turn signal/brake switch?

I was pulled over for a speeding ticket last week. On top of the
ticket, I got another equipment repair ticket for non-working
brake lights. I guess it wasn't my day.

I have a 95 Lumina. 3.1L

The top center dome brake light works, but the two lower lights
do not come on when the brakes are applied. I checked the bulbs,
connections, fuses, and everything seems to be in order. Both
filment of the bulb comes on for turn signal/headlight respectively,
so the connection to the bulb themselves are good. I did some
research, and it seems that the turn signal/brake light switch
may be to blame here, as it is supposed to perform dual functions
and switch between brake lights and flashing turn signals, so if
it fails, the symptom would be as I had observed, that being
everything seems to work fine, but the 2 lower brake lights just
don't come on when the brakes are applied.

My question is, does this sound reasonable?

Also, what do I tell the parts department at the dealership I want?
turn signal/brake light switch?

BTW, where is this switch located? I don't normally work on cars,
but I'm an electrical engineer, so I figured that I should try to
work out an electrically related problem on my own car.

TIA for any help.

--
davewang202(at)yahoo(dot)com

Information below is supplied because you stated you are an electrical
engineer
and should know his way around electrical cirsuits and the hazards of
shorting
out DC circuits. Be careful!

The brake light switch should be located near the base of the steering
column,
at the brake pedal location. Look for a switch that is mounted so that when
the
brake pedal is not applied, the switch is being depressed by the shank of
the
pedal that is supended from the top. There should be two wires connected
at the back of the switch, they are spade connectors so you should be able
to pull them off the switch. One is a "hot" wire. The switch is a "plunger"
type switch.

You can short between these two wires with a jumper set or even a paper clip
if you make sure it can't be grounded on the body. Shorting between the two
wires
should turn on all brake lights. If it does, the switch is either out of
adjustment
or defective. The switch screws into it mounting bracket so you can adjust
it
by screwing it in out out, sometimes if it has been depressed too far, the
plunger
sticks in and that is the "off" postion.

Hope this helps...

"David Wang" <foo@bar.invalid> wrote in message
news:c2nfd7$7im$1@grapevine.wam.umd.edu...
> I was pulled over for a speeding ticket last week. On top of the
> ticket, I got another equipment repair ticket for non-working
> brake lights. I guess it wasn't my day.
>
> I have a 95 Lumina. 3.1L
>
> The top center dome brake light works, but the two lower lights
> do not come on when the brakes are applied. I checked the bulbs,
> connections, fuses, and everything seems to be in order. Both
> filment of the bulb comes on for turn signal/headlight respectively,
> so the connection to the bulb themselves are good. I did some
> research, and it seems that the turn signal/brake light switch
> may be to blame here, as it is supposed to perform dual functions
> and switch between brake lights and flashing turn signals, so if
> it fails, the symptom would be as I had observed, that being
> everything seems to work fine, but the 2 lower brake lights just
> don't come on when the brakes are applied.
>
> My question is, does this sound reasonable?
>
> Also, what do I tell the parts department at the dealership I want?
> turn signal/brake light switch?
>
> BTW, where is this switch located? I don't normally work on cars,
> but I'm an electrical engineer, so I figured that I should try to
> work out an electrically related problem on my own car.
>
> TIA for any help.
>
> --
> davewang202(at)yahoo(dot)com

Bob D <bobb60@yahoo.com> wrote:
> Information below is supplied because you stated you are an electrical
> engineer
> and should know his way around electrical cirsuits and the hazards of
> shorting
> out DC circuits. Be careful!

> The brake light switch should be located near the base of the steering
> column,
> at the brake pedal location. Look for a switch that is mounted so that when
> the
> brake pedal is not applied, the switch is being depressed by the shank of
> the
> pedal that is supended from the top. There should be two wires connected
> at the back of the switch, they are spade connectors so you should be able
> to pull them off the switch. One is a "hot" wire. The switch is a "plunger"
> type switch.

> You can short between these two wires with a jumper set or even a paper clip
> if you make sure it can't be grounded on the body. Shorting between the two
> wires
> should turn on all brake lights. If it does, the switch is either out of
> adjustment
> or defective. The switch screws into it mounting bracket so you can adjust
> it
> by screwing it in out out, sometimes if it has been depressed too far, the
> plunger
> sticks in and that is the "off" postion.

> Hope this helps...

Thank you very much. I have an inexpensive multimeter at home, and a
really fancy $2K model at work. I'll use them to check out the
circuits.

As to the location of the switch. A light bulb just came on in my head.

The car was serviced in December by a local garage because the brake
pedal was set too low, and they "fixed" it. Grrrrr...

I guess they did something so that the switch no longer functions.
Ofcourse, no one noticed except the cop that pulled me over.

Thanks again.










--
davewang202(at)yahoo(dot)com