Auxiliary cooling fan on 3.6

[poprivet]

I need a replacement auxiliary fan motor but the OE is rare, expensive and IMO a poor design.

I'm thinking of getting either a Spal, Pacet or Kenlowe of about 9" dia. Space is limited and I would have to fabricate a bracket so I was wondering if anyone else had already done this and could give advice. The 3.6 is different to the V12 for some unknown reason, again perhaps someone could explain.

Mine was working when I tested it last, maybe a year or so ago. When I had it all out recently I wanted to de-rust and clean it. Of course the two long bolts holding it together sheared and there was a lot of corrosion inside, It all cleaned up and went back-together although with a bit of a struggle. Bench testing the motor seemed to show it was working. There was a long wait until I got around to re-fitting it to the car by which time I found it wouldn't fit as it was obstructed by the ac condenser and tie brace, so I spent the best part of a day fitting it back in.

I went to test it but the 10A fuse blew. I checked everything with a multimeter and all seemed ok so I uprated the fuse to 15A and tried again. This time it ran, but not very fast and backwards. I reversed the polarity at the motor connection and although it now goes in the correct direction its still not fast and is drawing a lot of current.

So there we are, not worth spending any more time on. On a 3.6, it doesn't run with the AC compressor only when the rad temp sensor cuts in so it has a very quiet life. Being right out in front it catches all the rain and salt so its not surprising they don't last.

I could just leave it off but I have known it cut in when stuck in traffic after a longish run so common sense says it really is needed.

http://www.jec-xjs-forum.org.uk/xjsbb2/ ... 4-8_tn.jpg

[Telsmoneypit]

Hi Pop,

Fan running slow and drawing a lot of current? I'll bet it's semi seized bearings. We get this a lot at work with the condenser fans on our -80 freezers (they run flat out 24/7/365..)

Don't bother with WD40. It's only an interim fix. You'll have to pull the thing out again and see if there is a spec label on the actual motor. Once you have the specs you should be able to easily source a generic motor from someone other than Jaguar via the net. It will be much cheaper as well.

I would advise that you replace the 10A fuse pronto. The fuse is there to protect the wiring from straining motors. By upgrading to a 15A, you could be looking at a possible 'Lamborghini' type inferno.....

Best regards

Tel

[poprivet]

This reply got 'lost' in the forum transfer, but I thought it might be of use to other 3.6 owners, so I've copied it here. There are major differences between the 3.6 and V12 in the aux fan design by the way.

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Finally getting around to solve this problem. I've found a Spal fan which will do the job,

click here for details

I would have liked to use the original cowl mount but its corroded and space is tight in there. A 9" fan may have been a better choice, but with less airflow. Without the original mount, it was secured to the A/C condenser matrix with those plastic tie fixings, not the best engineering solution but the easiest.

It draws about 6 Amps when running, which is well within the electrical spec of the original.

Compare it with the original fan.





Maybe it won't satisfy the purists in that it isn't original, but my car is (or will be at some point) used for everyday use and is definitely not a show car, so reliability is more important to me then originality.

I have provided a way of overcoming a particular problem and I hope it will help others to find a solution. I would add that there are many fans available, many such as can be found on a well known internet auction site, are of poor build quality so I would recommend you stay with the well known brands such as Kenlowe, Pacet or Spal.

It is generally regarded that straight blades move more air, but are more restrictive when not powered. Curved blades 'windmill' when not powered and are less restrictive. Some of the cheap fans say you can reverse the polarity to change the fan from a pusher to a puller and vice-versa but the better makes have aerodynamic shaped blades that are optimised for one way flow only.

[steveww]

Beware of those plastic through the radiator fins type of mount. With the vibration of the fan etc they eventually rub away at the tubes in the radiator and cause it to leak. I have had this happen a couple of times and the radiator repair shop who fixed it for me says they see this all the time. Fabricating a proper bracket is the only solution.