Technical Heater resistor with a difference?! Where do I find one like this!

[declanshood]

Hi all

Got a 1.4 16v sporting mk2b

Climate control system with digital display, fans stopped working diagnosed the resistor at fault, a common problem I read, question is where do I find a resistor like this one?! I'm completely lost! I can find thousands of the other types on eBay but none like the one if removed.

Any help will be great thank you.

 

[PuntoHowTo]

It's not a resistor its a pwm (pulse width modulator)

The climate control system is part of the onboard diagnostics which means you can plug in to identify faults as these systems rarely go wrong I'd be interested to know how you identified that part as being at fault ?

 

[declanshood]

Tested for power at the source and there's power, then tested the motor on a battery and it's fine. Thanks for the reply! Any suggestions what else it could be? Or would you agree it's probably this at fault? Cheers.

 

[PuntoHowTo]

These don't work like a conventional resistor, the controls on the dash send a digital signal to the PWM which pulses the incoming power out to the motor to control the fan speed if the right signals are not comming from the controls it won't work and at £100 for a new pwm you will need to be 100% sure the pwm is at fault because it's a big expense to find it still doesn't work afterwards.

Personally I'd get it put on diagnostics to check and clear any fault codes

 

[declanshood]

I have a AUTEL mot pro I'll do a full diagnostic scan and see if it brings anything up, thanks for your help I'll post up what I find

 

[Monkeh16]

That is indeed a switch mode supply, not a resistor.

Are those four separate pins at the bottom? Anybody have the wiring diagram for these?

 

[declanshood]

Wiring diagram would be very handy, If it is this part I wonder if there's any way of repairing it

 

[Monkeh16]

Wiring diagram would be very handy, If it is this part I wonder if there's any way of repairing it

Only if you're experienced in switch mode power supplies and surface mount rework.. (that's a no)

 

[declanshood]

So this is the reading I'm getting.

Any help with what this means would be great.

 

[Dragon Man]

first of.. i found a place that sells these for about £12.30. its from Poland so get your translator fired up!

http://archiwum.allegro.pl/oferta/opornica-rezystor-fiat-punto-ii-405e0122248-i3380562577.html

now for the tech talk..

hey guys, looking at the picture you have 6 connectors.
2 will be the input + and -
2 will be the output to the fan + and - (pulsed)
and the other 2 will be the control wires.
if some one could find out how these modules are controlled (Resistance, voltage or pulse) i may be able to build these for folk who need them...

i have a PWM here that is controlled by a potentiometer. if i could mod that to work from the climate control computer then it would be a much more heavy duty replacement.

 

[PuntoHowTo]

first of.. i found a place that sells these for about £12.30. its from Poland so get your translator fired up!

http://archiwum.allegro.pl/oferta/opornica-rezystor-fiat-punto-ii-405e0122248-i3380562577.html

now for the tech talk..

hey guys, looking at the picture you have 6 connectors.
2 will be the input + and -
2 will be the output to the fan + and - (pulsed)
and the other 2 will be the control wires.
if some one could find out how these modules are controlled (Resistance, voltage or pulse) i may be able to build these for folk who need them...

i have a PWM here that is controlled by a potentiometer. if i could mod that to work from the climate control computer then it would be a much more heavy duty replacement.

The main issue in your business plan here is that you pointed out where people could buy the component relatively cheaply.

The other issues are that these packs are fitted to so few cars it's literally only a few hundred in the whole of the UK so the number of owners here are going to be maybe ten or so ?

Also they really very rarely go wrong that is the nature of the beast with PWM efficient and reliable.


The final thing is the pin outs, you will have power in and power out via the two larger pins, the 4 other pins are likely power to the unit and ground and then tx and rx serial communication, the fan it's self will be grounded separately from the pwm