i have a 91' chevrolet full size blazer (silverado) 4x4 and the speedometer doesnt work. although when it rains it seems to work for a while and then stops. hahaha i dont know i guess the speedometer likes the rain. but wanted to know if this is a speed sensor problem and where is it located?

thanx.

 

First try disconnecting and reconnecting the battery. I don't know why but sometimes that works.

The speed sensor is in the transmission, a small gear relays the speed at which the drive gears are turning and relays it to the speedometer. It could be that the gear is stuck. also there is another gear somewhere that can cause a problem.