I had broken Blower Control Unit and thanks to this and UK forums, I managed to fix it by changing thermal cut off and FET. So now it's blowing. But it's blowing full, no matter what speed settings there is or auto on it just keep blowing a long as Climate Control is on. Turning CC of cuts power from the blower so basically it's on/off. Running SDD shows temporary Blower Motor fault but no on after fixing the blower control unit. No another faults. So next suspect is a Climate Control Unit. There's 1,7 volts in output for blower control when disconnected and 2.7 volts when connected. And that voltage didn't change when adjusting blower speed. That's as far I managed to go. What shall I do next? Getting new Climate Control Unit? Or is there any way to test it.

 

What was the original fault?

Was the blower not blowing?

Only guessing but I think the fault must lie with the control unit.

Did the speed control mimic move when speed control was pressed and does it move now?

 

Dear mjrpayne,

Welcome to the forum! In addition to answering meirion1's questions, please tell us the year and model of your car. Also, as soon as you can, please post an introduction in the New Member's area.

Thanks!

Don

 

Yes, original fault was the blower not blowing. And the speed control mimic moves when adjusting speed manually. Also all vents controls work too. Only fault is that the blower is full speed all time.

 

See my next post

 

Original FET Toshiba 2SK2313 which our regular suppliers only sell in lots of 3000.
Replaced with a device having higher current specs but TO220 industry standard package. Not as much heatsink area as Toshiba. It lasted 20 minutes then short circuited, no big surprise, which means I can have no blower or full blower which is better than previous no blower only.


The above is a quote from https://www.jaguarforums.com/forum/x...ocation-62718/

looks like your FET has blown.

 

First I replaced FET with IRF1010EPBF but noticed that the fan is in full all time. So I thought it's not fully compatible and looked for original type which I found original from this supplier selling them in lots of 10.

10pcs 2SK2313 K2313 N Channel mos Type | eBay

But with the original, same thing. I'm going to investigate it more next week. Maybe test the BCM in a lab where I can control input voltage better.

 

I think that IRF1010EBF is the RC Components FET which I installed in my car in 2009 I think it

was when I lived in the UK.

It's strange that your original symptoms were the same as those for a blown FET.

Hope you are able to work it out and fix it.

Let us know how you get on.

 

I found the fault. It was thermal cut off switch replacement. The one I got from a local store had a metal case instead ceramic as original. And that case was connected to one of leads. And that cause short-circuit to drain via cooling fins causing the FET to be open all time and running the fan in full power. Simple electronic

 

You may have noticed that one of my previous posts said "see my next post".

This was a post that I deleted because I decided that I may have been misleading you, however one of the suggestions in that post was:

May be a short due to the heat conducting paste (which I assume is electrically conducting) causing a short".

It's good to DIY these things because that's how to learn and if the fault happens again (which mine did after 4 years) we are experts!