Brake Light Switch [Archive] - SaabCentral Forums

: Brake Light Switch

3rd May 2004, 07:03 AM
How long should the plunger on the brake light switch be? The reason I ask
is my brake switch has turned hair-trigger on me yesterday and consequently
boost cut over anything other than a perfectly smooth road. I found I had
to pull the brake pedal up with my foot otherwise the brake lights would
stay on and basic boost situation on the turbo.

I removed the brake light switch and inspected it. The plunger was about 4mm
long and given a little jimmying seemed to pop out and bit more, expending
it to about 6mm long. I re-fitted the switch and it was okay for a while,
but returned to a hair-trigger action within a few minutes of driving.

I read in the Haynes that there should be 10mm travel on the brake pedal
before the switch would click, so I packed up the flange that holds the
switch closed with a 5mm shim. This seems to have done the trick, but I
can't help thinking that the plunger on the switch should be longer and
therefore more travel on the brake pedal would be required to unload the
switch, causing the brake lights to operate.

To return to my question: How long should the plunger on the brake light
switch be? Do I need a replacement?

BTW, I don't have cruise control - there's only one switch down there in my Orca.

3rd May 2004, 08:15 AM
WD40 - the cure for all ills of this sort. 8)

3rd May 2004, 10:02 AM
You can sort of flick the switch to get the plunger to come out on it's splines, it must be some sort of interference fit. I just put my switch back on and the force of the pedal returning self-adjusted the switch plunger to the correct length!