There was this show I used to watch as I kid that I really enjoyed. It was about three friends who solved mysteries. There were two guys and a girl. The main character (if I remember correctly) had blonde hair and wore a red buttoned shirt unbuttoned. Also, he had this super watch that could do all types of things. It would help them in every episode.
Sounds like the show Martin Mystery
The series re-imagines the comic books main characters (Martin Mystery and Diana Lombard) as 16-year-old step-siblings attending Torrington Academy, a high school in Sherbrooke, Quebec. They work for a covert organization referred to as "The Center", which covertly protects the people of Earth from supernatural threats. As a covert organization, their work must be kept secret and for this reason, anyone who comes too close to their missions will have their memories of the event erased. Despite the fact that they deal with the supernatural and such, not everyone who works for the organization is human. Billy (a small, green-skinned alien), is actually one of Martin's best friends. Java (a caveman from 200,000 years ago), works as a janitor at Diana and Martin's school. He also aids Martin and Diana on their missions for “The Center”. As far as "The Center" is concerned, Martin's vast knowledge of the supernatural and his remarkable intuition compensate for his poor personal hygiene and huge ego. Diana resents these flaws at times, as Martin often does not seem to understand the seriousness of his missions, but generally loves him like any sister.