Can an Accessory Relay Leak Voltage?

I recently installed auxiliary LED backup lights on my 99 TRD 4x4. I used a relay switched by the stock backup lights to trip the relay and send power to the aux. Backup lights. Power (#30 pole) to the relay is via a aux. fuse panel mounted to the firewall under the hood. When the new circuit is first energized the LEDs look normal. After about 30 minutes they begin to glow and after being left alone all night illuminate at about 50% brightness. Your thoughts are appreciated.

 

It’s hard to tell what the problem is that you are describing. So your lights come on when they are off? Yes in theory you can have a bad relay that is making a connection when it should be braking. It’s my experience they fail open due to dirty contacts. There are solid state relays that bleed current. Relays are cheep, any way just to swap it out?

 

Swapped out the relay and problem solved!