Daves55Sedan
Well-known member
The auto parts store doesn't sell motorcycle parts, so I need to go down to the motorcycle shop to get the Harley switch. It's just toooooo cold. Brrrr.
Low-pressure brake light switch
- Thread starter Daves55Sedan
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Daves55Sedan
Well-known member
My '55 has stock master cylinder and GE 1154 (6-volt) bulbs. Each bulb stoplight element uses 17 watts. Multiplied by two elements = 5.66 amps, so the switch needs to be rated for at least 8 amps.
Thanks for mentioning the relay. I will try to find out if the Harley switch is rated this high. If it is not, I will need to add the interposing relay (which I don't want to do), or go to a mechanical switch with an 8 or 10 amp rating.
If you had a 12 volt electrical system, the ampere rating would be reduced by half or 2.83 amps for two bulbs. But my car still has 6 volt electrical system.
Daves55Sedan
Well-known member
I went down to the motorcycle parts shop today and got the Harley Davidson brake light switch with heavy duty contacts and straight blade push-on terminals. Their spec book did not actually define the contact rating but I am sure it is better than 3 amps. So I will use it for the Courier which was converted to 12 volts. But if the switch in my '55 car goes bad, I will probably need to go another route since the car still has 6 volt electrical system.
Daves55Sedan
Well-known member
Paul I'm glad you showed that switch mounting. Now I know I will never use that. My pedal almost goes to the floor to stop the car. I can't believe you have your brake shoes adjusted so tight so the pedal doesn't have to move so far down. Think of all the friction at the brake drums.
That's why I say, if I did opt for a mechanical switch it would need to work the opposite way yours does (such that the contacts close when the button is released). That means you would need to have the switch mounted fixed upon the brake pedal arm, then you would also need to mount a second custom made bracket to act as a standoff for the switch plunger, thus when the pedal is pushed down, the plunger releases, closes the contacts in the switch and brake lights come on. When the pedal is released, it springs back and pushes to plunger on the switch, opening the contacts.
That's why I say, if I did opt for a mechanical switch it would need to work the opposite way yours does (such that the contacts close when the button is released). That means you would need to have the switch mounted fixed upon the brake pedal arm, then you would also need to mount a second custom made bracket to act as a standoff for the switch plunger, thus when the pedal is pushed down, the plunger releases, closes the contacts in the switch and brake lights come on. When the pedal is released, it springs back and pushes to plunger on the switch, opening the contacts.
thumbs up for this! I have this set up on my 56 fairlane. just a little aluminum bracket near the brake pedal under the dash.
paul2748
Well-known member
Your wrong on the set up. The button when pushed in disconnects the circuit. It rests at the front of the brake arm, not the rear. When the brake is pressed by as little as an 1/8 to a 1/4 inch (releasing the button) so the circuit is made and the brake lights come on.
I put the same type of set up on my 64 Fairlane (last year for hydraulic switches) and there is a kit that is basically the same design for early TBirds.
I put the same type of set up on my 64 Fairlane (last year for hydraulic switches) and there is a kit that is basically the same design for early TBirds.