HELP! Upgraded alternator in my '75 280z but headlights now won't work.

[nissanthanh 0]

No offense taken. I've got the meter handy and I can't wait to go home.... except I don't know exactly what I'm going to test yet and what readings I should be looking for. I'm assuming I'm looking to put one lead to the battery positive(with multimeter in 20v position) and one to the ends of those wires that are out?

Disclaimer: this is my first vehicle that I'm doing significant work on, so bear with me =)

In any case, I do believe the green fuse-able link for the headlight blew. I squeezed it and it's hollow feeling. As opposed to the other one is solid.

@Siteunseen: I think the other fuse-able link block is under the visible one. If you notice in the last photo, there's that silver box that's under it.

I'll get something to clean the wires with.

[Zed Head 2,203]

Once you get used to using a meter you'll feel exposed without it. It's a good feeling to get the proper reading on a circuit and it's a good feeling to get the wrong reading, before you connect things and cause damage.

On the fusible links, I think that 1975 only had one set of two links, and that's probably why the headlights don't work. The fusible link blew from a separate short, probably while working on the regulator plug, and took the headlight circuit with it. Another set of two links were added in 1976, most likely to avoid this issue. The fusible links came with a white plastic cover from the factory. Yours is missing.

You'll be able to check the links with the meter also.

[EuroDat 542]

Maybe Im not looking at it right, but are you splicing wires with AC relay connector? Thats the small three wire connector with 1 blue, 1 Blue with white stripe and one yellow wire. Your AC relay has one wire going into it. Maybe just something with the models 75 versus 78.

Im cleaning all my connectors in the engine bay at the moment, new self made rubber cups etc and now Im buzy with those exact parts. Here are some photo's of the system in my 280Z 77 model, all be it some what disnmantled atm.

The big black box (left in photo 1087) is the voltage regulator. The AC compressor relay is the yellow zinc coloured relay to the right.

Im probably not helping, but just interested in the differences between the two models.

Chas

Edited March 11, 2014 by EuroDat

[nissanthanh 0]

You are correct, eurodat. I'm not splicing it, I just panicked when I couldn't find the green-red and I unplugged those to try it out and now I dont remember the order:disappoin:disappoin

So, now that I have a meter, i put one lead to the battery and the other to...?

[EuroDat 542]

Thanks SteveJ. Yeah I was bouncing and confused at the moment. Thanks for clearing that up.

Tried this morning to look for more connectors. Only found 1 4pin that was going to the fuel fume thing(last photo). Hopefully help you guys see what I'm seeing.

[ATTACH=CONFIG]70168[/ATTACH]

Driver's side wires. Hanging green wire

[ATTACH=CONFIG]70169[/ATTACH]

Driver's side connector that isn't plugging into anything. Black/white and green/red (could this be it?!?! why is it hanging over here...)

The connector on the drivers side is for the washer bottle pump. I also took a photo of the back side of the AC relay connector. The blue/white strip is next to the yellow and blue in underneath. Might help you with locating the wires and refitting them.

Unfortunatly our models are a couple of years apart and they differ too much for me to help. Im afraid you will have to study the wiring diagragm and trace it step by step.

Chas

[siteunseen 3,448 5 Vehicles]

Well I learned something today thanks to ZedHead and google.com/images. :classic:

[nissanthanh 0]

[SteveJ 1,194]

I am curious. How long have you owned this car? Have you seen any instances of a previous owner re-wiring or altering the wiring in the car?

[nissanthanh 0]

Had her for a month. I've never seen a previous owner rewire. Worst comes to worse, I'll just put the original alternator back n re plug everything. But until then I'll wait for socal s130 to reply since he has same exact yr and issue.

I was looking up and down the harness to see where it probably could be. But no luck. Hmm.

[nissanthanh 0]

Btw I couldn't find a 4 plug color scheme. Closest was the 6 plug with what you mentioned on the firewall in the picture earlier this morning

[Zs-ondabrain 40]

I'll be honest with ya, I haven't read all the posts and don't know what's been written so far. and with what you PM'd me, here's my guess(s)

Check the fusible links, replace if needed and ACTUALLY test them. Make sure there's power to and from.

You should have power at the white/red wire on the headlight switch and power going out (when the headlights are turned on) at the red wire.

Double check ALL your grounds (below the battery, negative post to the firewall, ground on the alternator and most importantly, check the ground wire that goes Under the steering column from the headlight switch to the Turn signal switch. Squeeze the barrel of the bullet connector for a tight fit.

Use a meter to make sure you have a good ground in the center pin on the white switch on the turn signal switch (Your Hi/Lo beam switch) And make sure you're getting ground to the outer wires with each click of the hi lo switch.

Headlight wires are as follows.....

Red/white is High Beam

Red/black is Low beam

Solid Red is the right headlight power

Red/Yellow is the left headlight power

Those colors are consistent from the connector at the turn signal switch, the fusebox splits the power wire and fuses both left and right headlight and those colors are the same all the way to the headlights.

So check all your connections and make sure you didn't unplug the ground or any of the power wires at the switch, on the passenger side kick and in the engine bay. That's the best I can do for ya without any other info or reading 4 pages of opinions.

Dave

[SteveJ 1,194]

Heck, Dave. I wasn't going to give him any suggestions on the headlights until he sorted out his charging system.

[Zs-ondabrain 40]

Well, I figure it this way, kill of one problem at a time until there are no more. If he can find a simple solution to the headlights, that leaves only 1 issue remaining and easier to figure it out... But I totally understand where you're coming from SteveJ

[nissanthanh 0]

I will start with the alternator first, as it will at least let me drive to and from work without being stranded! =)

Thank you all for your suggestions btw. Like I said, worst comes to worse, I'll just slap the 50amp alternator back on and live with it. I'm thinking there's some work-around for the missing wire- just got to wait for those who've worked around it to reply.

EDIT: I did test the fuse-able links and power is going through both. And in the diagram that zedhead had post http://atlanticz.ca/zclub/techtips/fusiblelinks/index.html

the two fuse-able links are for ignition and alternator: not for headlights. See? I'm learning.... i think

Edited March 12, 2014 by nissanthanh

[SteveJ 1,194]

the two fuse-able links are for ignition and alternator: not for headlights. See? I'm learning.... i think

The path is not easy to trace, but the headlight circuit is protected by the black fusible link.

[nissanthanh 0]

Gave in and re-installed the 50amp oem alternator. And voila, everything works normally, even the headlights. Odd....