My 98 Grand Marquis voltage gauge started intermittently dropping and the lights would dim. I replaced the alternator and the 3 pin pigtail since it was cracking. I still have the same problem with the voltage intermittently dropping. I tested the battery, charged it overnight and even tried a new battery in it. The alternator is working sometimes, so I don't think there is an issue with the replacement. I saw a comment in another thread: "Turn on the ignition switch to the on but not run position do you see an icon on the instrument panel representing a battery, if you do not see this battery icon the alternator is not seeing power to allow it to charge." So after reading that, I looked at the dash with the key on and engine not started. There is no battery light. What causes this to happen? What should I be looking for? Thanks for any help.
Voltage on gauge drops intermittently. No battery light at startup on 1998 Mercury Grand Marquis
by oldfordguy in Albany, NY on June 01, 2013