TYM 723 drive issues

[bigAranch]

I was brush hogging and suddenly the tractor's "f" indicator light went dim.When i put in forward or reverse the "f or r" light on dash gets dim once machine moves. It no longer moves right away there is a delay then the light dims. Any thought would be greatly appreciated. The delay is about 4 to 5 seconds. Also machine will not move at all if I engage 4wheel.