I have a '71 240Z with the following problem.....
The driver's side headlight is dim--really dim. Passenger side is great. I have swapped headlights, tried grounding the headlight to the fender well, new headlights, and built from scratch a headlight harness with new connectors from the back of the headlight to the connector that goes into the main harness. No joy so far.
This started when I adjusted the headlights--they were fine. I turned off the lights, then turned them back on and the driver's side was dim. the headlight switch itself is going, as ig I turn it on "too far" none of the lights work. If it isn't centered quite right at the first click, the parking and tail lights don't work, either.
Would the headlight/wiper switch cause only 1 headlight to go dim?? What else can I try?? Am I missing something obvious??
Please help.
Ed "Out of ideas" in Wisconsin

 

The 280zx's had this problem frequently, so it's deffinately a possibility on the 240z.... check the headlight switch connection on the steering column, as there is a connector for the left, and one for the right.

 

In the past when this has happend it was a bad ground wire, I would look for a loose wire in that area.

Cethern

 

I have also had this problem on my '72. My fix was a simple one, albiet hard to diagnose at first. try this: the top two fuses on the right side of the fuse block, are your right and left headlight fuses. (yes, individual fuses for each light!), on my car, we "twisted" the fuses, and slid them back and forth a little in the "seat" of the retainer/fuse block. this remedied MY situation. perhaps not yours. I would try this before you rip any wiring apart.
sometimes, the connections at the fuses themselves,get slightly corroded, and lose the capicity to pass all the current nessecary to the task. this applies to the wiper and heat fan fuses as well.
Another note, worthy of passing on.: The wiring connections,..the push together connectors on our Z's are prone to corrosion....clean them up! you WILL notice an improvement. there are a couple, behind the passenger kick panel (in front of the door) and a couple more, behind the grill, near the bulkhead/rad support....clean 'em up...you'll be glad you did.
I hope this helps bud!

P.S. I LOVE my Z !!!