Greetings! 1974 Series 3 88" (LH Drive) owner here.
I've got a brake light question regarding the right side light. When the headlights are off, the brake lights work as expected. However, when the headlights are on, the right brake light fails to light. The left works fine.
I replaced the lampholder since the original was pretty bunged up. Replaced the bulb since I bunged it up on removal. Things worked great!
Next day, back to the same operations, no right brake light when the headlights are on.
Since the brake lights work (w/o the headlights on), I'm getting power to the bulbs. What changes when the headlights come on?
I'm thinking ground, but why does it work at all? The left side works fine. What is different about the right? The turn signals work fine too, both with and without the headlights on. My wiring inspections show they share the same ground as the brake light. The ground is a ring terminal, bolted to the bodywork, under the access cover.
The truck has been painted. Am I not getting "enough" ground through the connection to fire the brake light when the headlights are on? Does that even make sense?
Thank you in advance!
Jeremy