1990 Chrysler Le Baron how to reset computer.

IZZYRAE216

MEMBER
1990 CHRYSLER LE BARON
6 CYL
FWD
AUTOMATIC
144,200 MILES

How do you reset the onboard computer?
I have replaced the alternator and the battery, and yet the battery is not charging, check engine light is on, battery dashboard gage goes low and eventually battery warning symbol flashes. Sometimes in the morning the car starts normally and no warning or check engine lights are on. Battery gage reads normal. At some point during driving, check engine light comes on, battery gage drops, and check battery symbol flashes. Soon afterwards, car dies. It works, and then it doesn't work. What's up with this? Could it be the onboard computer?

1 Reply

CARADIODOC

MECHANIC
33,741 POSTS

You're approaching this the hard way. No computer to reset. The most common cause of this is worn brushes in the alternator, but since you replaced it already, the next suspect is corroded pins in electrical connectors. The voltage regulator can cause this too but that is fairly uncommon. He lives in the Engine Computer.

When the problem acts up again, measure the voltages on the three wires on the back of the alternator. The large one that is bolted on must have full battery voltage all the time. One of the small wires must have full battery voltage when the engine is running. The other small wire should have less than battery voltage, but never 0 volts. Based on what you find, we can determine where to head next.

Caradiodoc