98 legagacy. I had swapped LED's into the tail lamps and rear turns. These are 1157 size bulb (dual filament). I was wunning the parking lamp and the hazard during installation. I had poked some 1156 single filament bulbds in the tailgate lamps, and this makes the brake come on (voltage back feed)

 

Now i notice the marker lamps come on with the brake.

My 92 mazda does this (had not inspected)

 

Troubleshoot:

The bulbs are oriented correctly in their socket

There is a trailer harness and i disconnected that.

i had removed all the tail lamp bulbs and it still toes this.

I had not checked any fuses as this was later in the evening after dark.

 

I suspect: blown fuse; open ground.

 

The fron tmarkers illuminate more brigtly withthe lights on vs when coming on with the brake

 

 

If not mistakenly placed 1156 instead of 1157...

 

I bet that there is a short circuit between the two contacts,

 

inside the mere socket.

 

Kind Regards.

I am wondering this. I made sure the little washers were not left on the bulbs. The right side lamp, however, may have a short inside the socket or the wires are touching inside. I did swap out the right rear lamp housing, but kept the original pigtail to the car. I did notice, before installing the LED, that sometimes the lamp would go out when the wire was tugged on. I'll have to inspect or swap the pigtail.

 

I'll check the fuses, as i understand if a fuse is popped, one of the circuits will try to find ground thru the other circuit, as the lamp circuits share a common ground harness.