The lights usually indicate a charging issue. If you have an amp meter you can check to see what the alternator is putting out at the battery, should be about 13-14 volts. You can also check the battery to see if you have been running off the alt or the battery. If the alternator isn't working the battery should be below 12volts.

If no amp meter, you can pull the alternator and have it checked for free at most parts stores. Be sure to disconnect the battery first, the alt cable that runs to the battery has power to it all the time.

More than tread lightly. Leave it like you were never there, nor anyone else.
'90 X-cab 4.88's 33 BFG AT's, rr ARB, Headers, Ignition upgrade, cold air induction.
'91 X-cab 5.29's 315's BFG MT's, rr ARB, custom bumper and flatbed