this AM with the A/C on and OAT in the 70F range they didn't. As soon as I went out for lunch they did. They will cycle high then low when hot and when the compressor cycles. I guess this is normal operation that I've never noticed before.