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I have replaced the hand controls and headlamp, and am now trying to wire in a switch to control all of the lights. I have a basic 15A ON/OFF/ON switch, and am trying to have the headlight, running light and front brake light switch all be controlled by this one switch. Basically I want ALL lights off in the OFF position, but in either ON position, the low or high beam on with the running light and brake light(if activated). So I need to split both wires on the ON sides into 3 wires, and to prevent current from flowing to both high and low beam simultaneously, diodes are necessary. This leads me to my question:

What kind of Diodes would you say are best for this application? Obviously they need to be 15A 12V, but I'm newer to electronics and diodes and google searches didn't help me understand.

I found these diodes on Amazon, they say 15A and "Maximum DC Blocking of 45V", which I would guess would work for 12V. Will these work?

https://www.amazon.com/Akak-Quality...UTF8&qid=1501100882&sr=8-2&keywords=12v+diode

Below I have done a crude sketch of what I am trying to accomplish. 2 things to note about the drawing: The power input on the switch is not on the side, it is in between the two outputs like most of these type switches, I drew it to the side so wires wouldn't cross. Also the two power feeds for the front brake light will combine to one wire, I didn't show this because I didn't want crossing wires.

Thanks

Purple Violet Light Finger Hand
 

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It doesn't have to be that complicated, just use a six pole double throw switch. Its basically two three pole switches in a common housing. Wire one side for high/low beam and the other side for the rest. I would suggest you wire the feed for the brake light switch so that it is hot whenever the ignition is on, you still need operating brake lights in the daytime.
 

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Now we're in my comfort zone, sort of.
First, I'm with Mike on the brake light. I recommend leaving it hot wired ALL the time.
Second, Those diodes should be fine, although the 45V reverse (blocking voltage) is a bit low for a vehicle power system. If you do decide to use diodes, you only need one diode on each side of the switch, no matter what all is connected to that side. Something like this...

--------------------------- Input 12V -----------------------------|____ |------------------------------------------------------------------------high beam
| |---|---------|>|--------|------ everything else----------------
O-----| | |
| |---|--------|>|---------|
|___| |_________________________________________low beam
In words, one side of the switch connects directly to high beam and to a single diode. The other side connects to low beam and a single diode. The other ends of the two diodes connect together and then to everything else you want switched. They symbols I used ( ---|>|---- ) for the diodes are pretty close to the standard electronics symbol. For the diode itself, the arrow points toward the band marked around the diode. In other words, the band end of the diode body will connect to the lights and the non-band end to the switch.

Third, the diodes will need to have some sort of heat sink. That may be as simple as mounting them tight to a part of the frame, or you may need to have a piece of aluminum sheet maybe 2 x 2 inches and 1/16 or 1/8 inch thick. At full power, they will turn about 7.5 Watts of power into heat. Some soldering irons are only ten watts. Heat is the enemy of electronic components.

If anything isn't clear, just ask.
Hope this helps.
Will

EDIT: I see my original drawing didn't turn out well. Let's try this:
Switch
| |----------------------------------------- high beam
|---|------|>|----------|------------------------------------------everything else
| |
|---|---|>|-----------|
| |------------------------------------------low beam
 

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Text drawings always work so well, don't they? As Mike implied, what you want is a DPDT 3-position (on/off/on) switch: https://terrylove.com/forums/index.php?attachments/dpdt_switches-jpg.19947/
Connect the power to the center terminals. Connect the running/brake lights to an upper corner and lower corner, on the same side. Connect the high beam to one of the other corners, and the low beam to the remaining corner. No diodes needed.
 

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FWIW, I agree that the proper switch is the better way to go.
 
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