Calling Electrical Wizards! 3 Way Dome Light?

Hey guys. I'm wiring my rock lights into my dome light. The threads I found stated that power is pulled from the fusebox/battery, and the ground is pulled from the blue wire in the A-pillar. Right? Sounds easy enough to get them to come on with the dome light. The problem I've come across is also having it be able to come on WITH a switch under the Hvac. Do I need a 3 way switch? Is this even possible? Can someone describe this in Layman's terms please??

 

Keep in mind simple is always better. While things can be made to work, when diagnostic work is needed in the future, it will be more complex.

Why not just make the lights manually switched and not worry about the dome light option?

 

I know it can be done but to tell you how I would need the EWD for your truck

Do you plan on a relay ??

 

Having just a switch was my original idea, but then I saw guys that had it just to the dome, and really liked the idea of having the ground/steps light up when unlocking the doors at night. So i figured I'd try and get the best of both worlds.

I wasn't planning on using a relay since the led strips hardly pull any power. What part of the diagram do you need?

 

Cool idea!

 

Thanks! Hopefully I can get it worked out in here

 

It's possible, use a double pole double throw switch and you also need a diode. You need to figure out the total amperage for ALL lights (including the dome) and factor that in to your scenario, I would also limit the max amps to around 85% of the load.

 

So what you're saying is that the switch must be able to handle total amp draw without a relay?

 

A relay isn't necessary for this application IMO. I would think total load would be 5 amps or less .. LED lights don't draw a lot of power.

If you want to use a relay, then by all means do so. But to specifically answer your question - not necessarily. There are some accessories that would draw 30+ amps, I wouldn't put 30 amps in the cab myself, that's what the relay is for. With that being said, as long as you trust your wiring skills and the components you are using - you should wire it up the way you want.

 

Thanks!

 

Here are some wiring diagrams to search thru. Maybe one will work for you.
https://www.google.com/search?q=3+w...DbkZLNAhVVRlIKHQtGAXgQsAQIHA&biw=1281&bih=641

 

Thanks! Could you elaborate a little on the diode and double pole double throw please? I havent worked with those before...

 

Double pole double throw switch:

 

You'll need a similar switch (toggle, rocker, etc. just that it should be On-Off-On.)

 

Right on man thanks! If I have 2 grounds on the switch, where would I hook up the power I pull from the battery?

 

do note that the dome light in our truck is GROUND switched by the ecu (to create the soft on soft off effect) That is, its ALWAYS fed power, then the ecu slowly drops the negative side to zero volts to turn them on etc.

 

Really? I did not know that. I guess not everyone reads well. But I did say that the added Light Emitting Diodes strips need to be always hot, as in always "fed" power, as in not ignition power.
Battery to fuse to LED's to switch to grounds.
If the OP is using the engine bay fuse box, all fuses (except one) are constant hot. (ON). If he chooses inside fuse box, there are two hot ones there; lock circuit fuse, 12v power circuit fuse.
But, I suggest using a add-a-circuit to the dome fuse inside the engine bay fuse box. In case of issue down the line easy to verify or separate while diagnosis is underway.
Also for the blue dimming wire, I also suggest taping the wire at the connector, not the overhead or A-pillar. Keeps the added circuit below and less wire.

 

Awesome! I am also planning on doing the same thing, except with some running lights on my steps. On when domes are on, automatically on with parking lamps. One question I have is this - I was going to power a relay with the parking lamp wire and isolate that power from the dome ciruit using diodes. But the parking lamps flash when unlocking the doors - anyone think this might be an issue?

 

Parking lamps(tails)? You meant turn signals flash when locking and unlocking...right?

 

Yes, thank you! You are 100% correct. Just watched the signals flash as I locked/unlocked the doors, parking lamps only on when they're switched on. Looks like my theory is sound, now let's see if I set the truck on fire installing the running lights.