where can I find info on line about TIU revisions ?

Here you go. At the top of this forum. https://ogrforum.com/t...rials-andamp-manuals

Andy

Just to be sure, open the TIU up and check the nuts that hold the power posts onto the TIU. They come loose.

That is an old TIU.  Look at what Joe stated.  That is a real situation.

Any TIU after Rev G (original) has nuts to hold internal wires to posts. I recommend tightening the nuts carefully, then adding internal-tooth star washers and a second nut on each post.  In my Revs H & L, I did find some nuts were looser than I deemed adequate.  They are metric, and I don't have the size right at hand.  I bought some at Ace Hardware.