The guage cluster backlights and the taillights went out. the battery also gets drained if I leave it for more than 12 hours or so. I checked the fuses and they were all good. I'm guessing a crossed wire or something. Any other ideas. Where should I look so it doesn't take me forever trying to follow wires? thanks for all the help in advance.

 

the dash lights and brakelights are on the same fuse- look at the back of the fuse box to see if there are any melted terminals. Your battery might need replacing. Voltage regulator may be sticking closed.

 

what do I need to do if there's a melted terminal? How do I fix that? My battery is a fairly new optima. The voltage regulator was an issue earlier. Where is the voltage regulator, I was having trouble finding it. I hate wiring/electronics!

 

MSA sells a factory replacement for $85 or an after market one that uses the newer blade type fuses. Neither of these will last if you don't find the cause. Get a can of contact cleaner from Radio Shack and clean all your harness connections one by one especialy ender the hood and the tailight plugs. There is a bunch of them to the right of the heater control and under the steering column. Be careful of the big white ones, they break easy. This made a huge difference in my '70. The voltage regulator is on the PS inner fender near the alternator. Since you don't like electical ****, you can take your car to a auto parts store that will check your system for free, Sears might still do it.

 

Thanks. I bought some time to pull the fuse box out today and all the connections behind it were fine. Nothing melt or burnt at all and all the connections were there. Which fuse is it that the tailights/dash lights are on? And what amperage is it. I dont have a datsun fuse cover. Thanks for the help.

 

I dug out an old fuse cover and this is what is on it-
Top left - Top right
Air cond - headlamp left
wipers - headlamp right
hazard flashers - park/tailights
horn - dome/dash lights
stop lights - common
Try checking your car in total darkness for any small lights staying on, glove box etc. If your lights don't work it could be from a bad ground in the rear harness.

 

Thanks for everything. Big help. I got the dash lights and tail lights working again. It was a fuse. It looks ok, but i guess it was messed up somehow. That fuse diagram wasn't the same as mine, but i just started going through all the fuses and i found it. Could the messed fuse be part of my problem for my charge loss? I haven't left my car for long enough to see lately if it's fixed or not.

 

i have been through this problem on 2 1972 240zs....
In both cases I found that the voltage regulators were bad when the battery was either overcharging or being drained...There are solid state regulators offered now that can help with reliability...
Personally...I upgraded to a 1996 300zxt alternator with internal regulation...I had to modify the wire harness at the regulator to make it work properly. I also had to change the pulley over to v-belt instead of the later serpentine belt drives.

As far as the park tail lights not working...I found that the melted fuse was caused by a short in the corner maker lights to the body....as these items age the bulb sockets can actually short out on the body and cook yer fuses and cause the entire parking light system to fail. get new rubber gaskets and check the bulb sockets carefully.

 

I installed a new ground to the blockand also a new fuse block on the fire wall by the Battery. I then ran all the wires thru that blco using 2 40amp fuses. this stopped the draining of my battery completely. I have had no other electrical issues since.

Sorry my crappy A$$ digital camera doesnt seem to want to take pictures.

 

As I recall.....there is only one wire that feeds the electrical system...It runs form the starter + terminal right through the AMP gauge to the fuse block... Late 240Z models are like 260Zs with the shunt and extra relays.
The extension lead that is actually attached to the starter terminal is the fusable link...many times these have been hacked by someone and replaced with regular wire..Can you say FIRE!!!!.
You probably had a dirt or acid induced short at the starter terminal and eliminated it with your nice fuse block....I assume you attached a lead directly to the battery + terminal to feed the fuseblock...

I had one that would do weird things if I got it wet.....turns out that when I rinsed the battery area I managed to deposit some acid/rust on the starter terminals....It malfunctioned in every way imaginable...I decided to replace the starter and cleaned up the area....everything cleared up after that.

 

Awesome. that info helps a lot. I'll probably end up testing my voltage regulator and then replacing as needed and then if I have to go through my wiring narrowing it down the fuse pull method (where you pull fuses until the battery drainage goes away and then you have found your circuit where the problem is....VERY tedious!)