Rear Tail Light And Brake Light Out

Hello Everyone,

Dealing with some electrical issues in my rear tail light. Initially the tail light went out intermittently. I replaced the bulb and it went out again. When I inspected the circuit board with the light sockets it had a slight burn so I replaced it as well. Still no turn signal and the brake light is gone as well now. When I turn on the flashers rear tail light is still out. All other turn signals work fine. When turned on the night time driving lights the reverse light seems to be on now as well for both sides . All fuses tested good and no other issues. The left and 3rd brake light work fine as of now. Does anyone think this could be something other than the multi function turn signal switch? I saw some other posts about the towing light pig tail but when I checked underneath it is not present. I have a towing hitch but I have never used it and seems I do not have the adapter there.

Also I just found out my hi beams do not work as well.

Have you checked the voltage within the socket of one of those lights are are not working? When the light switch is turned on, you should have 12 volts on one of the socket's pins. Also, you should have a direct path to ground on another one of those pins, as this could be a ground path issue.

I'm guessing you have a 91-99 Tahoe.
I would use a test light or voltmeter and check for both power and ground at the taillight and the headlamp. The 2 should not in any way be related, but I've seen stranger things.

Sorry yes it is a 98 GMC Yukon. I will test and report back.

No power to the bulbs that are out.

Alright so I focused on the tail light first. With that issue it was a dirty connector and once I cleaned it out it is functioning normally. My hi beams are still not working on each side though. When I activate the hi beams the low beams stay on.

On these trucks the low beams are made to go off when the high beams are on if it's never been modified. Does the high beam indicator on the dash come on? Sounds like the dimmer switch might be the problem.
First check ground and power at the headlamp connectors and back trace from there. On all of my trucks I modify them so the low beams stay on with the high beams by adding a relay.

No the high beam light does not turn on and the low beams do not turn off they stay lit. No modifications on this one.