Vehicle: 78 4x4 Flareside bought new.
I have digital flashers installed for pulling trailer.
I used equalizer hitch for my 12' enclosed trailer(with 14 lites plus 2 tail lights)
I'm running the trailer lites off the trucks wiring.
I just bought 14 clearance lights(led) to replace the amp burners.
My problem being: My headlights go out after a couple hours pulling at night(less traffic).
Am I doing the right thing changing to led lights?
Or should I run power from the battery for my lights on the trailer?

My truck isn't anything special to anyone else but to me. It's never let me down. It may eat it's share of green(gas gussler) and I wish I had ordered an 8ft bed an maybe a 3/4 ton and a 351w. But I wouldn't trade her for any vehicle.
Just have an old 400(eldo4 barrel(it was eating gas anyway))4sp granny, dana ends,205 crusher. Even has a worn out seat(second one)

 

Pull the headlight switch out and check the plug very carefully. Over time, and with the extra load you have, the plug connectors get loose and create heat, which melts the plastic the plug is made out of. Then this only makes it worse. The LED lights will help, but you need to see how much damage is already done. If it's really burnt, you may need a new plug and a new switch. The switch has a circuit breaker made into it for the headlights. It works off heat, so that's what's making the lights go out and then come back on.

 

Shouldn't have to do all that. You could have several other things actually causing this proplem. One could be your alternator. Either it's got loose wires/connections, just going out or about to, or could be undersized for your load.
Not only the cheapest but a need to do anyway is to clean and retighten all of your battery cables. Pay close attention to getting them on both ends, at the starter and on the block. Also make sure there's at least one other ground from the engine to the firewall. Check the alt. wires for cleanliness and tighten them.
One last thing. If the alt. is working right and all cables are clean and tight I would check (all) light fixtures (sockets) for correct bulbs, moisture and ground.
Weird, I had a bulb get broke in such a way as to short my entire running light system on the trailer and truck in the dark no less. Got home the next day and saw were I had backed into something with back right trailer light, broke bulb and lense. Once I pulled the bulb, everything worked fine.
I have also had sockets with bad grounds but mostly water/moisture inside short them and still not blow the bulb. Everytime the particular bulb was energized it shorted and drew a lot more juice than it should have. It eventuall blew and I now have a purty blue and white glass bulb on display.
Easy to check, needs to be done anyway, and it eliminates all those areas.

 

He wasn't complaining of the engine quitting, or any other electrical problems, except the headlights. That is why I concentrated on the headlight switch.

 

I'm sorry if I misunderstood. In my experience, as short as it may be, lighting problems can usually be traced to something being dirty, rusted etc;