brake light problem???

[seawatch35]

2000 yukon problem: 3rd brake light works but tail light brake lights dont when pedal is depressed. checked fuses and all good bouth under hood,and cab also checked bouth bulbs and good as well also checked sockets with a muti meeter and get no power to either sockets but do get power to the running light part of the socker just not the brake part can any one help befor i take her in to the dr. and we all know what that means $$$$$$ also checked brake switch at pedal and it is good as well also the cruse controll does not work and hasent worked for about a year but the brale lights have worked till recently . also my yukon modle has the elctronic gas pedal not sur if it makes a difrance??? can any one help ???please thank you

 

[Rivieraracing]

Be sure to check ALL of your fuses, not just the ones labeled for the brakes. I had a similiar problem a couple different times when hooking up my toyhauler to my truck and blowing fuses that were not directly related to the brake lights but all three times I would lose them. I think one was cruise control related, can't remember the rest but do check all of them to be sure.

 

[tspain]

Look under the right rear fender, where the a/c heater lines go into the body for the rear air, right infront of the rear bumper.

There should be a junction block that both tail lights plug into, check and see if you getting power there, and as rivieraracing said, check all the fuses, inside and underhood. There are alot of fuses for the lighting systems, and some of them do double duty so to speak.