Problem with back feeding 5 volts..

[72MARIO]

I am having a problem with my ls swapped truck. I have not.changed any of the cab or chassis wiring since the sway. The problem is the center 4 diodes in My brake and running glow slightly with the ignition power on. It's not a big deal untill I hook onto my dump trailer and the brake controller sees 5 volts and apply the brakes...

So far I have added extra grounds changed the headlight and. Ignition switch. No chamge5 Then I unplugged the steering coloum taillight harness light switch ignition switch removed all fuses and flashers and still have 5 volts.

The only way I can stop the back feeding is when I remove
the ignition relays from my BP Automotive harness.

Am I making a bigger deal out of.this than it is because I have led tails ? As soon as I add a 194 bulb in line on the brake wire the diados go out

[72MARIO]

Tail

[72MARIO]

Truck

[BR3W CITY]

Out of curiosity, does changing the ground on the tailights change anything? I have similar LED tails, and had to ground them to the frame instead of just the box/fenders. I've also noticed that I burned out a flasher sooner than I'd expect.

[72MARIO]

It was the brake controller lying to me supposedly I got one of the 200 P3 controllers that left the factory with the wrong program in it..there sending me a new one.

[72MARIO]

Originally Posted by BR3W CITY

Out of curiosity, does changing the ground on the tailights change anything? I have similar LED tails, and had to ground them to the frame instead of just the box/fenders. I've also noticed that I burned out a flasher sooner than I'd expect.

I added extra ground from the deck to the frame and ran a ground from the battery to the taillight ground. There was no change. I just have had enough of working on this truck.... so I went and bought regular Gates lights pushed them in and the cruise works now. Perfect.

I couldn't find a clean detailed way to add a load to the brake light wire and make the leds work. If I come across that I might put the leds back in.

[ls1nova71]

Originally Posted by 72MARIO

I couldn't find a clean detailed way to add a load to the brake light wire and make the leds work. If I come across that I might put the leds back in.

What year is your engine?

[franken]

Bad ground, not backfeeiding. Ground the needed. Drive.

[72MARIO]

2004 dbw I finally found the parts to make a cruise lever like the one I got from you.

[Hart_Rod]

Originally Posted by 72MARIO

I added extra ground from the deck to the frame and ran a ground from the battery to the taillight ground. There was no change. I just have had enough of working on this truck.... so I went and bought regular Gates lights pushed them in and the cruise works now. Perfect.

I couldn't find a clean detailed way to add a load to the brake light wire and make the leds work. If I come across that I might put the leds back in.

You can T into the white wire that goes to your brake light switch and run your resistor to ground.

[72MARIO]

What kind of resistor do I need to use ?

[ls1nova71]

I use a relay. Just hook up the coil side of one from the wire on the brake switch that is HOT when the brake lights are ON, to 85 on the relay, then hook the other side 86, to ground. I know that will make your cruise work.

[dayj1]

Originally Posted by 72MARIO

What kind of resistor do I need to use ?

1k Ohm is a common easy to find value that will work fine as a pull-down resistor in this application. In theory, it'll dissipate about 0.2 watts, so a 1/4 resistor should work, but I'd spend an extra 5 cents on a 1/2 watt resistor.

I generally use a resistor because it can be easily hidden, but Eric's suggestion of using a relay coil is perfectly fine and will work if that's easier for you to source.

[72MARIO]

Thank guys.

A relay is definitely easier to source and I have the bosch type bases with crimp on wire terminals so the wires can be continuous. I am not a fan of splices when it can be avoided.