TheSamba.com :: View topic

Sun Jul 14, 2024 7:43 pm

I'm not an electrician by nature, and have often been miffed about the sometimes random nature of the tail lights.

I read through several pages of helpful suggestions, and then went to my 57 and tried simplifying even further. Here's my suggestions:

The single bulb has two filaments: the "normal" brightness are the driving lights. The "very bright" filament is for the brakes and turn signals.

Get the tail light ass'y off the car, and remove the bulb holder. Set up 2 test leads (neg & positive) from your battery. You can do this just sitting near your back seat & battery. Hold the neg lead on the base of the bulb holder. Touch the positive lead to one of the "terminals", and then the other. One terminal should be "normal" brightness . . . that's your driving lights. The other terminal is the much stronger/brighter brake and turn signal filament. You also just proved that your bulb is working OK.

You can now see which post w/screw goes to the driving light filament. That is the white wire. The remaining post w/screw is for the black wire (which should have a tracer denoting R or L side. However, if it is dirty or old, you may not be able to see the tracer. Black wire is for brakes and turn signals.

LAST HINT: BEFORE assembling the whole thing back onto the fender, which is a PITA, test it outside the car. All you need to do is leave the B and W wire where you have them, and use a jumper wire from the light bulb base to a ground (I used a bumper bolt). That gives you a complete circuit.

Test 1: Key off. Pull the light switch out to the first click. . You should have running lights.

Test 2: Key on. Put the turn signal in position, the tail light should blink.

Test 3: Key on. Jam the brake pedal with a stick or something, and the brake lights should work.

CAP'N OBVIOUS: While you're doing all this, clean the base of the bulb, particularly the brass base and the terminals. Clean the bulb holder. Clean the contact spring. A wee smear of dielectric grease every 45 years of so often helps, especially on the 6V systems. Steel wool or a small brass brush works well for this.