G'day all

Took my 1989 XJS for a long drive today and a fan on the left side under the dash runs all the time even when all the switches and the ignition are off.
Can anyone help with what is causing this please?

many thanks

Trevor

 

You have a problem with the relay and/or transistor located on the inside the blower moor assembly. In terms of labor/effort, I'm afraid the repair, although fully DIY-able, isn't a pleasant task

This will give you the flavor of the job


http://www.jag-lovers.org/xj-s/book/acblower.htm

Cheers
DD

 

Thanks DD

My heart sank while reading this as I have very little knowledge of electrics and am not looking forward to working under tha dash but thank you very much for pointing out the problem so quickly.
I will post some pictures of what I find when I start the job and hope my friend who is well versed in the "black arts" will get his soldering iron out!

all the best

Trev

 

Each fan has its own control board. Over the years some have simply abandoned the faulty control board and re-wired so both fans operate from the remaining board on the opposite side. I can't recall if any negative results occurred. Some speculate that the single transistor would be over loaded.

Let's hear what others have to say about this shortcut

Cheers
DD

 

Well I spent the afternoon removing the left hand blower motor assembly and now have it on the bench.
The relay is buried inside the motor housing and I had to take this apart to get to it.
The Darlington control board was rivited to the housing and was easy to get off.

I will now see my electronics Guru for help in renewing all the components on this.

What fun!!!!!!!!!!!!!!!!

 

 

Here is a circuit diagram for it. IMO it is most likely to be the transistor that has failed. It can be replaced with an MJ11016, these are readily available from RS Components