Headlights won't turn off.

[EGw]

When turning off my 1982 Avantii II the lights would not turn off.  The rocker switch for headlights and parking lights worked but the on/off rocker would not turn the lights off.  I am not sure the rocker is at fault.  The rocker seems to be working properly, it feels and sounds right.  Additionally, I suspect there is a parasitic electrical drain. When I got the car about a year ago it came with a marine deep cycle battery, which went dead shortly after I got it.  However, a full charge cured the dead battery issue until recently.  The car only has 15k miles, so has only been driven sporadically.  Long periods of not driving could have drained a regular car battery, hence a deep cycle battery? When I left it at friends while I was out of town for over a month, he said it went dead and had to be charged.  Could there be a short in the circuit controlled by the on/off rocker the makes the circuit closed?  Defective relay?  I love this car, but this breaks my heart.

Edited November 9, 2021 by EGw
duplicate word

[mfg]

On 11/8/2021 at 7:20 PM, EGw said:

When turning off my 1982 Avantii II the lights would not turn off.  The rocker switch for headlights and parking lights worked but the on/off rocker would not turn the lights off.  I am not sure the rocker is at fault.  The rocker seems to be working properly, it feels and sounds right.  Additionally, I suspect there is a parasitic electrical drain. When I got the car about a year ago it came with a marine deep cycle battery, which went dead shortly after I got it.  However, a full charge cured the dead battery issue until recently.  The car only has 15k miles, so has only been driven sporadically.  Long periods of not driving could have drained a regular car battery, hence a deep cycle battery? When I left it at friends while I was out of town for over a month, he said it went dead and had to be charged.  Could there be a short in the circuit controlled by the on/off rocker the makes the circuit closed?  Defective relay?  I love this car, but this breaks my heart.

You might want to drop the overhead switches and look things over.....Then you may want to swap the center (instrument) switches with the left (headlamp) switches to determine if the fault is in the headlight switch or not.

Edited November 10, 2021 by mfg
Typo

[Skip Lackie]

Most of us love those rocker switches, but they're not high quality. The on/off one could have failed.  If you have a multimeter, you can remove the switch and check to see it it's really turning off when in the off position.  A multimeter could also help you determine if you have a parasitic battery drain -- turn off/disconnect everything including the clock, disconnect one battery cable, connect the amp meter across the gap and see if there are any electrons crossing.

If you drive the car infrequently, you might want to invest in a Battery Tender or some other trickle charger, plus one of those cheap disconnect switches with a green knob.  In the long run, it's a lot cheaper and more convenient than dealing with dead batteries.