Bartamos, The turn signal switch is downstream of the flasher, so putting power thru the flasher to the 87 terminal, and to the coil terminal just switches the power to the brake light from the brake pedal switch to the flasher (both being powered.) But with nothing connected to 87, the relay just turns the brake light off in time with the flasher fed power from the turn signal switch. It will be in opposition to the front light, which gets its power from the turn signal switch. That makes no difference, since they're on opposite ends of the truck. I bench tested it, and couldn't get my flasher to work, so manually flashed the power coming thru the turn signal switch. If I could have gotten my flasher to work, I think my result would have been the same for the originally wired configuration. The switching of the relay coincided with the power to the bulb from the flasher, so that turned the bulb ON and ON instead of ON and OFF. Not theory, but practical. Yes a vintage switch. Dual filament bulb makes no difference, it's just the brake/turn circuit. If the feed coming from the turn signal switch was constant, then the original configuration might work, but the turn signal switch output is SUPPOSED to be intermittent. Trust me. It WORKS. {on edit] No it doesn't. No rear flashers unless the brake pedal is depressed (not good!)
Last edited by klhansen; 03/20/20248:34 PM.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
