Net-Viper X

Hello all,

I recently developed a problem with the circuit board in my Firebird speedometer that caused the odometer to randomly stop working, so I picked up a replacement gauge cluster to get the board out of it. When I got the thing taken apart however I found that the circuit board is different on mine. The replacement is a much smaller board with fewer parts on it. I added a pic below of the difference; my car is a 91 and has the longer board pictured on the right, the replacement is from a 89 and has a board like the one on the left. Can anyone tell me what the difference is? I tried it in my car and everything appears to be working but I am curious why the board on mine is bigger, what do those extra circuits do?

Thanks