Strange things happen!

I acualy have a Pontiac Lemans GSE, but theres not forum for it so here i am. The problem is with my signal lights. I can turn on my headlights and the front 2 signal lights come on and stay on. I can signal left and my left signal at back will flash but nothing at fron and same for the right. When i use the emergency signal lights just the back 2 flash and the front 2 do nothing. Any one know what the hell is going on lol. thanks
Jonny

If you dont get an answer here , you might also try posting this in the Pontiac nonspecific fourm

http://www.automotiveforums.com/vbulletin/forumdisplay.php?f=628

Have you recently changed bulbs or modified the wiring harness in any way?