89' Trooper Electrical Probs

New to the forum. I have had this Trooper since new and it has been very good. My daughter has been driving it and since then it has aged significantly, new bumps and bruises. Anyway, last year it would start and run sometimes and then it would quit. Now some idiot lights are on, but dimmer. The blower works sometimes and sometimes not. If the idiot lights come on partially bright it might run for only 30 seconds and then stop. I tried a different computer to no avail. Must be electrical. Any thoughts?

sounds like a low voltage concern or poor ground maybe alternator get it checked out also check battry terminals