Current flow control

Community Chit Chat
1

I’m sure you’ve all seen those lights that people put in their hitch receivers that light up when brakes or turn signals are used. I have one that’s run off the passenger side brake/signal light. This annoys me to no end, so I’d like to rewire the light so it will light when either the left or right turn signals and brakes are used.

With this rewire, the light would receive power from both lines at the same time when using brakes or 4 ways are on.

Will a diode, whether a Zener or Schotky work to prevent a back feed and still allow current flow at the same time? I’ve used them to prevent power reversal and such but never in a manner like this.

Thanks.

2

Hi banshee1a.

I’m not familiar with how those lights work internally, but I imagine that you could use some [diode logic to light the bulb when the correct conditions are met. You could even use relays if you wanted too.

If you go with diodes, you’re probably going to want to go with a rectifier type diode that’s rated a bit above the expected current draw of your lamp. If the lamp is incandescent rather than LED, get a diode rated 3 or 4 times the running current of the lamp.](Diode logic - Wikipedia)

3

TS-Chris:
Hi banshee1a.

I’m not familiar with how those lights work internally, but I imagine that you could use some [diode logic to light the bulb when the correct conditions are met. You could even use relays if you wanted too.

If you go with diodes, you’re probably going to want to go with a rectifier type diode that’s rated a bit above the expected current draw of your lamp. If the lamp is incandescent rather than LED, get a diode rated 3 or 4 times the running current of the lamp.
[/quote]

Chris, they are just a plain single filament, automotive bulb that plugs into the 4 pin flat trailer connector that will light up either when you hit the brakes or turn on the right blinker. No other components inside and the plug only has the 2 wires.

I was gonna pick up a replacement end with all 4 wires and connect 3 signal wires to positive side of bulb connector. Well as long as I can find a way to restrict current direction anyway.

Because the bulb would be tapped into the left and right side blinkers when one is on it would back feed the other causing it to blink like if you had your 4 ways on.

I though of relays initially, but seemed like overkill.

Thanks.](Diode logic - Wikipedia)