Power actively drains when headlights are on 89 245

[KrendleStaven]

Hello all,

I’ve seen a few posts about this subject and not many have seen a solution and even fewer applied exactly to my symptoms. The issue began about a year ago, I’m not sure what caused it but I noticed it happened the first time after driving in heavy rain. More or less, with the headlights on (or really anything else that draws power) the voltage in the car will progressively go down until the lights dim to nothing and you lose everything in your cluster.

At this point I have replaced the battery, alternator (actual Bosch) and serpentine belts.

What else should I be doing or considering that I’m not?

I’m starting to think it’s some kind of wiring problem and I’m terrified.

[volvolugnut]

Have you or anyone else checked the voltage at the battery while running? Compare with and without load. A good charging system should maintain above 13.5 volts while running even with loads.
You might have a short somewhere in the lighting wiring that draws greater than normal power.
Report back with your test results and conditions of tests.
volvolugnut