Freelander tail door windown on armored cars

[bmoraes]

I have an armored Freelander (2004). Due to the thick armored glass the tail window window only moves about 1-1 1/2 inch (it has a telescopic cylinder to help the motor raise the window). Whenever I have to disconnect the battery the tail window looses it calibration.

The usual calibration procedures do not work, I guess because the window only travels a very short distance, and probably the control unit thinks there is an error. To get it calibrated it is necessary to remove the glass, put a "normal" glass, calibrate it and refit the armored glass. Quite a lot of trouble and work, and sometimes difficult to get it right.

Questions:

1) Is there a way to get the tail window calibrate if it only has 1 inch to move?

2) Is there a way not to loose the calibration when removing the battery?

I thought about something like a modified "control unit" or a "backup" battery for keeping the memory but I don't know where to start.

Any ideas are welcome. Thanks, Bruno

[FridgeFreezer]

Whilst it would be fairly simple to rig the sensor to be manually operated, I'd beware of faking the calibration, you don't want it trying to drive the glass through the roof or anything silly.

[bmoraes]

Do you mean rig the sensor by bypassing the Control Unit? Or any ideas to calibrate it without moving it all the way down and up again?

[errol209]

You could use a "memory saver", they are sold to protect your radio memories when you take the main battery off, but they won't last long in use.

Not an easy fix, but you could add a small rechargeable battery fed from the battery positive through a diode, and then feed the ECU / BECM (whatever a Freeloader has) through another diode (the diodes prevent your add-on battery and ECU / BECM supply trying to supply full starting current )