Headlights Stopped Working

[at-jefft]

Hey Everyone,

So yesterday I noticed that my headlights were not working(highs and lows). My side markers and turn signals still work though. BTW its a 260z

 

I pulled a headlight and used a test light to see if there was power going to headlight. All 3 wires in the connector had current(no ground?). This made me think that the bulbs were burnt out(I had left my lights on a week ago). I got a new one from vatozone and no luck.

 

So I am stumped. I have power to the bulb but no light? How can that be? Thanks, Jeff

Edited June 10, 2010 by at-jefft

[rossman]

Check your ground. There HAS to be a GOOD ground for them to function properly.

[at-jefft]

Where is that ground located?

[Zmanco]

On my 73 240Z the headlight switch is on the ground side of the headlight bulb. In other words, the headlight bulbs always see +12V on one of the three terminals, and when the switch is turned on, the path to ground is completed. So with the negative connector of your voltmeter connect to ground, you should be able to see +12V on 1 of the 3 headlight bulb pins at the connector. If you don't then check the fuse box to make sure the fuses are good and the contacts are clean. If you do see +12V, then check the resistance to ground of the other 2 connector with the switch in the "headlight on" position (switching between low and high beam should change which one connects to ground). If the resistance is much more than zero, the problem is either with the headlight combination switch or the low/high beam switch. It could also be with with the wiring, but the switches at nearly 40 years of age are the more likely culprits.

 

On my car the +12V wire is either Red (right side) or Red w/Yellow band (left side).

 

Hope that helps with your 260Z.

[Ajthib]

I would check the combination switch on the steering column. The contacts could be loose/corroded