Headlights come back on randomly....

[malmed]

I had done the 6hi mod to my truck a few years back... I used diodes, and also made my fog lights stay on anytime my truck was on. I loved it, and had no issues...

Recently, My bright lights would randomly come back on, after they timed out, when I shut my truck off.
I would wake up to a completely drained battery.

One night after this happened, I had gone to work, went to leave and had no headlights...
I pulled the relays, and when I stuck in the bright relay, they came on, so I drove it home....
(I had a few extras)
I also swapped out the switch on the dash.
(I had an extra)

Now, I decided my problem must be a diode had gone bad, and allowed electricty to flow the wrong way, and burned up a relay.... So I pulled all the diodes, took it back to "stock". Put new relays in the headlight lo and hi and fog light....

Same problem.
Still bright headlights randomly come on, if it times out, or if I manually shut the lights off... also if I push down on the bright relay, it come on....

So now, my bright relay is pulled, and I have no bright lights.
I also replaced a relay on the outside of the fuse box under the hood, just thinking maybe... nope.
I pulled the plastic 'surround' off the fuse box, popped the fusebox up and looked for loose wires, connections, and found none....

So, I am at a loss on what to try next...

 

[malmed]

link to the noise I hear when they come on.... in the first few seconds of the video, the rest is wasted time

 

[exp500]

Test the Brake Light switch.

 

[malmed]

Everything seems ok with the brake light switch... as far as, push pedal, lights come on just fine....

 

[MassHoe04]

Trace wires on the headlight harness. Look for any nicks or damaged wire along the way back to the inside of the truck and switch.
Maybe you are getting a monetary short that causes the lights to come on.

Areas of special attention would be locations where the wires pass through openings in sheet metal panels (radiator supports, firewall, etc.) or over metal (fenders, engine, frame, etc).where they might rub through the insulation.

You could have something periodically making contact and acting like the light switch is turned on...