Hello everyone, just bought a 94 LS400 last week & it developed an interesting problem. I've been searching but couldnt find a similar issue (unless I was using the wrong keywords to search) so thought I'd post up.
The drivers side headlight is about half as bright as the passenger side, taillights still worked perfectly. Then the tails died, and both headlights, but the high beams would light up when flashed, and fogs still worked normally. I thought either the battery was bad or alternator was going out. Went out this morning & before starting the battery was 12.2v - started the engine & went to 14.3v - turned on the headlights & they are now working again, tils are too, but the drivers headlight is still half bright as the pass side. All the fuses are good, dont know what to look for next - suggestions?

EDIT: Dash lights working fine through the whole issue

 

may be the infamous trunk harness issue, search trunk harness and you'll see what im talking about,

 

Just figured out when the lights werent working it was set to AUTO on the switch, but that still doesnt explain why the pass side headlight is normal & drivers side is 50% if that... I'll search the trunk harness topics. Thanks

 

maybe it's a bad bulb? If not the infamous trunk harness...

 

I hava a spare bulb so I'll give that a shot. Yesterday we went to my father-inlaws to visit, he insists its a bad ground wire (50+ year electrician) so I'm going to check that out as well.

 

TRUNK WIRING HARNESS!!!
http://www.lexls.com/tutorials/lighting/bulbout.html