MK3.5 Auto Windows - Does anyone Know How They Work?

Maybe a question for Rob or anyone else with some detailed electrical knowledge?


I would like to mod the windows on my PRHT and add an ‘auto’ up mod. I have looked at the schematics for both the RX8 and ND and they have limit switches on the window regulators that are wired to the window control module.

Looking at the NC schematic it doesn’t appear to have the limit switches wired up to the window controller (also looking at secondhand regulators on Ebay it looks like the limit switches are just looped together, maybe this is a clue?). Does anyone know how the one-touch function detects that the windows are fully open so that it can remove the power?



From the Smart Top website:

Important functionality note:

For technical reasons it is not possible to fully lower the windows or raise them at all. Mazda decided to go with a very basic design which completely omits a control wire for raising the windows and only has one single wire that, if activated, drops the windows by a few inches. Our module will operate the windows along with the top exactly the way it works from the factory. When closing the top from the center console button, the windows stay down and need to be closed using the window switches.

I think they sense current increase when the motor is stalled.


Thanks for the SmartTop quote Mac :smiley:


That sound quite feasible Rob, time to buy a second-hand window switch and take it apart :slight_smile:





Does this help? Disassembling a switch isn’t really necessary IMHO, the drawings show what the switch does.Also the limits appear to be wired to the controller (see figs 22 to 25) on this link -

Gerry yes it does :wink: and thanks for the mellens link   (love that site and have downloaded a lot of the other PDFs :smiley: ).  

I still think that I will need to dissect a switch because the figures that you have linked seems to concur with the other schematics that I have looked at and don’t show the limit switches being connected to the window controller.


Will report back with my findings…





There aren’t any “limit” switches. 

In the basic NON-PRHT Fig 22, A&D go to one window motor and B&G to the other.  The P/W CM senses the current and if there is too much because it stalls at the end of travel it then stops supplying power.  When you let go of a switch, ie it returns to centre position, then the contacts rest as shown in the diagram with each of A,D,B,G connected to ground, ie J, and the CM (Current Module) has the stall overload removed and can reset.

In the PRHT Versions Figs 24 (25), the principle is repeated but with relays to carry the current and these are operated both by the manual switches, and the PRHT computer etc via the bus on 2B&2C (A&H). Here D&F go to one window and I&J the other and P/W CM still senses the current etc.

The interesting bit is in deciding which switch you have, with two plugs (Fig 24) or one (Fig 25), The software will be significantly different, with interesting possibilities one can only speculate on until playing with it with help of a 'scope etc.