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Brake Light Switches 92 Astro

1248 Views 8 Replies 3 Participants Last post by  xtracold
So at the weekend a mate of mine noticed that my brake lights aren't coming on. Fuse/Bulbs are fine. I suspect the brake light switch has worn out, some fiddling over lunch today with the plunger on the switch and the brake lights come on again but it is sticky! Thinking i'll just replace the switch, but I notice that there is actually two? Anyone out there able to explain why there is two, is it just redundancy and if not which one it the actuall brake light switch?

It's a 1992 Astro LT.


1 - 3 of 9 Posts
Second switch may be for the cruise control dis-engage function. WIll probably have a vacuum hose also attached to it.
Slide switch has three positions:
Leftmost is "OFF" (turns cruise control system off)
Middle is "ON" (turns cruise control system on)
Right most is "R/A (RUN/ACCEL)" (push to this position to continue cruising at previously set speed)

Pushbutton on end of stalk is "SET" (press to set speed when cruise is on)
Press on brake to stop cruise control.

The rotary part is for the wipers but I'm pretty sure you figured that out a LONG time ago!
Next time you have the dog house off, check the vacuum line that comes off the cruise control vacuum servo for leaks or breaks. It runs form teh servo, right above the driver's side exhaust manifold, and then thru the firewall to the brake dump valve above the brake pedal.

The other possibilty is that the dump valve (the one on the brake pedal) is mis-adjusted and is keeping the vacuum from operating the servo to open the throttle.
1 - 3 of 9 Posts
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