Faulty Flashers

The flasher can should be a 3 pronged unit with each prong being labeled B, L, and P.

Prong "B" should have a green wire coming into it with a constant source of voltage right from the fuse box, with the ignition key in the on position. So you should meter 12VDC between earth and this point. If you don't have 12V there, either your fuse is blown, the ignition switch is defective, or you have a bad wire/connection in the circuit somewhere up to that point, the last being the most likely.

Prong "L" should have a green wire with a brown tracer leaving it and going to the center post of your dash single pole double throw blinker switch (SPDT) . You should have 12VDC there also with the key "on". If not, you have a problem between the flasher unit and the toggle switch in either the wiring/connection or the flasher unit itself.

If you have 12VDC at the center post of the dash switch and nothing going through the switch when you flip it either direction, you have a faulty toggle switch. If you're not fussy about originality, you can get a new switch at Radio Shack for about $4. If you get a new switch, it must be a SPDT "Center Off" , otherwise, your left or right signal will be on all of the time, assuming you get it working. It should be rated for at least 4 amps as you have two 21 watt bulbs working at any one time. 42W / 12 VDC = 3.5 amps.

Prong "P" should have a light green wire going directly to the turn signal indicator lamp on the dash.

When you flip the dash switch either direction, you are sending current through the switch and out towards the signal lights themselves on either side of the car. The current seeks its ground through the filament of the lights, thereby completing the circuit. If it can't complete the circuit, the flasher won't work. So you could have a wiring/connection problem downstream from the switch, but unless it affected all four turn signal lamps, I doubt that is your problem.

If you still don't get it to flash, I suspect the flasher unit itself is faulty. You could take a 12VDC test lamp and connect it between prong "L" of the flasher unit and ground (after removing the green wire with the brown tracer). If the test lamp doesn't flash, then it's probably your flasher. If it does flash, then I'd say it's in the switch area.

Hope that helps you.

contributed by: Dave Strickler