Lighting probs - '96 Signature

[anmh]

Random lighting anomalies: Headlights will sometimes come on during day when in Auto mode; gear position indicator light doesn't work most of time, but will occasionally come on. A/C control panel lights: different buttons will light up at different times. Compass will work great for a month, then be wrong for a week. Note: These changes NEVER occur while running....only when shut off and restarted. In other words: if a certain dashlight, compass, headlights come on when started, they will remain consistent while ignition stays on....whether it's 8 hours or 8 minutes. The dash has been out recently for a blend door servo replacement...I paid very close attention when re-attaching all cables.....no change whatsoever between before/after. Also: driver's door chime always sounds when door open, regardless off key in/out/on, or headlights on/off. I'm pretty handy with DIY repairs, and would like to avoid a costly garage diagnosis if possible.

[olopezm]

Hello and welcome to the forum!

Maybe you have a bad Light Control Module (LCM) it is located under the dash towards the center, or you could have an alternator diode leaking to ground, "Towncar" pointed me to this since I was having lighting problems.

Towncar:
Battery drain is common in this car when Alternator diodes leak to ground. Sometimes this condition also causes speedometer wander at idle, and definitely causes all sorts of electronic gremlins.

You should have it tested at an auto shop, I read somewhere that you could also use a voltmeter between the battery terminals and check for any AC voltage with the engine running, this should be an indicator of a leaking diode.

Best regards,

Oscar