Dash Light Problems

Bought a supercharged 5speed 1999 TRD, the dash lights were still the originals and half of them were burnt out. So I swapped them for some blue leds from super bright leds. When the truck is off, the driver door open, and my foot on the brakes; the dash light will light up and the headlight warning buzzer comes on. While I’m driving with the headlights/dash lights off and I push the brake, the dash lights come on. Has anyone else had a problem similar to this, if so how did you fix it?

 

The most common reason is missing or very bad connection from your stop light bulb to ground. Does it do the same when you turn on hazard lights? If yes then most likely the tail lamp ground wire is not contacting. If not, most likely the socket for your tail/stop light bulb is corroded.

 

Had this exact thing, check grounds in both tailights, specifically the connection from the harness to the lamp holder. basically, when you hit the brakes, current goes from stoplight to rear marker light (2 filaments in series) and energized your parking light circuit. This includes dash lights and beeper that tells you the lights are on with door open.

 

Exactly the same happened to me when I installed tail/stop LED bulb that by design is leaking current from Stop to Tail circuit and all my bulbs in Tail circuits are LED.

 

It does not do do the same with the hazards on. So your saying the socket for the brake lights are corroded and it needs to be cleaned?

 

This, or maybe black/white wire between the the socket and the plug is broken (marked by red arrow on the picture). Make sure you check both: left and right tail lamp.

I assume you don't have trailer adapter. Because if you have it, it has to go away. This $hit is source of all electrical problems.

 

I actually do have a trailer adapter and it is a rats nest of wires but i never had a problem until I swapped dash lights to LEDs

 

So it is possible that you always had the "current leak" problem, but you never seen it as the load from the dash bulbs (5W each) was big enough to drop the voltage on the tail circuit below the treshold for buzzer and other funny stuff. I can suspect that you have LED front markers or maybe you don't have them at all, right? because two 5W bulbs in the front markers can drain some "leak" to the ground.

As I mentioned I did not notice any "funny things" when I put "leaking" tail LED bulbs - the current leak was small enough to get the leak flow through dash lights to the ground. And even I changed all my dash to LED I still did not notice anything strange, but as soon as I swapped front markers from 5W incandescent to LED the whole hell broke loose. I scratched a bold spot on the top of my head thinking what the hell is going on.
My solution was to fix tail LED bulb to block the leak (I added diode to to it).

 

I do not have front marker light at all, I moved the blinkers up into that position after I wrecked my bumper

 

So this is what I got going on, there last the OEM male plug, plus another female and male plug. The two extra plugs ate for the trailer adapter and what not

 

You should have one more on the other side (right blinker). Just disconnect that thing (connect factory harness directly to the lamp) and see if it helps.

 

Figures it out, it had nothing to do with my trailer brake setup but I’m completely took that out of the situation anyway. Turns out when I deleted my front marker lights the ground I chose wasn’t good and both side came loose, so I rewired them to a good spot and now my issue is fixed. Thank you @RysiuM for your help, I wouldn’t have even thought of the front marker lights had you not mentioned them