I have gotten my hands on a XJR6 from 1995. Very well maintained but it has done 226.000 km. Ca. 140.000 miles. Fully documented service etc.
It has not been driven for some years and I have taken some long drives in order to wake the car. This makes up for some problems.
My problem is - the two cooling fans does not come on at all - not when very hot or even with the a/c turned on.
I noticed the problem when the car was still with the engine running. The gauge was all up in the hot area and some smoke came from the right side down by the shield of the manifold.
The fuses are ok - could it just be that the fans are worn out?
The oil and coolant are ok as well. No blow gaskets etc.
Do the fans spin by hand? Can you power them directly? Could be very low coolant (unlikely) or the fan switch or the relays that turn them on and off. Could also be the ECU if that is involved, or the wiring.
Check that you have the link wire on the single pressure switch.
Also check that the fans are connected. Often, as the fans should be set to run slow ALL the time, people will disconnect them (think bottom of rad) whilst doing work that needs the ignition on otherwise the battery drains very fast.
It could also be the fan control relay. This is under the front bumper, right in line for getting wet and manky.
