Third brake light out mystery- 96 Buick Century

Are all the rest of the lights working ok , signals ,4 ways etc. ?
This could be the start of signal switch problems. Very common in
those cars. Been there myself twice.

On Wed, 28 Mar 2007 21:41:02 -0600, "John M. Darnielle"
wrote:

>My head is sore from all the head scratching- what am I missing?
>
>The third brake light doesn't light, the left and right brake lights are
>fine. First, I put a brick on the brake pedal.Open the light, replace the 2
>bulbs with 1156's like the owners manual says- doesn't work. Wait- on the
>housing it says to use 1141's, try that, still doesn't work. Check the
>voltage- I only get power when the ignition is on, and I only get 6 volts. I
>try the voltmeter on a regular brakelight, get 12 volts anytime the pedal is
>depressed. Anyone know what I'm doing wrong? Thanks!
 >> Stay informed about: Third brake light out mystery- 96 Buick Century 

Hi! All the other lights work great. I get the same 6 volts measuring from
contact to contact as I do from hot contact to ground. ???


"JRL" wrote in message

> Are all the rest of the lights working ok , signals ,4 ways etc. ?
> This could be the start of signal switch problems. Very common in
> those cars. Been there myself twice.
>
> On Wed, 28 Mar 2007 21:41:02 -0600, "John M. Darnielle"
> wrote:
>
>>My head is sore from all the head scratching- what am I missing?
>>
>>The third brake light doesn't light, the left and right brake lights are
>>fine. First, I put a brick on the brake pedal.Open the light, replace the
>>2
>>bulbs with 1156's like the owners manual says- doesn't work. Wait- on the
>>housing it says to use 1141's, try that, still doesn't work. Check the
>>voltage- I only get power when the ignition is on, and I only get 6 volts.
>>I
>>try the voltmeter on a regular brakelight, get 12 volts anytime the pedal
>>is
>>depressed. Anyone know what I'm doing wrong? Thanks!
>
 >> Stay informed about: Third brake light out mystery- 96 Buick Century 

Hows the connection where the wire harnesses plug together? Clean?

h
 >> Stay informed about: Third brake light out mystery- 96 Buick Century 

Hi- Yes, and just to make sure I cut it tested voltage there as well, got
same 6 volts. I put it back together with wire nuts. I'm still stumped.

John
"Harry Face" wrote in message

> Hows the connection where the wire harnesses plug together? Clean?
>
> h
>
 >> Stay informed about: Third brake light out mystery- 96 Buick Century 

"John M. Darnielle" wrote in message

> Hi- Yes, and just to make sure I cut it tested voltage there as well, got
> same 6 volts. I put it back together with wire nuts. I'm still stumped.
>


Most likely cause of reduced voltage is a poor connection, which causes
high resistance. You may need to follow the wire to the front of the car to
find the problem area. A wiring diagram and a good understanding of how to
diagnose eletrical problems are needed. Electrical problems can be
extremely hard OR very easy to fix but you won't know which one it is until
you actually find the problem. My advise would be to check the easiest
connections you can get to at each end of the wire in question first. If you
don't find the problem at either end you will have to follow the wire from
one end to the other, which may not be as easy as it sounds.
 >> Stay informed about: Third brake light out mystery- 96 Buick Century 

"John M. Darnielle" wrote in message

> Hi- Yes, and just to make sure I cut it tested voltage there as well, got
> same 6 volts. I put it back together with wire nuts. I'm still stumped.
>

Did you try to apply a good solid ground to it yet? Bad grounds are the
leading cause of bizarre lighting problems in cars. Low voltage like you
are seeing is quite common as circuits feed back when grounds are bad.

--

-Mike-
mmarlowREMOVE DeleteThis @alltel.net
 >> Stay informed about: Third brake light out mystery- 96 Buick Century 

Hi- I think I'll try that next. I didn't ground it because I was still
getting 6 volts when I measured from hot wire to a good ground, as well as
from hot wire to ground wire. If that doesn't work I'll try tracing the
circuit forward. Thanks!

John

"Mike Marlow" wrote in message

>
> "John M. Darnielle" wrote in message
>
>> Hi- Yes, and just to make sure I cut it tested voltage there as well, got
>> same 6 volts. I put it back together with wire nuts. I'm still stumped.
>>
>
> Did you try to apply a good solid ground to it yet? Bad grounds are the
> leading cause of bizarre lighting problems in cars. Low voltage like you
> are seeing is quite common as circuits feed back when grounds are bad.
>
> --
>
> -Mike-
> mmarlowREMOVE.RemoveThis@alltel.net
>
>
 >> Stay informed about: Third brake light out mystery- 96 Buick Century 

"John M. Darnielle" wrote in message

> Hi- I think I'll try that next. I didn't ground it because I was still
> getting 6 volts when I measured from hot wire to a good ground, as well as
> from hot wire to ground wire. If that doesn't work I'll try tracing the
> circuit forward. Thanks!
>

Sorry - did not realize you had measured from the hot lead to a known good
ground. Going to another known good ground won't help you much.

--

-Mike-
mmarlowREMOVE.DeleteThis@alltel.net
 >> Stay informed about: Third brake light out mystery- 96 Buick Century 

Thanks to everyone who chipped in to help solve this- it turned out to be
the brake light switch.

John

"Mike Marlow" wrote in message

>
> "John M. Darnielle" wrote in message
>
>> Hi- I think I'll try that next. I didn't ground it because I was still
>> getting 6 volts when I measured from hot wire to a good ground, as well
>> as
>> from hot wire to ground wire. If that doesn't work I'll try tracing the
>> circuit forward. Thanks!
>>
>
> Sorry - did not realize you had measured from the hot lead to a known good
> ground. Going to another known good ground won't help you much.
>
> --
>
> -Mike-
> mmarlowREMOVE.RemoveThis@alltel.net
>
>
 >> Stay informed about: Third brake light out mystery- 96 Buick Century