Turn signal, hazard and dash lights flash on left turn signal

[Blackburn]

Built a Mark 3.1 and have had it in the road over 5 years. Went for a ride, battery low, stalled and had to push start. Since then, the left turn signal makes the hazard and dash lights flash when I use it. What happened and which way do I go to fix it? Thanks

[RickP]

Oh boy. Sorry to hear your troubles. I would first check all your ground locations. Specifically the one for the dash harness. Hopefully it's accessible. Are your turn signals routed through a relay?

[2bking]

If you have the diodes in the circuit for separating the hazards and turn signals, push starting may have caused an overvoltage condition that shorted one of the diodes. Or the low voltage of the battery caused more current to flow through the diode than what it was rated for. I don't think a bad ground would be the culprit unless it was coincidence that it showed up at the same time the battery went low.

[michael everson]

What turn signal lever are you using? Seems weird that the dash lights would flash too.
Mike

[edwardb]

I agree it's some kind of backfeed condition. The explanation from King makes a lot of sense, assuming you have diodes in the circuit. That would be the first place I would look.

During my last build, I attempted to install a turn signal indicator/buzzer from Watson's Streetworks. Unfortunately, it introduced a backfeed condition into the circuit. Either turn signal also flashed the hazards and the dash lights. Exactly what the OP is describing. I chased it for a while, but then just gave up and took it out of the circuit. All returned to normal. Backfeeding can take some strange paths.

[Blackburn]

Thanks for the responses. I am using a Lucas type switch for the turn signals. I did install diodes and maybe I should start there?

[edwardb]

Thanks for the responses. I am using a Lucas type switch for the turn signals. I did install diodes and maybe I should start there?

Yes. Suggesting to look at the diodes. If it was working before and now it isn't, then obviously something failed. The diodes are a good candidate because if they are shorted due to an overvoltage as King described, they would allow a backfeed condition which is what you're describing. Diodes can also fail open, but then something wouldn't work at all vs. the backfeeding. You can do a pretty basic test on the diodes with a VOM. But to be accurate should be taken out of the circuit. Maybe at that point just makes sense to replace if you have some some on hand.

[Blackburn]

Thanks. That is where I will start