More Heater blower problems

[peter306]

Morning Jim,
I've got the Aircon diagram, the Blower regulator i've seen but is beyond me, if I was still working that would have been no problem as I worked with people who's job was repairing aircraft electronics.
I'm still waiting to hear from Chris about the aircon ECU but i'll ask for an update. There are a few on ebay but they have a different number, as mines the base model I don't know if that would affect anything.
As for the Blower regulator the ones on ebay show a different number or no number, on your previous post you specified MJ11015, will any 30amp PNP transistor do as I can check the ones with a number showing.

Peter

[peter306]

Forgot to say Jim,
I'm in Royal Wootton Bassett just south west of swindon.

Peter

[CitroJim]

I saw Chris at Junior parkrun this morning. Had I known I'd have asked him

As for the Blower regulator the ones on ebay show a different number or no number, on your previous post you specified MJ11015, will any 30amp PNP transistor do as I can check the ones with a number showing.

No, only those with the MJ11015 darlington transistors will work. I've seen knock-offs with MJ11016 darlingtons. These are the complementary NPN ones and cannot work in the circuit without significant modification.

A fun fact or two: the MJ11015/6 devices were originally created for high-power audio amplifiers. Citroen used them for a role they were never designed for and cheaped out twice by using PNP ones to avoid the use of a mica washers to insulate them from the heatsink and failing to incorporate low-value emitter resistors into the design to improve current sharing between the pair. When replacing them, it's essential to use a pair from the same production batch so they stand a fair chance of current sharing reasonably well else they will very soon fail.

All the additional circuitry does in the regulator is to operate the full-speed relay! Very complex for what it does!

I do occasionally pass fairly close to RWB when on my way to and from Somerset. I'll advise next time I make the trip - always mid-week but at very short notice - and maybe we can put two heads together on this...

[peter306]

Looks like I'll have to order a regulator and 2 mj11015 transistors then and do a bit of soldering.
As I asked before will any xantia/xsara air-conditioning ecu do as I would assume if it has everything the car will only use what it's equipped to use.
I assume that's to visit Alasdair for holidays.

Peter

[CitroJim]

I assume that's to visit Alasdair for holidays.

Yes indeed, visits to Alasdair unless on my way to the seaside

[peter306]

It's now running as it should, I reread all the posts and picked up a couple of things which I then checked, aircon connectors cleaned, checked the light on the switch, that was a bit dim and the final check was the fuse box, changed it for a spare i have had for some time and it started working. bad fuse box.
Thanks everyone, especially Jim for all the info he gave me.

Peter

[CitroJim]

It's now running as it should, I reread all the posts and picked up a couple of things which I then checked, aircon connectors cleaned, checked the light on the switch, that was a bit dim and the final check was the fuse box, changed it for a spare i have had for some time and it started working. bad fuse box.
Thanks everyone, especially Jim for all the info he gave me.

Peter

Wow! That's absolutely great news Peter Well done!

[peter306]

Yes it is Jim and mainly down to you saying you had never known an ECU to fail. I looked for indirect causes and the fuse box was a one liner in someones elses post.
Just hope it lasts now.

Peter