D_R

I've pulled every connection that I have come across just to check for any signs of a short or corrosion. So far everything looks good. If everything goes as planned tomorrow I should get the switch replaced. Hopefully that is the issue, either way I'll let you know.

OK got some time today, I'm not sure what I should be looking for my computer is down and it was impossible to read the wiring diagram on my phone. I took pictures of what I could see.

I had a long day today, will check that ground tomorrow and snap some pictures

The headlights do respond on auto, but that is still all that is responding. I'm going to check that side marker ground to see if that's the issue. Where exactly is the ground located, I have yet to find a decent repair manual for these cars so I've been kinda flying blind on these repairs

And I take it the sensor is that little clear lens just above my Vin plate?

Yes that's me, if it is indeed the daylight sensor how would I go about checking it out. I have searched for this and have found nothing regarding the first Gen LS. And please forgive me but would the light sensor effect the headlight switch in the on position and not just auto? I'm used to dealing with older cars with simpler electrical systems.

The only lights that do not operate are the parking lights that come on when the headlights are turned on ( side markers, tail lights). Last night I replaced the tail light harnesses and bulb failure box. Parts came from known working parts car. The parts look near new and they did not change a thing. Is there some ground or relay that I'm missing that only effects the parking lights? I've been reading that a faulty ECU could cause weird electrical issues, anyone know if the signal runs through it?

First off I want to say hi to the board. Just picked up my first lexus, it's a 93 ls400. Having some issues with getting the running lights to work. I've replaced the fuse and bulbs. I've inspected the bulb housings, the wire harness at the trunk hinge, and the bulb failure box. The switch operates the headlights and turn signals just fine. All brake lights illuminate when the pedal is pressed. Does anyone have any ideas on what I could be overlooking because I'm fairly stumped right now.