|
Sponsored Links (Register now to hide all advertisements) |
|
|
Thread Tools | Display Modes |
08-09-2023, 04:20 PM | #1 |
Senior Member
Join Date: May 2010
Location: Oro Valley, AZ
Posts: 435
|
Brake Lights Dilemma
On our '34, when we have the brake lights on and then when the headlights are turned on the brake light goes off. This only happens on one brake light, the other performs normally. In studying this problem, we observed that only one filament was being used by both. We changed out numerous double-filament bulbs and they all performed the same, the brake light and the head light used that same filament on that side. What do we have to do to correct that and not have that brake go off when the headlights are on?
|
08-09-2023, 05:51 PM | #2 |
Senior Member
Join Date: May 2010
Location: So Cal
Posts: 8,755
|
Re: Brake Lights Dilemma
Are you sure it's the brake light and not the tail light that's going out?
If it's the tail light it could be a grounding problem. Only one head light filament should be on at a time. One filament is low beam and the other is high beam. |
Sponsored Links (Register now to hide all advertisements) |
|
08-09-2023, 06:58 PM | #3 |
Senior Member
Join Date: May 2010
Location: Midland Park, NJ
Posts: 3,982
|
Re: Brake Lights Dilemma
It sounds like a grounding problem. Run temporary grounds to each taillight housing and see if that solves the problem
__________________
48 Ford Conv 56 Tbird 54 Ford Victoria |
08-09-2023, 08:48 PM | #4 |
Senior Member
Join Date: Jan 2019
Location: Chicago
Posts: 732
|
Re: Brake Lights Dilemma
Really confusing when you say headlights when you are talking about the taillight. Yes headlights and taillights come on together, but the headlights have nothing to do with this problem.
As said above, this is a classic symptom of no ground at the bad light's socket. Brake light is using the taillight filament and wiring to find ground at the other side's good socket. Only the taillight filament lights up because it is smaller. And then this strange path to ground gets blocked when taillights have power on. To fix this, look at how the socket is attached. Needs clean, tight, metal-to-metal contact between the socket and truck body. Sometimes it's a coat of paint breaking the contact. Last edited by JayChicago; 08-10-2023 at 02:01 AM. |
08-10-2023, 05:32 AM | #5 |
Senior Member
Join Date: Sep 2013
Location: Dighton, Mass
Posts: 1,230
|
Re: Brake Lights Dilemma
Your best friend is a simple test light
|
08-10-2023, 06:16 AM | #6 |
Senior Member
Join Date: May 2010
Posts: 4,751
|
Re: Brake Lights Dilemma
Sponsored Links (Register now to hide all advertisements)
|
08-10-2023, 09:45 AM | #7 |
Senior Member
Join Date: May 2010
Location: Oro Valley, AZ
Posts: 435
|
Re: Brake Lights Dilemma
Thank you guys for your responses We will look at the grounding. There is some confusion the way I described the problem when we turned the headlights on. We step on the brake pedal and the brake lights come on. With brake lights on we turn on the headlights. One brake light turn off. Do you think this happens because improper grounding on that one tail light? The other brake light works properly with the headlights on.
|
08-10-2023, 10:25 AM | #8 |
Senior Member
Join Date: May 2010
Location: So Cal
Posts: 8,755
|
Re: Brake Lights Dilemma
The most likely cause is a bad ground.
|
08-10-2023, 10:45 AM | #9 |
Senior Member
Join Date: Jan 2019
Location: Chicago
Posts: 732
|
Re: Brake Lights Dilemma
|
08-10-2023, 01:01 PM | #10 |
Senior Member
Join Date: May 2010
Location: Oro Valley, AZ
Posts: 435
|
Re: Brake Lights Dilemma
Thanks for all you help. Off to find the ground problem
|
|
|
Sponsored Links (Register now to hide all advertisements) |
|