Technical Heater/Rear demister/Recirc buttons PCB

[Deedpopo]

Hello from a Punto Newbie. (Ex Panda, Tempra & Marea)


We now have a 1.2 Grande and have already used this helpful forum with the drivers door lock and heater light fixes, however one problem still exists.

The rear demister button seemed to be jammed in, on inspection the PCB inside is totally burnt around the button area.

Now I know I can get a whole unit from ebay for 20 quid but as I have buttons, LEDs and even time delay relays I thought I could knock something up.

To do so I would need to know the pinouts of the blue connector in the picture, can anyone point me in the right direction for this?

Also, any info on this small PCB would be appreciated, going by the amount of components there is obviously more to it, I'm hoping it's just a latching circuit for the recirc and a timer circuit for the demister but if it is CAN stuff then I might as well just get a replacement unit!

Thanks,
Gordon.

 

[Bernievarian]

Hi Gordon,

are we talking about auto or manual climate control ? Here's one drawing about the rear windshield and mirror defrosting. The burnt part of your board is about a power mosfet or a voltage regulator...

BRs, Bernie

If someone here helped You fix -or better, understand- your issue, hit the thanks icon @ bottom right corner, it's free and makes us feel helpy ;-)

 

[Deedpopo]

Thanks Bernie,

This is a no climate control model, there is no center A/C switch and the switch and LED positions on the PCB are just solder pads.

I don't know if the mirrors are heated as well, I shall need to check, this is a pretty basic interior. I'm sure there should be no high ampage circuits around this PCB and that it simply controls a relay so I'm not sure what has caused this fault to cause such damage, I have a sort of dread that there has been some wiring buffoonery which has passed the full demister load onto the PCB so even if I bought a replacement unit it may still burn it out unless I can trace what some numpty has done!

Cheers,
Gordon.