Push button switch wiring help

[CChase]

I am looking for some help wiring up a push button switch for supplemental back up lights. I am trying to figure out how to have a momentary contact push button switch that would turn the supplemental reverse floodlights on when tapped while the truck is in reverse, then when it's shifted out of reverse (i. e. , the standard backup lights are no longer getting power), the switch would "reset" and the next time the truck is put in reverse, if I wanted the lights to come on again I would have to tap the button again.

I have racked my brain about how this could be done with relays and can't conceptualize how that could work, then got to thinking maybe there is a switch that is made to do this but after searching hardware stores, Radio Shack, and Digikey I can't seem to find any way to accomplish this.

Can anybody help with how this could be made to work or point me in the direction of a resource that might tell me how to do this?

 

[DavidC]

buy a 2 pole relay, tap a wire from your existing backup lights to the common on one pole of the relay. From the N. O. side of the contact wire to the relay coil,this will be the relay hold circuit as long as you are in reverse. For the momentary switch, one side to 12vdc from the other side to the relay coil also. this will activate the relay and the holding will keep it energized. The other set of contacts can be used to power the new lights.



Dave

 

[Allnew2Me]

A locking relay is the answer to your situation. If I could figure out how to draw a schematic on here it would be easier but here is how I would do it.

Wire your momentary push-button switch to activate the coil of a DPST relay. The power source for this relay coil will be the reverse light circuit. So the coil will only recieve power when the stock reverse lights are on with the shift lever position, and the button is pushed. The switch needs to be wired in series from the reverse source to the relay. Here is where it gets tricky. On the DPDT relay you have what are essentially two switches in one. You need to wire it so that the second set of contacts supplies power to the coil so that it locks itself on when you push the button. This power source has to come from the reverse light circuit on the truck, but before the push-button switch so that it is hot as long as the truck is in reverse.



Now wire the auxiliary backup lights so that they are powered by the relay's first set of contacts. Pay attention to wire size and fuse the supply at the battery.

When you put the truck in reverse the power from the reverse lights goes to the switch but no further until you push it, and when you do that the relay closes the first set of contacts that turn on the auxiliary lights and also supplies power through the second set of contacts to the coil of the relay holding it on even whem you release the push-button because the power is now coming directly from the reverse circuit on the truck. As soon as you take the truck out of reverse the power to the coil will be cut, turning off the backup lights and the power to the coil.

 

[DavidC]

Both of these systems are basically the same.

The differences are

system1, push button can be pressed at anytime to activate lights. Sometimes comes in handy with a vehicle behind you with bright lights on:-laf.

Lights will not stay on unless in reverse.



System 2, lights cannot be activated unless in reverse.



These are pretty much the only two choices you have for what you want.



Dave

 

[CChase]

Thanks guys! That is exactly what I was looking for. Both of those make sense to me, now I just have to figure out if I want to be able to "thank" those who drive with their high beams on behind me...


Thanks again!

 

[CharlieFoxtrot]

Just in time! I was trying to sort out this same thing. Here's a thought - the "system 1" method would be handy if you wanted to have the lights on while the truck is in park and you're back there messing with something. For me, it's a no-brainer.



What are we using for aux backup lights? I have cheapo fog lights and they cut off so sharply, they really don't help my rearward vision like I'd hoped. Are trapezoidal or flood "tractor lights" the next thing to try?



thanks!!

kevin

 

[Allnew2Me]

I'm using these.



https://www.turbodieselregister.com...scussions/173498-let-there-light-reverse.html

 

[DieselDoghouse]

Another option: a circuit similar to the logic chip for our heated mirrors (they reset when key off). A relay would control the lights, the relay is controlled by this circuit (I used similar to control windshield washer heater), but is only powered when reverse light buss is live. With this you could push on/push off or push on/resets to off when out of reverse. It would require the relay and this circuit. I believe it uses a timer/op amp IC chip (ala radioshack or other). I have the schematic I designed in file butbwe muster moved so... It's packed but I can search for it. If memory serves it's a Signetics LM556 hybrid chip-cheap and accessible. You can pm me anyone wants the info.