"wait to start"

O.K. guys,
I'm slowly working out the bugs in this "new to me" truck and have another question.....when I got the truck....the "wait to start" light would come on for about 4 er 5 seconds and go off...at that time, I would hit the key and the truck would start fine.....last week, it started rolling over more before it would start so I asked about injectors and glow plugs here.....yesterday, the "wait to start" light flashes on when you turn the key...stays on about 1 second....and goes out and the chimes beep faster like its ready to start.....I hit the starter and it rolls over about 10 seconds or so before it starts....and it started like it was on cold diesel....I dont think the glow plugs are heating......also, when the light goes out, there is a loud clicking noies under the hood that is repititous and the amp meter jumps up and down along with this clicking. Almost like something is kicking in and out! Any ideas here? Thanks for all the great info. here and the quick response to my questions......one thing at a time and we'll get this blue oval back to where she should be!