Weird electrical issue...

[Eside]

I hope someone can point me in the right direction. I have no idea where to start.
I’ve got a ‘99 Yukon. Ok, so during the day when I don’t have my lights on, the green “headlight” icon is lit up on my IP, and when I press the brakes the brake lights come on...but so do my front running lights? When I turn my lights on, the green headlight icon goes out, my left turn signal doesn’t flash and my brake lights STAY on! At first, I didn’t realize all this was happening, I just thought my flasher was bad. I pulled it out and it looked pretty bad, so I put a new one in. Seemed to fix the turn signal issue, but that’s when I noticed all the other weird things. Any ideas? I’ve searched and read as much on the forum as I could but haven’t seen anything similar.

 

[HiHoeSilver]

I hope someone can point me in the right direction. I have no idea where to start.
I’ve got a ‘99 Yukon. Ok, so during the day when I don’t have my lights on, the green “headlight” icon is lit up on my IP, and when I press the brakes the brake lights come on...but so do my front running lights? When I turn my lights on, the green headlight icon goes out, my left turn signal doesn’t flash and my brake lights STAY on! At first, I didn’t realize all this was happening, I just thought my flasher was bad. I pulled it out and it looked pretty bad, so I put a new one in. Seemed to fix the turn signal issue, but that’s when I noticed all the other weird things. Any ideas? I’ve searched and read as much on the forum as I could but haven’t seen anything similar.

I'm a little confused by your description, but the green icon is your DRL indicator. Hence it is lit under normal daytime conditions and goes out when you turn on the low beams.

 

[Eside]

Oh, duh...that’s right. All the weirdness threw my perspective off. Ok, so forget about the DRL icon.

 

[dubyagee01]

Sounds like your adapter for trailer wiring is shorted

 

[TigerEyz3]

Based on my personal experience with something similar, I'd put my money on the combination switch needing to be replaced - it's the stalk that controls the wipers, turn signal, cruise, and also the hazards. Easy to purchase, but a bit involved to replace (can be certainly done, but you'll need to rent a steering wheel puller). I replaced mine several years ago and haven't had any problems since.