DIY power windows: Re-engineering the Chapman system

[yellowelan]

The motor + bar successfully inside the door skin:

[yellowelan]

Connected a piece of blue plastic tubing that came with the kit to the other end of the motor with a jubilee clip. This directs the worm drive upwards and protects the worm drive when the window is down.

Here is a picture of it inside the cavity

[yellowelan]

Place window frame inside the door cavity. I just packed a sanding block and a welding glove between the window frame and top of the door skin to give me some space inside so I could thread the worm drive into the motor:

[yellowelan]

I connected the motor to an external battery pack so I could wind up the slack in the worm drive:

[yellowelan]

Next I bolted everything up. As you can see when I was designing the system I drilled all the mounting bolts for the metal flat bars around where the original wiper motor sat so it was easy to do this when it is inside the door cavity.

[yellowelan]

That completes the mechanical side of the install. I hope that answers how you get all the components inside the door skin.

[yellowelan]

The modern bosch motor/worm drive is a lot more powerful than the original setup so I added the DEI 535T control box:

This model replaces the superseded 530T. This box switches off the system if it senses resistance. No more decapitations or crushed fingers. It automatically senses when the window has reached the end of its travel and switches off. No more binding of motors and overtensioning the system. I think that is part of the reason why the original lotus system kept failing.

It also adds features such as one touch up/down for two windows. If you have an alarm it can be wired to automatically close all the windows by tapping into the alarm trigger wire.

Autoloc also makes a control box but this box was cheaper and seemed to offer more functions.

[RogerFrench]

This is excellent stuff! Well done.
As a suggestion, maybe for anyone else who tries this, wouldn't bundy tube as used for windscreen wipers be a better bet than copper? It's made for that kind of job.

[yellowelan]

I've never seen or used bundy tube so can't comment. You can get plumbing copper pipe easily. I bent mine without a pipe bender without difficulty.

[yellowelan]

This is the wiring diagram for the 535T. Wiring was quite straight forward. You end up deleting the earth to the motor. The hardest part was getting to the window switch without taking apart the dashboard.

[Spyder fan]

What's wrong with the original system?

It works fine on my Duratec engined S4



Nice work, keep it up yellowelan, we need modifiers here who are not afraid to question the need to keep it original.

[RogerFrench]

I've never seen or used bundy tube so can't comment. You can get plumbing copper pipe easily. I bent mine without a pipe bender without difficulty.

Bundy tube is used in your Elan - it's the tube that connects your windscreen wiper motor and wheelboxes.

[S3FHC]

Congratulations on your work!
You are obviously determined and have achieved the mod despite the hurdles and set-backs..
(many would have given up!)

[yellowelan]

Its been several months since I installed the "new" electric window system. The worm drive has been working perfectly and I have not had any issues. The single touch up/down control is very handy.

[reb53]

Out of curiosity, and so I can keep an eye out for parts, what parts did you originally need for your windows, and were unable to obtain ?