Technical Punto Mk1 Electric window conversion (identifying relay E2)

[alagregg]

Hi,

I am trying to convert my mk1 1997 Punto to have front electric windows.

My car does not have the aux fuse box, (optional devices control unit) so will be looking to get the necessary parts/wiring from a scrap yard.

I've looked at the wiring diagrams in the Haynes Manual, and the Fiat guide, and it looks relatively straight forward.

However, in the scrap yard, none of the electric windowed MK1 Puntos had anything that even resembled Relay E2 (the Electric Window Control Unit), as described in the Fiat guide. In fact the Aux fuse box (behind the glove box), didn’t match the diagrams in the Fiat guide

So I am assuming there is different wiring in certain MK1 Puntos.

- Does anyone have a part number for Relay E2 ?,
- Can anyone confirm if there are different types of Aux Fuse box for the MK1 Puntos ?

- failing me finding a Punto that matches the wiring diagrams I have, does anyone have an alternative wiring diagram for the electric windows ?

Thanks in advance,

- Al

 

[PuntoHowTo]

an easy way of doing this used to be swapping floor and door looms from a similar aged car.

without seeing the diagram I cant comment on what the relay actually does, but I suspect its nothing more than switching on the electric windows circuit with the ignition, I'm sure in this case a you could substitute a generic high current rely off the shelf in most motor factors
on later mk2s i know that the BSI controls this switching as it keeps the window circuit live for a number of seconds after you have switched off so if you forget to close the windows when you stop the car you can wind them back up without the need to put the key back in the ignition,

 

[alagregg]

Thanks the reply.

Amongst other things I think the relay switches off power when the window reaches the top or something is jammed in the way (I'm not sure if I actually need this).

Looking at the circuit diagram, I'm not even sure the 'electric window control unit' even works as a relay as there is only one live feed to the motor and that goes through the switch (at least for the passenger switch). I wonder if I could just ignore the control unit, and power 12volts up through a 30Amp fuse.

I'd hoped it would be a straight forward job, as I didn't really want to start pulling the dashboard apart. I could hook up the few wires needed for the windows myself. (As I don't want any other features). However that suddenly becomes harder if the circuit diagrams are all wrong, and even the electric window relay/ control unit don't match.

That said, I would be great if I could find what 'electric window control unit' E2's part number is. or work out what model/year of punto I should be looking for.

 

[s and b]

if you think about it the motor on the window only goes up and down depending which way the current runs
so if you get a two way toggle switch that normally powers electric windows you would see that tuned one way the power goes up one side of the motor and toggled the other way the power would go up the other side to the motor

easiest way to confirm this would be by putting power to a suitable switch from the junk yard and using a digital multimeter confirm power + then power minus - by toggling the switch

also make sure the switch can handle the power of course so it doesnt burn out

 

[PuntoHowTo]

electric windows are pretty simple motor cross over switch and some sort of power supply that is pretty much all there is too it, gets more complicated when controlling one window with two switches as with many cars that have drivers door mounted controls separate to the passenger or rear window controls but that is about it if you have the motors the switches and a fuse then its a pretty simple job to get them working as electric windows, i would still advice you consider fitting the door wiring looms as this gives you the ability to connect the wires between the doors and the car body with the correct fittings so it doesn't look like a bodge.
As i said the relay is most likely for switching power and not for window bounce back, stick your hand/head in most electric windows and it will try to remove said body parts