headlights won't work

[Rust Bucket]

i've got a '72 240z and the headlights won't work.

i got the right one to work at one point, but only when the brights were on,

however, as soon as i turned on the car, the headlight wouldn't work anymore and i haven't been able to get it to work at all since then.

when i test the connector on the car, it gives me 12 volts of power, but when i plug in the connector going to the headlamp, the light doesn't work. i know for a fact that the wires going to the new headlamp are fine, so shouldn't the headlight work?

does anybody know what might be wrong?

another problem is that when i plug in the right headlight connector, the bright's indicator on the instrument panel won't light up..

any ideas?

[Zs-ondabrain]

So I made a trip out to matts house today and found out where he got the name Rust Bucket. Anyways, The wiring is shot and the switches need to be rebuilt (by me if he can't figure it out) we finally got 12 volts to the headlight plugs but barely 1 amp worth. Luckily, my upgrade harness only requires .250 amps to transfer power from the battery to the headlights.

Plugged in my relay harness, kicked on the combo switch and TAH-DAH!! lights galore. so now he has lights but the switches really need to be rebuilt.

Don't forget to keep the grounds clean and grounded well. That's the biggest problem with almost every 240Z that has electrical problems.

Was great to meet ya today Matt. Beleive it or not, I had fun fixing your Z and your chokes (whole nuther story) becasue fixing stuff is what makes me happy. Getting paid is number 2 on the list.

Now if I can get JonnyRock to come down on Sunday from Bellingham, I can fix another one and make it a full week of working on Z's.

Dave.

[sblake01]

Sounds like me except the only Datsuns I get to work on for the most part are mine. Along with changing the oil on all three Datsuns, i've spent that past week changing out the #6 coil on a Lincoln LS V6 (royal pita!), replacing the orifice tube and flushing/recharging the AC on the cleanest 86 Cadillac Eldorado you'll ever see (27K miles!), changning out the distributor on a 94 Cadillac Fleetwood (another pita, it's behind the water pump, etc.), and front and rear rotors/pads on a 2004 Toyota Hilander. Busy week. (Note to self: learn how to say no to friends, relatives, and neighbors)

[zanthus]

Stupid question time. Where do I check to see how many amps are going through my plugs. I've got a multi meter I just haven't figured it out yet and my headlights don't work. I have cleaned the combo switch however.

[Zs-ondabrain]

Stupid question time. Where do I check to see how many amps are going through my plugs. I've got a multi meter I just haven't figured it out yet and my headlights don't work. I have cleaned the combo switch however.

Unplug the parking light fuse, turn the headlights on (and nothing else) disconnect the battery, and put the test leads on the battery clamp and the battery terminal. (if your meter has Amp check capability) That should tell you what the headlights are trying to pull.

Another way is to pull the parking light fuse and one of the headlight fuses, test between the fuse clamps of the headlight fuse. the reason for pulling the parking light fuse is to keep the parking lights from giving you a false reading because you can't have the headlights on without the parking lights being on at the same time.

Clean all of the grounds that bolt to the body, clean the battery posts and terminals, pull the headlight plugs and try and clean all terminals with a small jewelers file and electrical spray. Coat everything with a light film of di-electric grease (bulb grease-available at the auto parts store) The grease will keep water and oxygen from getting between the contacts and causing corrosion.

Dave.

Sblake1... Note to self...learn to accept or take money from friends, relatives and neighbors.

[sblake01]

Sblake1... Note to self...learn to accept or take money from friends, relatives and neighbors.

I've learned that but that's the part that makes it hard to say no.

[bpilati]

Hey Dave, my harnesses are still working great! Got any other projects in mind....maybe a stereo harness upgrade?

[MEZZZ]

I've learned that but that's the part that makes it hard to say no.

note to sblake1 and/or Dave, how much would you take to come to Cincinnati and straighten out my car?

[dogma420]

since we're on the subject of grounds...where is the engine ground for a 72 240z? I've never seen an actual engine ground cable....where would the ground be....and has anyone improved on theirs?, in their Z's? Everyone have a good Thanksgiving!

[Zs-ondabrain]

About the only engine ground you'll find on a 72' 240Z is the ground lead coming off the alternator.

The negative cable from your battery should also be going to the top starter bolt. This is an old picture, I've updated the ground wires in my engine compartment. I now have 4 gauge wires going from the engines motor mount bolt to the cross member bolt, one from the starter bolt the the #6 exhaust port bolt, and a new one from the negative battery clamp to the (stock)firewall bolt location. And finally put another one from the starter bolt to the stock harness grounding location (across from the starter and below the battery.

In the second picture, you'll barely see a silver 4 ga wire between the motor mount and and strut bar. and you can barely make out the one that goes behind the head towards the rear exhaust bolt.

The more the better and the grounds to the head area will help reduce the electrolisis in the cooling system, which we all know destroys heads from the inside out.

[zanthus]

What about the engine grounds on the 280, anyone know where they are? Or is it the same as the 240?

[sblake01]

note to sblake1 and/or Dave, how much would you take to come to Cincinnati and straighten out my car?

I have the right of first refusal since Dave is closer.