I am rewiring my car. I noticed, to some slight annoyance, that he brake lights only work when the ignition switch is on. I have completed everything except the tail light harness. I am thinking of second guessing the original engineers and changing the power source for the brake lights so that they work at all times. I am just trying to wrap my thought process around the reason why they decided to put the brake lights on the ignition switch. Modern cars are not this way.
What is the harm, other then authenticity, in switching them? I think, for the sake of safety, it is better to have them wired direct and not through the ignition switch.
Am I wrong?
My question is why would you want them to work with the ignition off? I see no advantage to that and two disadvantages. It is possible to run down the battery if the brake lights somehow get turned on while the car is parked and the original wiring diagram is no longer accurate, that can cause some confusion when troubleshooting.
Both of those are minor problems but still problems.
I am going to leave it as is. Funny thing, the radio is wired to work at all times.
Those brake pressure type light switches do have a tendency to occasionally stick ON. If wired to work direct without ignition, you could easily find yourself with a dead battery some morning!
Quote from: pauldridge on October 21, 2013, 09:43:13 PM
Those brake pressure type light switches do have a tendency to occasionally stick ON. If wired to work direct without ignition, you could easily find yourself with a dead battery some morning!
Now this is the most informative answer I have had for this and a good reason why.
Quote from: Bob Hoffmann CLC#96 on October 21, 2013, 11:21:41 PM
Guys, Sorry but you're all incorrect. ALL cars have the brake lights work with the ignition off. Go check your cars, old & new.
Bob
I agree, or thought so, however the function on the old harness, and confirmed with the wiring diagram, the 1938 Sixty Special brake lights only have power when the key is in the run position.
I just rewired over the past two days and wired it exactly the same. Still don't work unless the car is on. I think I might swap the power supply over and tag the change under the dash for any future electrician/mechanic that might work on the car. This change puts less points of failure between the battery and the brake lights.
(https://forums.cadillaclasalle.club/proxy.php?request=http%3A%2F%2Fceretti.com%2Fcaddy%2FSchematic-Brake-Power-Revision.jpg&hash=202d98ac4747b5cb013d819629de3c32f9699d69)