What causes brake light to illuminate poorly.

Hello fellow members,

I’m hoping someone can offer some help or guidance with a brake light issue I’m having. When I press the brake pedal, the brake lights don’t come on if the running lights are on. However, if the running lights are off, the brake lights work perfectly.


I’ve checked the grounds, fuses, and even rewired a few bad-looking wires, but I’m still stumped.

Any feedback or suggestions would be greatly appreciated!


Thanks in advance!

 

i had bad corrosion at one of the taillight connectors. i bought a new taillight, but weird things were happening when I plugged it in, including dimming and brake lights not always working. I eventually traced it to a loose and corroded connector on the truck side. once the connector was de-pinned, i cleaned and tightened up the female spade connectors to fix the problem.

 

The bulb sockets might be crusty. You should spray some electronics cleaner into them.

 

Poor grounding. Check the connections.