what is the usual cause for a parasitic battery drain on a 1993 grand marquis
2 Answers
There isn't a "usual cause", any electronic component can cause one, any short to ground can be a parasitic drain. Look up a few how-to's on finding parasitic drains. Just FYI, constantly opening a door will keep one or more computer modules in an active state and drawing more current, so if doing a test with a meter you may want to take that into account, or pull a fuse for the door so when you keep it open to access an interior fuse box it's not causing anything to remain active while doing your test.
1 people found this helpful.
Trippmeister answered 6 years ago
Don't forget to test the alternator, sometimes the diodes go bad. Look for things like trunk light not going off. Radio.