My neighbor bought a 1998 Dodge Intrepid ES from my other neighbor. Drivetrain is in excellent condition, but it does have electrical issues stemming from a clogged A/C drain that started draining into the car. (He knew this when he bought it from him.)

It suffers from random little electrical issues, mostly in the cabin. Seems like he'* worked on all of the other problems; today, it was the blower motor'* turn to be fixed. It used to run constantly on low speed, regardless of the switch. Then it died completely some time ago. However, tonight, we jumped it to the battery and it ran just fine.

Tomorrow, he and my roommate are going to start examining the wires and grounds. I've already suggested cleaning the ground busses and those atrocious battery cables. Any more advice?

Also, roughly where would the A/C drain be, and what would cause it to back up like that?

The a/c drain should be located on the firewall around the passenger side.

Just normal dirt build up is what usually causes a blockage.

If the inside of the car had any standing water in it I would pull all the seats and carpet. Take up every wire connection, clean it, and put dielectric grease on it.

And you need to be redundant about finding all. A bad circuit ground or a once wet/corroded junction can create heat that will affect/heat/blow other things in a harness.