Head light dimmer switch modification, with pics!

[Doughnut]

Hey guys.
Thought I might post this little write up showing how I bypassed the dimmer switch potentiometer (variable resister inside the light switch) so that your dash lights are at full brightness permanently.
Please note that this write up is specific to facelift e30's.

Step 1.
Remove your light switch.

Step 2.
Locate pins #2 and #6. (Numbers are kindly stamped on the inside of the plug)



Step 3.
Flip the switch over and remove the metal cover by prying with a flat blade screw driver.
Then, with reference to the front of the switch, mark pins #2 and #6 with a marker so you don't accidently solder the bridge wire to the wrong pins.



Step 4.
Solder the small bridge wire. I found that "tinning" the ends of wire and the back side of the pins first made it easier to apply. Take your time with this as you don't want to apply too much heat into the PCB.



Step 5.
Place the metal cover back in place and enjoy never having to rotate that annoying dimmer knob ever again.



Cheers guys.

[harv]

You must live where all the roads have street lights.

John

[evilnickwong]

I've always wondered how to do this as I too thought that a 15-20 year old potentiometer might not be able to give full voltage to the dash lights. Thanks!

[Gadea]

Dude, that´s awesome! I´ve trying to find a way to do this lately. I knew those pins give the difference in voltage to the instrument light circuit but did not know you could "access" them by simply removing the back cover. Do you know the "mapping" of the other pins as well?

[Doughnut]

Dude, that´s awesome! I´ve trying to find a way to do this lately. I knew those pins give the difference in voltage to the instrument light circuit but did not know you could "access" them by simply removing the back cover. Do you know the "mapping" of the other pins as well?

No, I didn't take the time to see where the other pins went but looking at the underside of the PCB and where each track goes would quickly make sense in relation to the position of the switch.

I just think this is a far nicer and professional way than cutting the two wires on the other side of the plug (mutilating) and joining.

[Gadea]

my car is also late style (1991) but the switch looks different "inside", below the metal cover.