Lights turn off when engine is running???

[fjwagon]

What I should said was the ones I own, none of them had the grounds in said location and have 2 45s l, 2 40s and a LV.

 

[fjwagon]

I do not believe that is a correct statement. See P/N 90980-07003. Labeled as 82001 below.
View attachment 3448733

I meant say the ones I own. But I'm still not 100% if it was some added later. I seen them in fj60 and 62

 

[45Dougal]

Saw this diagram in another thread here (someone else trying to fix their alternator).

Interesting point is that the ground wire to the headlight appears to tap off from the alternator ground.

If this is the case, then this may explain your problem - your alternator is not correctly grounded. Either the plug is not making good contact, or its wired wrongly at the regulator.

 

[iliketomakestuff]

I just wanted to drop an update here. I was finally able to track down a replacement headlight switch for the 76 after buying 2 incorrect ones. I swapped the switch, and now the lights work as intended!!!
I'm perplexed as to how a switch would have a fault like that, especially after a disassemble and cleaning, but it did.
New (old) switch = all good