I have a 1994 chevy 2500 4x4 automatic.
I power on the key and the odometer rolls and the speedo tack starts moving.
I turn it over and it won't fire up,I am getting gas to the carb though.
When the battery is charged it turns great but when it gets weak it starts clicking as it turns over,but it still turns over strong.

 

I changed the altinator and still the same,also the interior light and horn stay on and the battery is drained.