Charging system and dash lights

AZLYNP

MEMBER
2002 LINCOLN NAVIGATOR
4WD
AUTOMATIC
350,000 MILES

First I had trouble accelerating to 60 mph, it was okay at 55, but would shift or something at 60. After being parked a few hours it was okay, but the check charging system light starting coming on periodically. I thought battery or alternator. Then charging system, engine light, battery, ABS, advan trac lights all came on. I took it to mechanic and he checked battery and alternator. Both are good. Only engine light came on when he drove it. Drove to AutoZone to be checked on computer thing. Said 1 or 2 spark plugs need changed. That took engine light off. So what's wrong with the charging system? He didn't remove or mess with battery cables. Or anything else. They said don't worry about it. I'm worried.

1 Reply

BMDOUBLE

MECHANIC
1,139 POSTS

The regulator could be bad, which often times will show up as an intermittent issue. Also verify that the connections at the battery terminals are good, clean and tight, this gets missed even by pros! 9 times out of 10 a check battery light has nothing to do with the battery failure, but just a general low voltage issue or voltage regulator internal in the alternator has failed. And if you replace the alternator be cautious on which brand you choose! Get the best and most updated unit that you can afford, I've helped people that have replaced 7 or more cheap units before they threw in the towel and got a good one. Make sure that your charging system is putting out 14 volts and at least 100 amps, and check the basic connections first. I'll attach the wiring diagram so that you can verify that you're getting 12 volts at the power circuits.

Image (Click to make bigger)