Switchable power booster for vintage Ferrari power windows

Discussion in 'Automotive Electronics' started by nicktruman, Feb 9, 2019.

  1. nicktruman

    Thread Starter New Member

    Feb 4, 2019
    I need some help please. I have a 41 year old Italian sports car, as per all Italian cars of this age the electrics are woeful! The resistance of all the wires and connectors has increased meaning that there is rarely 12v where it is needed. For instance the electric/power windows only have between 8 and 10v at the motor.. and this is a real issue as the windows barely raise or lower. Like all owners I have changed all that is possible, upgrading fuse boxes, relays and so on.

    The power window motor has 2 wires and depending which one is +ve the window goes up or down. The motor drives a worm drive, which in turn drives a cable winch which pull up, or pushes down the glass. It is possible to buy power boosters, but as with everything else on my car, I want to do it myself.

    Both power windows are protected with a single 10 amp fuse so I guess the maximum drain can be no more than 5 amps each, as the windows an be used together.

    I have seen many 12v 10 amp boosters on ebay, but I am not sure how I could cater for the switching +ve supply.

    Can you help me please?
  2. crutschow


    Mar 14, 2008
    Can't you just switch the 12V from the booster, the same way the 12V from the battery is switched now?
  3. cork_ie

    Active Member

    Oct 8, 2011
    This guy http://www.birdman308.com/service/windowservice/index.html has an excellent tutorial covering your problem. Ricambi in the USA used to sell such a product for the Ferrari but they are no longer on their website which is a bad omen.
    There is also another company here: http://fastferrariwindows.com/index.html who sell something similar.
    Banging more power into your motors with stiff/ poorly lubricated/ worn, mechanicals will just heat the motors, increase the resistance and give you poor back EMF and high current draw in a vicious circle.
    I know very little about classic Ferraris but do know that Landrover and several others used cable drives for windscreen wipers and they had very similar problems.
    The cure was always to remove the cable and wash it clean with petrol , clean the tubes, and fix any wear in the mechanical parts of the drive. Lightly grease with a soft lithium based grease. Never use heavy axle or steering linkage greases, they are too thick. Then clean the motors and oil the bushings/bearings. If the motors have been severely overheated you will need to check the motor armatures and that the magnets have not lost their strength.
    I would also use some silicone oil, designed for rubber on the slides and adjust the runners so that the glass doesn't kick sideways - especially going up. If the mechanicals are all working correctly, then you can consider extra measures.
    I think the very best option is to feed 2 new 2.5mm2 cables into each door, directly from a known good 12V+ power and earth source. Fuse the 12V+ at source and use a pair of cube relays to make a H bridge in each door. You can use the existing circuit in the door to drive the relays.If you are unsure of how to wire it all up let us know and we will help.
    Last edited: Feb 9, 2019