Tail light problem

[96BlackBetty]

Ok guys when I hit my breaks the lights light up like usual but when i put the running light on or driving lights on and hit the brakes none of them light up. I check the ground seemed to be ok and so does the wiring. Any opinions or thoughts on what this could be. Thanks Shawn

[Frazier]

When did this happen?

[96BlackBetty]

Its happened ever sence Ive had the car. Bout a year ago. I just decided Id try to tackle it sence Im putting my new tail lights on today. WOOT WOOT!

[GETGONE]

It's a bad/broken ground somewhere. Check ALL the wires closely again.

[96BlackBetty]

Ground is what I was thinking to. But yeah Ill be lookin at it closely. Prolly just end up re wiring everything though to be on the safe side.

[MarkIV427]

When the taillights are ON, lighting up the brake lights is supposed to make the taillights go out, until you get off the brake pedal. Then the taillights come back on. Brake & taillights are 2 different circuits but share the same ground. Maybe corroded inside the bulb sockets.

Not sure what is going on in your case but am sure glad it's not my car.

Did you know that the Flint Public Library,Main Branch, has a MASSIVE collection of GM Factory-Authorized Service Manuals!8-O Not Chiltons or Motors. But GM Manuals just like Mr Goodwrench uses. Might be worth a trip to Flint to flip thru the Electrical Trouble shooting chapter.

[93formulalt1]

Check the ground in the socket itself, I had the same problem with my taillights on my Formy, fixed it a week ago by running a new ground wire to the inside of the socket and putting a bulb in. Bad socket FTL. The wires all read the right voltages leading to the socket, but the bulb grounds to the walls of the socket, and the socket was corroded so the ground connection was broken.

[b.lee]

what 93formulalt1 said.

[b.lee]

Ok guys when I hit my breaks the lights light up like usual but when i put the running light on or driving lights on and hit the brakes none of them light up. I check the ground seemed to be ok and so does the wiring. Any opinions or thoughts on what this could be. Thanks Shawn

Have you been driving it at night?
that'd be dangerous as hello.

[96BlackBetty]

Yeah its my daily driver. My third brake light lights up still bright as hello to lol

[93formulalt1]

I'm telling you, run a separate ground wire into the socket so it touches the side of the inside of the socket, stick a bulb in it, and be done with it. I GUARANTEE that's what's wrong with it.