89 xj-s cooling system
 

A few months ago I bought an 89 xj-s. Since the car had a few owners before me, i don't know what is still original and what are mods on the car!

I've read a lot about the importance of keeping the cooling system in top shape! Can anyone tell me how many ventilator fans were standard on the radiator? I see a yellow fan driven by a belt and next to that a black electric fan... Is that original or not?

Best regards,

frederik

Frederik,

The yellow fan is indeed original, and I am surprised it is still intact. The replacement were white and/or black. The yellow had a bad habit of exploding.

The small electric fan (4 blade originally) is also original. Some markets had that fan wired as an "overheat" relief fan, and some had it as "on with a/c". Either way they were notoriously unreliable, as was the circuitry controlling it.

Most of them down here run a Ford twin thermo fan unit from the Aussie Falcon series, of about 1996 onward. That does away with the mechanical fan, and 1 fan belt and its adjuster, and I wire them as RH fan is thermo controlled, and the LH is a/c only.

TOTAL cooling system cleanliness in mandatory prior to thermo fan installation in MY opinion.

It is also mandatory if left as designed, coz an overheated V12 is going to be very sad and lots of $$ will leave the bank account.

Ohh.. I have a yellow fan in mine...

Guess another thing on the "to replace" list.

Q: Turning the key to start the key, first position, the small fan seems to start, then when the engine runs, the main fan starts.. Is this fan not thermo controlled to start when Temp gets to a certain point?



1986 XJS 3.6
61000miles

Yes, might be a good idea. Take a hard look at the blades and you'll almost certainly see age cracks.

The danger is double if the fan clutch seizes up, allowing the elderly fan to spin at full engine RPM





Pre-89 models (I'm talking V12s but probably the same on the 6 cylinder cars) were designed so that the the e-fan operates:

A)whenever the coolant reaches X-temperature (94ºC as I recall, via a temp switch)

OR

B)whenever the a/c compressor was engaged (via voltage from the compressor clutch circuit). And, since the a/c compressor is engaged in all climate control modes, that means the e-fan comes on all the time!

Turn your climate control "off" and try again.

Later cars had several different e-fan wiring/operational schemes.

Cheers
DD

Thx for the interesting replies, i will check on the blades asap. Are there any useful mods with european model parts instead of australian ford falcon parts! Unfortunately we don't have these cars here. Where should I start, parts, wiring,...

I removed mine and replaced it with an aftermarket electric fan that is temp controlled.

OK, not real clear where you are, so I would suggest some measurements of the radiator. The Falcon fan specs are 740mm X 480mm X 90mm, and slid straight in, almost. Some lugs needed cutting off the plastic, but that took 20 seconds.

Go to your local scrap yard/wreckers/breakers/whatever you call them, armed with the sizes and a tape measure and look around. You will need "sucker" fans, as in mounted on the engine side of the radiator, unless some serious mods are done to fit "blower" fans.

Most European cars have "blower" fans, Australian, American etc have "sucker", USUALLY.

My wiring was simple, like me, RH fan was thermo, using a relay and the FACTORY switch already in the lower hose inlet to switch the earth circuit.

The LH was again relay controlled with the power wire of the a/c compressor doing that relay activation. I had a compressor by-pass switch on mine so the system could be used without that compressor running ALL the time.