356B, 1962 electrical, 12V

[Roscoe Stimpson]

I recently starting having issues with #1 8 amp fuse blowing. The #1 fuse controls the turn signals and brake lights. It does not happen right away. Usually after few days and driving it a few miles. Is it possible to have a short in the brake light switch? I have checked the wires to tail lights, they look ok. Any help will be appreciated.

[John Brooks]

Use a multimeter and measure the resistance on the output side of the fuse block with the fuse removed to ground. then remove the bulbs one at a time. If the lights still work, the short will be in parallel with a bulb. The bad circuit resistance, will increase to a high resistance but not completely open, with no filament in the circuit. The bulb is 2-3 ohms, your short is probably about 10k to ground.

When you find the suspected bad circuit, use the amp function, put the meter in series and look for a current draw less than an amp. With no bulbs in the circuit.

If it's the switch it will start and stop as the switch is manupiated

[Mervyn Hyde]

You suspect that it is the brake/tail light? If so it maybe be one go the older sprung connectors in the socket that has been damaged or popped out. You can buy new 'pigtails' (sockets) for those for a couple of dollars and solder them in. If it is the turn signal switch then that is more difficult of course.

[Roscoe Stimpson]

Thanks, the fuse blowing started a short time ago. This first time when I was still using bulbs. I have since replaced the tail lights with LED units. I will pull both of these and check the sockets. I will also check the back up light switch and wiring since it is also tied to #1 fuse.

[Greg Bryan]

I believe your T6 B also has the Back-up lights on fuse #1. You could remove one wire at a time from the #1 fuse until you isolate the problem circuit, leaving the brake lights till last, of course.
So, remove the gray/brown wire first (back up light) and drive the car as before and see if the fuse still blows. If it doesn't blow, the problem is in the B/U circuit; check at the B/U light switch on the trans and at the light fixture below the bumper.
If still no joy, then remove the turn signal wire from the bottom of #1 fuse and repeat the drive. Both the turn signal wire and the brake light wires are black, however, so you have to experiment to find the right wire. Also, the brake lights and turn signals meet at the turn signal switch, and share the same wire back to the rear light fixture. Check the insulation on the in-line connectors around the steering column for the turn signals and brake lights
The turn signal flasher is also a possible, and the indicator light circuit could also be grounding somewhere between the flasher and where it pushes into the instrument.
I would start with the terminations at the lights to see if there is a loose wire or part of the light fixture that is allowing a ground and blowing the fuse. In rare cases, the wire insulation may be chafed off, but usually the problem is at the connections.

[bob lerche]

Recently I was having a similar problem with my 6V 1962 coupe after replacing my bulbs with LEDs and installing the LED flasher relay from Zims. I determined that after a while the flasher unit would work its way out of the receptacle slightly and blow the #1 fuse. My fix was to spread the male spades on the flasher unit to make for a slightly tighter fit and the problem is now gone.

[Roscoe Stimpson]

Thanks for all the responses. I relocated the ground lug on each of the LED tail lights. I put it under the part of the rubber tail light seal where one of the screws is located which holds lens in place. I also re-tightened the ground connection at the electronic flasher. Based on one of the above comments I slightly spread the one of the 3 pins of the flasher unit itself. Fits nice and tight. Since I have a lift I will check the wiring on the back up light switch. I do have one question, what does the dual 8/15 rating on the fuse mean? If I need to, I will dig a bit deeper into the wiring. I can possibly check the current draw at the fuse when the turn signals are on.