It's not uploading my attachments.

 

First off I'm doing this all on my phone so I'm hoping everything is in the right order.

In the first picture you see the amber coloured plug that had broken in a bunch of pieces (that's all I could find left from when it broke) that plug is suppose to sit in the hole in the brake pedal. I couldn't find a replacement one so I put a screw with a washer in its place but a nut on the back to hold it in place (second picture).

Third picture is what the light should look life without anything in that hole (light should be on). The fourth is with the screw in place (light is off). Hope that helps to start.

If it is blowing fuses I would assume that there is a short some where in that system. The wiring diagram maybe a place to start looking.

 

First download a copy of the FSM from http://www.xenonzcar.com/s30/reference.html.
Go to the BE section of the manual. You will find detailed breakouts of the lighting circuits.

Make sure the brake pedal is pressing the plunger on the stop light switch. Disconnect both brake light harnesses at the back.

Go to the fusebox and make sure there is no fuse in the stop light circuit. Using a multimeter put on resistance, measure the resistance from the outer side of the fuse (whichever side is closest to the edge) to the chassis. Make sure you are touching an unpainted metal surface on the chassis. The resistance should be infinite. Keep measuring while someone is pushing on the brake pedal. The resistance should stay infinite.

If the first test result is zero or close to zero (like less than 10), the short is between the fuse box and brake pedal. If the result of the second test is zero or close to zero, the short is between the brake pedal and the stop lights.

If both test results are infinite (or maxed out), the problem is in one or both of your stop light harnesses.

If you have a short, I would suspect it is somewhere in the body harness.

You have a problem with the brake lights if you're blowing fuses.

 

FYI - I have had a lot of these same issues and have described my (still ongoing) journey in my "280z Electrical Issues" thread, which may be at least a bit helpful.

For one thing, we have very similar tail lights issues. I managed to get mine on by working with the headlight combination switch. They shut off again, but that seems to be one part a lot of people have trouble with on these cars. Obviously your fuse box is the first culprit, but if that doesn't work I would suggest having a look at the combination switch and see if anything looks, well, screwed up. It's easy to get at - just unhook the battery, take the cover off around the turn signal and headlight switches (5 screws) and remove the two switches (2 more screws).

I'd try that, and also while you're at it, liberally use some contact cleaner wherever you see that appears to need it. One solution to these electrical issues that's been suggested (though it didn't help in my case unfortunately) is to spray the cleaner around the base of the turn signal switch and work the switch around. There is a ground there that apparently can be an issue if the car has been sitting around.

Don't make my bonehead error by accidentally unplugging your ignition switch and then not being able to figure out why the car won't turn on.

PS - your fusible links are on the passenger side of the car, about halfway down the engine compartment, maybe a foot in front of the battery. There should be two square caps. Take those off and you will see two wires under each one. Mine looked fine when I did this check but I assume that if they're screwed up it should be pretty obvious visually.

 

PS - your fusible links are on the passenger side of the car, about halfway down the engine compartment, maybe a foot in front of the battery. There should be two square caps. Take those off and you will see two wires under each one. Mine looked fine when I did this check but I assume that if they're screwed up it should be pretty obvious visually.

I regards to the fusible links, what is the proper way to test them? I'm sure that sounds like a silly question, but I'm putting it out there for use new guys.

 

you test a fusible link just like any fuse. Check continuity with a vom. if you don't know what a vom is you shouldn't be doing anything electrical on your car. The fuses in that picture look really weird. like most of them have overheated at some point and warped the conductor. Fuses I have seen have the conductor strip straight not warped. And yes the stalk switch controls tail and running lights so likely a problem. Brake lights are a straight deal. check for power at the brake light switch. screw and washer fix will work fine to operate that switch cause most of mine wound up with that fix.

 

You'd think a blown fusable link would be fairly obvious, but not necessarily. You need to check them for continuity. Plus with a fusable link, the "blown" condition is not all you need to look for.

Far more common is oxidation (corrosion of the spades (connectors)). Disconnect them carefully from the block, check for continuity, clean and de-oxidize the connectors, then reinstall them if they test good.

 

Thank you all for the help and suggestions so far. I have checked the fusible link as described above (although this car has no caps over them) and I had continuity on all of them. So I guess that's a problem solved. Thank you for clarifying some of the fusible link stuff; I've never had occasion to work on an electrical system set up like this, and I appreciate the clarity.

Those fuses in my box do look atrocious, I have a feeling they've probably never been changed and I know this car sat in a storage unit in California for like twenty years or something crazy like that. I plan on replacing all of them, but that's not my immediate concern.

I'm definitely going to look at the combination switch next. Probably first thing in the morning and I'll let you know how it goes.

I'm kind of learning this stuff, especially electrical, as I go. I've done a fair share of electrical work on vehicles, but they were mostly military vehicles which are diesel, and just very differently put together. I am treading very carefully, hence all the questions.

 

Ah, another question, that's kind of getting back to my original topic, when the tail lights are on, should all four 'lamps' be lit? I don't know, because I never saw it before it was broken. Should all four lamps be lit for normal taillights (headlights on?) When the brake is pressed, are only the top lamps supposed to get brighter? I'm making this assumption based on the top lamps being dual filament and bottom ones being single, but that doesn't mean the last owner put the right bulbs in. From what I can tell of the FSM, there is supposed to be dual filament top and mono bottom though. As I said in previous post, I'm treading carefully, so, if possible, could somebody confirm this or tell me why I'm wrong?

 

No just the top ones (reference the picture I posted above) I know the angle isn't the greatest and it was about 112 and sun out that day but just the top ones.

 

Alright, so it seems that everything is working again, I think. I took the cover off the steering column this morning and the combination switch looks like it was installed yesterday, not even any dirt on it. However, suddenly everything seems to work. Two top rear lights turn on when the lights are turned on, when the brake switch isn't restrained both filaments light up and the two lower lights appear to be turn signals. Does that sound about right?

I hate it when I fix something and I don't know why it's fixed, tells me the problem is likely to come back because I probably just jarred something into connecting correctly. Uhhgg.

 

Awesome, while putting everything back together I noticed something about the bulbs I swapped out of the tail/brake lights early into this debacle. The old ones were different and upon further inspection I noticed that the inside of the passenger side socket was melted to ****. So now I need to replace that. It's currently fuctioning, so long as it doesn't hit any bumps. And this is Oregon, we have speed bumps everywhere, there's four in my apartments parking lot alone. So she's still deadlined, gah.

 

Could it possibly bad contacts in the combo switch or along the wiring?

 

Combo switch looks brand new, the connections aren't even showing a little bit of expected corrosion from being old, so I think it's been replaced fairly recently. That was why I pulled the steering column covers off, but I couldn't find anything to criticize under there. I went over all the wires and found nothing to complain about. I did swap out a ton of my fuses because, as mentioned earlier, they were all warped pretty bad, so maybe tail light fuse broke when it warped instead of burning through.

After talking to the girlfriend, we're going to find a connector that's similar and improvise a functional socket until we can find an affordable replacement for that small harness on the back of the tail light assembly. I haven't even found anywhere that stocks it (or can order it), so it could be awhile, luckily I'm pretty good at doing these kinds of improvisations and can make something safe and sane.

 

If your needing a tail light harness put a request in the parts wanted section.

 

That's the plan, I'm just waiting until payday when I can actually pay for it, lol.

 

Total side bar, out of curiosity why did the gf decide to buy a Z?

 

Her uncle bought it from a family friend, we went over to his place for a weekend last year. He's good with cars, and he bought the Z for his daughters first car but decided it was too much car. I wanted to hump the car a little because I'd just sold my '88 Celica GT4 with a later model JDM engine that I had put a lot of time into and loved very much. So, of course, my girlfriend's mother's husband bought it right then and there. Then they realized they didn't have the time to really do anything with it so they straight up gave it to my girlfriend.

Now, now I am its mechanic.

I'm getting a small inheritance "soon," and when I do I'm getting a MK3 Supra with turbo and targa. Was going to get a rough Z and skyline the drivetrain, but decided the electrical systems on these things are cruel and that keeping one on the road is enough work. (not to mention that I'm trying to restore hers, but would try to hot rod mine.) Plus, I miss boost.

I actually really love this car and am constantly amazed by some of the engineering that is just so wildly different than what you normally see in something from 78. I want to make this a car that's as close to stock as I can make it and, hey, still have the spare tire and can to inflate it, unfortunately the rubber strap to hold the can down broke as soon as I touched it.