Electrical Trouble, 92 MGM

I just got a 92 Grand Marquis. During test drives, it started up fine four different times, and then I drove it to work that night. When I went to drive home, I needed to be jumped to start, and then the battery was only enough to run the engine, and not the headlights.

I replaced the battery, and the car has started fine a few times, but when I turn on the headlights, the electronic dashboard turns off. The radio and clock still work, but all the stuff on the dash turns off. However, if I turn on the high beams, the indicator light turns on. I think it may be alternator trouble, but I was wondering if anyone else had the same/a similar problem. Thanks.

Check out the battery cables. Fords can go weird if the voltage is wrong. If they're corroded, replace them. Had some of the same problems you're showing, veh ran fine then one day just quit entirely. Replaced the battery cables (positive was bad enough, looked like dust inside) and all was good again, all the "demons" went away.

Yep, I have a feeling I threw away a perfectly good Factory '87 100,000mi+ alterator (yes that much), and looked like an ass when the dealership found the problems to be associated with a heavily corroded Black ground cable, near the ground point.

I was soooooo embarrassed.