Heater Fan Intermitant Fault

Hi all.
I have a 2000 JTD with a rather annoying heater fan problem. It started playing up last Winter. The fan would be working fine, warming the car up nicely in the cold weather when suddenly it would start pulsing. It would go off for a second or so then come back on for a second, off, on, off, on. If I left it like that then it would stop altogether in a few seconds but if I turned it down a couple of notches it would stablize and carry on running. Eventually though it would stop even on low setting and leave me without a fan for a couple of weeks until it decided to kick back in again. This pattern was repeated several times throughout the year (stop for a week or two then run for a couple of months).
It has now been off line for about six weeks and I'm getting cold lol. I've had my hand up behind the dash and wiggled evey wire I can reach to no effect. The weather doesn't seem to matter as it happened in cold, wet and aride conditions and it doesn't follow the pattern of a loose earth. This is really starting to wind me up now so any help will be warmly welcomed hehe.
Thanks

hiya have you got climate control

Got air con. Not sure what the difference is, if any. I've removed the filter (the one near the passenger windscreen wiper) completely to see if it helped but no dice.

on the fan speed switch have you got auto.mine played up this year and the wires that come out of the fan had melted

from memory theres a control box in lower part of centre tunnel that plays up.

Yeah, it has an auto setting. If I get access to the back of the speed switch will I be able to cross connect a couple of wires and see if the fan will run or isn't is as simple as that?

Can you let me know more exactly where T and how to get access to it please? TY

the control box is under the dash conected to the back of the fan,i had to cut out the melted bit and connect new connector blocks not pretty but works

Is this the bit you were talking about?

This turned out to be the problem.
Pic1 is it removed (looks like a temp sensor to me).

Pic2 is looking up at it fitted. That piece of grey plastic in the bottom right of the photo is the front of the center console on the passenger side (you're looking up above where the passengers feet go). The bit with the white sticker on it at the top is the fan and the black plastic piece in the center with the two wires going in is covering the electrical plug for the offending article.

Pic3 is the same shot only closer.

Pic4 shows what was causing the problem. The plug into this socket was a melted mess and crumbled away as I tried to pull it out. I ended up with two female spade connectors bereft of their plug casing. I just insulated them with green line tape and pushed them onto their respective spades individually (be careful though, if the wires touch you will get a spark and the fan starts running even if your car keys are in the house so it's prime fuse popping time)

The last photo is just the removed unit from the bottom.

So there you have it, I'm toasty warm again now lol.

I hope this helps a few people out as it seems to happen often if these forums are anything to go by. Thank's to all who helped too.

nice to hear your warm again.mine went in the summer and didnt have air con ,i live in spain and at 40 degrees you need air con!