Hi everyone,

I have a 2001 Skoda Fabia Mk1 1.9 SDI Classic with A/C. It is a very basic model, currently equipped with manual front windows and manual mirrors.

I'm looking into retrofitting the OEM electric front windows and electric mirrors using parts from a suitable donor Fabia, preferably an early Mk1 with the same generation of Comfort system as my 2001 car.

So far, my plan is to source from a donor:

• front left and right electric window regulators + motors

• the corresponding door control modules (J386/J387, if applicable)

• front door wiring looms

• window switches / switch panels

• electric mirrors

• mirror adjustment switch

• the relevant body-side wiring between the A-pillars and the Comfort module

• the donor's J393 Comfort/Convenience module, if required

I have been studying the wiring diagrams, but I have a few things I would really like to confirm before buying and dismantling a donor.

1. Body-side wiring

This is probably my biggest question.

I understand that the door wiring harness itself is relatively straightforward: the door loom connects through the A-pillar to the vehicle-side wiring.

However, I'm trying to understand what happens on the vehicle side of the A-pillar connector.

Does the wiring from the A-pillar to the J393 form a separate branch of the body/interior harness, or is it integrated into the main dashboard/body wiring harness?

In other words, if I find a suitable donor, can I remove:

J393 → relevant body wiring → left/right A-pillar connectors

without having to remove the entire dashboard wiring harness?

Or are the wires for the electric windows/door modules integrated into a larger common harness with other vehicle systems?

If anyone has pictures of the body-side wiring / A-pillar connectors from a factory electric-window Fabia, that would be extremely helpful.

2. Comfort module

My current understanding is that the early Fabia uses the J393 Comfort module together with the front door control modules.

My current car obviously has a Comfort module already, since it has central locking, but I'm not sure whether the module fitted to a basic Classic is capable of supporting electric windows/mirrors.

Would I need to replace my J393 with the module from the donor?

Or does the existing module already support the necessary functions and only the additional wiring/door modules are missing?

If a replacement J393 is required, are there specific part numbers/revisions I should look for?

3. Electric window system

From the wiring diagrams it looks like the electric window motors are associated with the door control modules, rather than being controlled directly by the J393.

So am I correct in thinking that if I take the complete electric-window hardware from the donor — including the motor/regulator, door control module and door loom — I don't need any additional window controller elsewhere in the car?

4. Electric mirrors

Is the electric mirror adjustment controlled by the relevant door control module, or is there another separate mirror control module?

My assumption at the moment is that I can take the complete electric mirrors, mirror switch and the necessary wiring from the donor and connect them to the appropriate door module/loom.

5. Compatibility / donor year

My car is from 2001, so I understand that there was a change in the Fabia Comfort system around 2004.

I have seen references to the earlier Comfort CAN system and later LIN-based systems.

Therefore, should I specifically look for a pre-08/2004 donor to avoid mixing the two generations?

Would a 2002/2003/early-2004 electric-window Fabia be the safest donor for my 2001 car?

6. Remote central locking

My current key is only a normal mechanical key — I don't have a remote-control key.

If I install a donor J393 that supports remote central locking, would I later be able to have a genuine OEM remote key programmed/adapted to the car?

I'm not particularly interested in the remote key at the moment, but if the correct Comfort module is already being installed, I'd like to retain the possibility of adding it later.

Also, does changing the J393 have any effect on the immobiliser, or are the immobiliser and remote-locking functions separate?

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My current idea

My ideal retrofit would basically be:

Donor:

• J393

• relevant body-side wiring

• both front door looms

• J386/J387

• electric window regulators + motors

• window switches

• electric mirrors

• mirror switch

Then transfer these to my 2001 Classic and connect everything using the factory connectors/wiring.

I'm hoping this can be done mostly OEM / plug-and-play, rather than running completely new wiring from scratch.

If anyone has actually done this retrofit on a Fabia Mk1 that originally had manual windows, I'd really appreciate hearing exactly what you had to change.

Especially interested in:

• exact parts required

• J393 part numbers

• J386/J387 part numbers

• wiring diagrams

• A-pillar/body-side wiring

• donor year/spec

• VCDS coding/adaptation

• anything that turned out to be unexpectedly different between manual and electric-window cars

Thanks in advance! Any information, photos or part numbers would be hugely appreciated.

There's a helpful chap goes by the name of Pete who might know a thing or two about it.

@Breezy_Pete