Baffling Electrical Question - Brake Lights
Posted: September 11, 2011, 8:37 pm
I know electrical. I know how to read schematics - well, at least the kind our trucks have.
I.
Am.
Baffled.
Symptom: I noticed the brake lights do not work with the ignition OFF. I thought they did a long time ago, though. (They work fine with the key on.)
About 2 years ago, I replaced the '66 steering column with a '72. I put in a new replacement switch - for a '72, I think. I don't remember. Everything works properly except the brake lights when the key is OFF.
So to troubleshoot all this, I get out schematics to find how power is applied to the brakes.
All along, I have believed when others have said that the brake switch is powered through the turn signal switch.
Schematics say otherwise.
Tracing the wires says otherwise too.
Power is supplied to the flasher and the brake switch from a fused and switch circuit off the fusebox - not through the turn signal switch, at least as far as I can see.
Am I wrong?
Do the brake lights come on when the key is OFF?
If so, what wire supplies power to the brake switch for the brake lights?
Thanks for any and all help.
I.
Am.
Baffled.
Symptom: I noticed the brake lights do not work with the ignition OFF. I thought they did a long time ago, though. (They work fine with the key on.)
About 2 years ago, I replaced the '66 steering column with a '72. I put in a new replacement switch - for a '72, I think. I don't remember. Everything works properly except the brake lights when the key is OFF.
So to troubleshoot all this, I get out schematics to find how power is applied to the brakes.
All along, I have believed when others have said that the brake switch is powered through the turn signal switch.
Schematics say otherwise.
Tracing the wires says otherwise too.
Power is supplied to the flasher and the brake switch from a fused and switch circuit off the fusebox - not through the turn signal switch, at least as far as I can see.
Am I wrong?
Do the brake lights come on when the key is OFF?
If so, what wire supplies power to the brake switch for the brake lights?
Thanks for any and all help.