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Re: Brake Lights

To: PVANDAL@aol.com
Subject: Re: Brake Lights
From: Steve Benelisha <steveb@verity.com>
Date: Fri, 11 Oct 1996 09:39:41 -0700
Cc: triumphs@autox.team.net
Organization: Verity Inc.
References: <961011113723_124270465@emout14.mail.aol.com>
Hi-

  Usually, this class of problem is caused by the Ground Return path
being broken at the tail lights. What happens is the current passing
through the break light would like to return to the car body but 
can't. since the break light is a dual filament bulb (the other 
filament being the parking light) and has a shared ground, the 
return current has to go through the tail-light filament -> through
the car's wiring -> through the Headlight filament and then to the
cars body (ground). It does this because the this is the only 
path available. 

  One other clue is that your break lights should be a bit dim 
from the added resistance of the two extra filaments in the ground
return path.

  When the parking/headlights are on, the break lights stop working.
Why? Because as a lamp heats up, it's internal resistance increases
causing a drop in return current from the break lights.

 To test if this is the case, connect a (heavish) wire from the tail
light housing to a point on the body of the car that will provide
electrical contact. The break lights should then work normally and 
the parking lights should get brighter.

Good luck
-Steve
64.5 TR6

PVANDAL@aol.com wrote:
> 
> Does anyone know the reason why my brake lights do not work when my lights
> are turned on?   They work fine with the lights turned off.   Desparate in
> need of assistance to clear Ct inspection.
> Thanks in advance.......

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