Not quite sure what you are asking, but if you are changing the solenoid, then disconnect the battery first.
you have either a bad connection on your starter or battery .also your starter has failed or solenoid
You have a problem with the ignition in the steering columm, or there is a problem with the anti dieseler switch in the engine compartment. Depending the year of the automobile.
Love Battery was created in 1989.
the location of the battery is under the rear passenger seat
== == == ==
Sometimes an alternator with a weak diode(s)can test out fine, but can still trigger the light. I believe the problem is in your alternator. Good luck.
I have a 1989 535i and the battery is under the back seat.
get the CEL checked and fix the problem. Disconnecting the battery for 15 minutes will reset the light on an OBD1 vehicle.
I'm not a mechanic / technician but if your battery is overcharging or the headlights are too bright so people are flashing their headlights at you when you are just using low beams ( it sounds like a voltage regulator problem )
I had the same problem on my 1989 Isuzu Amigo XS 2.6, I replaced the Ignition Switch and everything was fixed and works like new now.
Disconnect the vehicles battery. Leave it unhooked for several hours. Reconnect the battery. This should reset the 1989 cougars computer.