Why does the wait to start light come on then off really quick?

I have a 93 350 with a 7.3l jasper motor. Yesturday the positive cable from the starter to the battery came undone at the starter eyelid. Replaced cable then when I went to start the motor, I heard a clicking sound and the motor wouldn't start. The wait to start light illuminated real fast and then shut off really quick; less then a second. Waited a minute and then it worked properly (with no clicking and the light stayed on correct timeing). Three hours later tried to start tuck again and clicking noise was back and 1 quick flash of the light. The clicking was coming from the slynoid that is mounted on the back of the motor behind the carb. Replaced slynoid. No clicking now but wait to start light still 1 quick flash. I know usually it means glo plugs are burnt but it worked 3 hours ago for a minute and now nothing. Any other suguesstions other then glo plugs? I am going to check them and the harness for the w.t.s indicator. Thanks for any help.