Window Switch Repair

[jack.am]

Window switch not working? Carbon build up is likely the culprit.

1 - Remove and disassemble your window switch. Do not lose the little white things:

2 - Note the wiring order, though it is marked on the board, and desolder the pins for the switches:

3 - Disassemble the switch. Do this over a pot or similar container. It’s full of little bits and springs that will go everywhere:

The cross shaped tabs are little rocker contacts that are actuated by the switch through the little ball bearings in the white spring mounted cups.

4 - Clean the carbon buildup from both the removable contacts and the contacts inside the switch body. I used isopropyl alcohol for this:

5 - Re-assemble the switch. The best way I found to do this was :

— Put the contacts back in the body
— Put the ball bearings on the contacts
— Mount the springs and cups in the switch frame
— Gently clip the frame to the body whilst using a small pick to manipulate the ball bearings into the cups
— Have a cup of tea

6 - Re-solder and assemble the switch

 

[casey]

Good write up. I wrote up a similar process for repairing the RX-7 1st Gen window switches as poor window operation was frequently caused by carbon build up in the switches. The issue on the 1st Gen is that the full window motor current flows through the switch, so when the inductive motor load is turned off, there will be sparking at the switch contacts, leading to carbon build up. The solution, which I've subsequently carried out on my 1st Gen, is to install two heavy duty double-pole relays to take the motor current and remove the direct motor load from the less robust switch contacts.

I assume, seeing that carbon build up, that Mazda still carried on with relayless window switches to the 3rd Gen. The JDM wiring diagram seems to confirm this.

Picture of a disassembled Gen 1 window switch, before cleanup, note the horrible pitting on some of the contacts:

 

[jack.am]

That's interesting, my contact had very deep pitting as well as the carbon.

It's been on my list to give them their own feed to bypass the F100 box anyway, good time to pop a relay in.