Jim Grant's Tech Tips
Ford Crown Victoria, Battery Goes Dead
am at my wits end! I have had 2 Ford Crown Victorias, this recent one
drains the battery. Do you please know what could be the problem?? ...Pat
most common cause Iíve seen for a mystery battery drain on Fordís like
yours has been due to sticking relays. The relay for the vehicleís computer
is a great silent battery drain. This relay will keep the computer thinking
all night long until it runs the battery dead. Once the battery gives
out the relay opens, leaving not a clue to the cause for a dead battery.
The only way to catch this problem is to monitor current draw after the
vehicle has been shut off or pull the relay. I had one of those sweeties
torment me for over a month. The relay would only stick from time to time.
Of course it would never stick when it was at the shop. It would only
kill the battery once the customer drove the vehicle nose first into their
dark 40í barn that the wrecker couldnít back into. Each time the battery
went dead the car had to be pushed or winched out of the barn. The floors
in old barns always seem to slope in the wrong direction.