Sounds to me like a brake switch, inexpensive part and easy to replace

I agree.

__________________
Master Computer Engineer, A+, Network+, MCP/MCSA/MCSE 4/2k/2k3 - Messaging, MCTS, MCITP, MCT, Brainbench, ICDL and starting Ph.D

380SE 1984 <------- Totaled by flipping accident
300SE 1988 <------- Sold
Volvo S70 2000 <---- 4 family
Opel Omega 2002 <-- 4 family
560SEC 1989 <------ Sold
560SEL 1990 <------ Sold
560SEL 1991 <------ 4 my mother
560SEL 1989 <------ Sold
600SEL 1992 <------ Current

http://search.ebay.com/_W0QQsassZkhazenzcc

Any thoughts on the used controler that I bought? Should it act just the same as the one in the car or is there something that needs to be done to it to get it to work.

I need to know because if there is something wrong with it I can return it, if it is ok and just needs to be programed or something it wouldn't seem right to return it because I needed a test part.

The left front sensor was replaced not that long ago because the speedo needle was jumping, that took care of that problem. And since he tested the rt front and said the signal was good why would the controler spit out a bad rt front sensor if it's the brake light switch?