Soundmasterg Posted March 11, 2008 Share Posted March 11, 2008 I'm trying to fix my non-working headlights and wanted to see if there are any common issues with the Z cars that I should look at first before I delve into it. The car is a '72 240Z that was sitting for 20 years and there were mice in the car. I do see that the wire for the antenna was chewed through a bit, even though it still works. I figure maybe some other wires are chewed up perhaps? I do have the proper voltage at the fuse panel.....anything else to check before I start to trace wires? Thanks! greg Quote Link to comment Share on other sites More sharing options...
bjhines Posted March 11, 2008 Share Posted March 11, 2008 It is late... but as I recall... 1. Headlight switch should feed the 2 headlight fuses power. 2. The power wires go from the fuse panel, out to the headlight "common" terminals. (LHL=RED/YELLOW wire) (RHL=RED wire) The low-beam terminals on both headlights are "T"ed together an run back to the high/low switch (lowbeam=RED/BLACK wire) The high-beam terminals on both headlights are "T"ed together and run back to the high/low switch (highbeam=RED/WHITE wire) The circuit runs from the main light switch, to the fuse panel, to the headlights, and back to the high/low switch, then to ground. Quote Link to comment Share on other sites More sharing options...
Soundmasterg Posted March 12, 2008 Author Share Posted March 12, 2008 Hey thanks a lot! Thats really helpful!! I hope to take a look at the wiring later this week and your advice will come in handy. Still will need to figure out the wipers and blinkers too.....I'm guessing a rat chewed the wiring offhand but we'll see. greg Quote Link to comment Share on other sites More sharing options...
Soundmasterg Posted March 18, 2008 Author Share Posted March 18, 2008 Your primer on how the headlight system works was very helpful. I also found something somewhere that had pictures and broke down how to take the switch apart and clean the oxidation inside it that crops up because of the circuit design, which I've attached to this post. The headlights work now. The thing I still need to figure out is why the marker lights aren't working. If you look at the switch and the wires on the top, The white/red is hot all the time. The red becomes hot when the headlight switch is turned on, and this makes the headlights work. The other side of the switch has a green/blue wire and a green/white wire. When the switch is off, the green/white wire is hot. If you move the switch to either of the on positions, the green/white goes to 0 volts, but if a jumper is placed over to the headlight side of the switch, then the marker lights will work and that will read 12 volts. I'm almost wondering if the middle contact which is where the green/blue is hooked to is grounding out through the board material or something and isn't supposed to. Does anyone have any idea how this is supposed to work, or why it isn't working correctly? For the wipers, I'll be doing the Honda motor mod as mine works very slowly with help. I fixed the blinkers by taking the blinker switch off and spraying contact cleaner inside and working it back and forth. Thanks, Greg Rebuild_240Z_combo_switch.pdf Quote Link to comment Share on other sites More sharing options...
Soundmasterg Posted March 19, 2008 Author Share Posted March 19, 2008 Just an update. The switch was working fine and the problem was in the connector coming out of the fuse block for the green/white wire. It was allowing only a partial voltage (about 8 volts) to the marker lights section of the switch instead of the full 12v and that wasn't enough to light up the lights. I wiggled the connector around coming out of the fuse block and it works now. Hopefully it doesn't stop working when I hit a bump! Greg Quote Link to comment Share on other sites More sharing options...
bjhines Posted March 20, 2008 Share Posted March 20, 2008 The fuse blocks have been the source of many problems. The fuse holder prongs are rivited to the tabs that the wires are connected to on the back of the fuse block. The brass rivets and contacts are easily loosened by previous owners improperly prying out the fuses. Once the fuse panel has been abused it will fail to work, work intermittantly, or it can overheat and burn the plastic parts and melt the cover. The best fix is to tighten up the rivets, clean the brass parts, and solder the contacts from the back. You need a high power soldering iron to do this quickly without melting any plastic. ... Quote Link to comment Share on other sites More sharing options...
Soundmasterg Posted March 20, 2008 Author Share Posted March 20, 2008 The marker lights failed last night again, so I decided to just get a new fuse block and I'm going with the new harness for the head lights and the marker lights. I don't have dash lights or interior lights at all even though the fuse reads ok and has the voltages in the correct place. That should solve the issues hopefully. If not, at least I'm starting with something that isn't 30+ years old that rats may have chewed up. Gotta do an alternator upgrade too as the alternator failed last night. I do amp work as a hobby so I've got soldering covered. Thanks though! Greg Quote Link to comment Share on other sites More sharing options...
bjhines Posted March 21, 2008 Share Posted March 21, 2008 That new fuse block from MSA is NICE!!! I just could not bring myself to spend that much money on something I could fix for free. I definitely like the MSA box though and I would consider it for a future project. Quote Link to comment Share on other sites More sharing options...
Soundmasterg Posted March 22, 2008 Author Share Posted March 22, 2008 Yah, I hear you. MSA has nice stuff but they're quite spendy on a lot of it. They could probably sell more if they would lower their pricing just a tad. The thing with my Z is that it was sitting under cover for 20 years and rats were chewing stuff in the car, so with all the electrical issues it is having, I want to start with a fresh fuse block so I can rule that out as a problem. I plan to do the headlight and parking light harnesses too. I have to do an alternator too, and have the 105 amp one on the way. It runs great though...only 83,000 original miles. If I get the electrical issues fixed and do the brake conversion and get some shocks on it, it should be good to go. Greg Quote Link to comment Share on other sites More sharing options...
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