lost power, won't run or start, no horn , flashers, no dash gages. on 1990 Dodge Ram 50

What can I check? Lost power, won't run or start, no horn, flashers or dash gages. Truck started and ran fine. 2 weeks ago truck did this and then after sitting for several days it started. I did replace the key reminder switch as someone thought that was it. Wrong. Truck ran this morning, cut out one time just before I got to work. then started after work and ran for a few minutes then died on the road. Had to tow it home.

Asked by for the 1990 Dodge Ram 50
1 answer
Need to have alternator tested to see if is going out.