GMC Repair: Running Tail Lights, gmc sonoma, gmc dealer

Question
I just wanted to say thank you very much Pete for answering my questions.  The lights and blinkers are up and running, and it was all due to a broken wire underneath the truck.  Just wanted to show my appreciation!!  Thanks! -------------------------
Followup To
Question -
Thank you very much Pete!  I had contacted a GMC Dealer in my area and they told me to check the sockets and their lenses.  I will be sure to check the black wires also.  Are there many of them?  Or will I know them as soon as I look under the truck?  And thank you for the compliment.  I like my name also!!  :)  Thank you for your time and advice...I am hoping we can get this worked out on my own, so I don't have to pay a fortune for electrical service.  Thanks again!-------------------------
Followup To
Question -
Hello!  We have a 1991 GMC Sonoma extended cab.  When we turn the lights on, the running tail lights will not work.  The headlights, blinkers, brake lights, and hazards all work fine.  But if you let your foot off of the brake the lights go right off.  We have changed the bulbs and my husband even tested the wires with an electrical tester to make sure there was juice going through.  We have no other idea what it could be.  It's a real pain driving to and from work in the dark with the hazards on so everyone can see me.  Please help a girl out?!!  Thank you!
Answer -
hello angel
look under the truck you will see some black wires this is ground you have a broken one and also check the sockets it could be bad on both . we will work toghter on this . good luck to u hun and you have a pretty name pete pleas rate me my service
Answer -
Hello
it will take a littile time to find it i am sure you will just take your time and go one wire at a time it is nerv racking . i am in the shop of mine 12 hours a day . i could tell u some things what i find. oh well if you need any more help u let me know hun and please rate me pete

Answer
Hello Angel
I am so glad you found the wire i know it is not easy but i had a  idiea this is what was it was if i cn help u at all again please feel free to ask . good luck to u hun again and i really do like your name take care need help let me know again and please rate my service pete