04 dodge ram 1500

3 wires. one would assume high beam, low beam and ground. in fact one is even black


*with the plug to the bulb detached... light switch on high beam off.
wire1 13v to black ground wire
wire2 13v to black ground wire

*with the plug to the bulb detached... Light switch on high beam ON.
wire1 13v to black ground wire
wire2 13v to black ground wire

??? why do both of these wires have voltage weather high beam is on or off? is the high beam switch a resistor, only allowing certain voltage across the ground wire, if that's the case wouldn't the voltage being detected across the wires change accordingly?

My first goal is to hook up my plow lights, it would be nice if i can use the high beam vs lo beam (plow lights have 4 wires so i assume can use high and low). it would be real nice if i could use a new set of lights and hookup the turn signals, but thats a different circuit and question.

for now, what is distinguishing high vs low if there is 13 v going to the wires all of the time?

oh, and i tried bridging each wire from the connector to the bulb connector with the volt meter and got no voltage no matter the high beam position ???

 

First, before anything else, please read this:
https://dodgeforum.com/forum/dodge-ra...s-section.html

I will move this to the 3rd gen section for ya.

 

Really, you should only use the headlight leads to trigger a relay if you are running additional lights.. In my sig truck, you'll see 2 light force lights on the grill guard (similar to your plow), they will only turn on when the high-beams are on. The high-beams provide a voltage 'signal' to a relay under the hood, to provide power directly from the battery. It'll be easier to trouble shoot, less amperage going through truck components that aren't designed for it, and easier to modify if you need to later. I have a switch inside the cab that allows me to select if they come on or not with my high-beams.. It makes it really nice when I'm going down the highway with them on, all I do is flick the lights to low-beams in case of an oncoming car/truck and my off-road lights go off too.

 

that does sound like a good way of doing it, not drawing more voltage through the high beam switch, which i might be having issues with. tho plow lights arnt that simple. your lights are basic on off lights, whereas plow lights have high and low beam lights. putting a relay on
the heqd light ground wire would work to simply throw the relay switch, but it wouldent defrinciate between the high and lowbeam circut in the bulb.

frankly im at a loss as to how controling the ground wire can change which circut in the bulb the electricity travels. its probably simple, but i dont design dc circuts so i dono how. it would have to be the resistance put on the ground wire. perhaps one filiment has a higher resistance, needing more amperage to get through, and once the resistance is lowered on the ground allowing more amps through the bulb giving tue needed juce for the other filiment and that draws all of that juce from the first filiment??? if this is the case i would have to know the values and have 2 separate relays of equilivent values to get low and high on the plow light, rather than always on high.

shrugs?

right now i just hooked everything up in parrellel. high beam wire to high beam, low to low and ground to ground. i did take a chance with this. but it seems to work. there is only one thing im worried about. perhaps you can tell me whats going on. it seems sometimes it will work perfectly, mainly if it has been used recently. all 4lights come on, all 4 high beams work. however sometimes they either wont come on, or moreso some of the lights will come on. seems to be random. if i play with them a little, on off, high on then off, they all come on and from there work perfectly.

ill play with them some more today and see if i can find some sort of pattern, although i caint think of anything to do other than check the connectors and making sure the battery is charged. really seems to only be the first time their turned on that there is issues. so i dono. i would prefer to have them work correctly all of the time, playing with them would be more of an annoyance than having them controled by the brights with an off on only functionality or even having a toggle in the dash.

i know if they sometimes dont come on my wife will turn them on at night and not notice if they hadent actually turned on.

 

I've got my off-road lights wired similarly but I wired the relay I installed to the fog light relay. I almost never use the fogs, so hitting the fog switch turns on both the fogs AND my pair of 130 watt lights. Again, just like Cthulhu, I'm only pulling about 1/3 of an amp off the fog relay to trigger the off-road light relay...

 

could that be my issues with it running sparaticly. pulling too many amps?

 

seems kinda consistant that at firat the lights do not work untill you hit the high beam switch

 

neighbor let me know their both live, with just no amprige untill low or high is chosen. when i had them hooked up in parrellel, which was a gamble, it did mess with the pcm a little bit, they didnt want to come on the first time switching it on, but after setting high or low beam, or changing to one rather, it started working well.

i am just hooking up some relays from the high and low beam wires and pulling juce straight from the battery.