92 dodge diesel my wait to start light stays on all the time and my atlternater gauge show a discharge. any ideas to the problem ,runs fine and starts ok but drains the battery...

 

You should start by doing volt checks with a good DVOM to get the actual charging volts, and check your grounds and batt connections. make sure you check the body, frame and eng grounds. Next do a volt check on the int air heater (grid heater) to see if it is actually on or just current feedbacks in the indicator circut.