ok , so my xjr is overheating....I bought a thermostat but im pretty sure that's not the issue. ( I have yet to replace it )

I noticed my fans do not work.

I checked the fuses in engine compartment and fuse #14 was burnt. When replaced with a new fuse the larger fan ( top of radiator) will work when engine gets too warm but not the smaller bottom one.

After a while though the fuse does burn and overheat occurs again. I switched out the relay and same result.

When rolling at highway speeds it doesn't overheat but it does when stuck in slow traffic.

Any thoughts insight ?

 

Your lower fan should be your intercooler radiator and that is a must to have so you don't score your SC.
As for the fuse burning, it sounds like either your fan motor brushes are burned and are overheating or your connector has a short. Thus it back feeds your system and pop goes the fuse. I'm betting its the motors....
I would remove the connectors and check them for corrosion and/or cracked/broken wires on both ends of the wiring. If you know how to meter wiring, then do that also.

 

Am I missing something (motorcarman?), but I am pretty sure the fans run together on this car, like the X-300. Low speed is fans in series, and high is fans in parallel. So, if one fan runs and th eother does not, it usually means the non running one has a jammed motor in some way.

 

Come to think of it, that is what JTIS and the electrical diagram say.

If the bottom fan is not running, it could be stalling and thus blowing the fuse due to high current draw.

 

Solved the issue guys ...

my circuit 14 fuse kept burning causing the overheat issue.

one day I changed the fuse while the engine was hot and just barely put it in the fuse slot without pushing it in all the way...and voila !! both fans started working.

I deducted that maybe by pushing the fuse in all the way the fuse itself or the fuse slot was causing the short so I left it that way and its been working fine ever since...fans working as they should !

 

Thanks for the update and fix, maybe file or nippex the prongs on the fuse so it doesn't bottom out and short?

 

might be an idea Sean, but for now if it aint broke I aint fixing it :-)

The fuse is only a few millimeters higher that the other ones yet its still safely in place so im gonna wait and see how long this " temporary " fix lasts...hopefully forever :-)