Truck shuts down when I turn on my lights switch

I have a 1995 freightliner fld120 with a DDs60 and no matter if I’m driving or if I’m sitting still the truck will emergency shutdown when I turn on my lights. Barely started happening Monday and I took a week off before that. Both the check engine and emergency shutdown lights cmon on. When I drive all day without the lights on it runs perfectly fine but a minute or so after I turn the lights on it shuts down. I have no clue if this is simple or serious.

 

No the truck sat for a week while I was at home.

 

Where would I take it to get the codes scanned? The dealer? I don’t have a scan tool

 

I got the above pictures looking at the trucks relays and stuff and a bolt was broken securing a line coming from the batteries. Could that be it? And what’s the pats name that holds all those cables together?

 

Yea I’m trying to get home this weekend to fix this I’ll see if it’s the problem . Thank you guys.