rajien2 Posted September 16, 2015 Share Posted September 16, 2015 (edited) 78 280z Hey guys, I have spent the last 2 weeks working on the engine swapped out injectors and ran new high pressure hoses.. She is running very well now. However I have some electrical issues before wiping out the multi meter and pulling ever single wire starting at the power source.... I just wanted to throw out what I am missing maybe its something super simple that someone has had before. Ive done some searching and heard issues with the dimmer switch, now is this what adjusts the dash lights or kicks the high and low beams on and off? Issues, No gauges but the speedo and volt meter work, everything else is bellow 0. No tail lights or blinkers of any kind, changed all the bulbs. windshield wipers worked for a day then stopped working at all. Low beams work however when you click to high they go off. No interior lights of any kind. all glass fuses look good and have been changed, I still need to clean all the contacts. Side note there is a white plastic block where a bunch of large connections plug into each other under the passenger well. It looks like a few of the wires have melted at some point I was in the process of assigning the damage before getting pulled away. It does not looks like any of the wires are melted together to the point they are touching metal. Again just worth mentioning. Items missing from the car, I am not sure any of them have dependency of the lighting but worth bringing up. Radio gone Heater and AC controls gone Center dash with fasten seat belt, choke and defrost back window gone. I have the hazard switch connected to the correct spot.... I think... Hey thanks for all your help guys, I will post pictures of my solution when i find it to help others. Thanks Cody Edited September 16, 2015 by rajien2 Quote Link to comment Share on other sites More sharing options...
NewZed Posted September 16, 2015 Share Posted September 16, 2015 No gauges but the speedo and volt meter work, everything else is bellow 0. No tail lights or blinkers of any kind, changed all the bulbs. windshield wipers worked for a day then stopped working at all. Low beams work however when you click to high they go off. Side note there is a white plastic block where a bunch of large connections plug into each other under the passenger well. It looks like a few of the wires have melted at some point Items missing from the car, I am not sure any of them have dependency of the lighting but worth bringing up. Radio gone Heater and AC controls gone Center dash with fasten seat belt, choke and defrost back window gone. I have the hazard switch connected to the correct spot.... I think... The two things that you think are minor are probably major. Melted wires, and all of the loose wire ends from the missing electrical components. Find the loose wire ends and insulate them before you waste too much more time. The melted wires at the connector block. Most of the harness wires pass through that block. In the Body Electrical chapter there's a diagram of each one, with a color code and separate diagrams of what they're connecting. Identify the connector and its melted wires and you'll probably be on your way to finding the short circuit. The headlights only working on either of high or low is a typical dirty dimmer switch problem. Spray some contact cleaner in and work it back and forth or take it apart and clean it. Voltmeter working is a good sign. Quote Link to comment Share on other sites More sharing options...
rajien2 Posted September 16, 2015 Author Share Posted September 16, 2015 Oh fun.... Perfect thank you sir, I will dive into it after work. Thanks for your help Quote Link to comment Share on other sites More sharing options...
seattlejester Posted September 16, 2015 Share Posted September 16, 2015 The voltmeter I think intercepts power from the fuse box (I might be thinking 240z though) so it makes sense that is working. The speedometer is cable driven so that doesn't surprise me that that is working either. You don't need to start with the power source per say. If you have power at the fuse box, start from there. I too must echo that burnt/melted wire is pretty major. Something caused them to melt. Too much amperage or a damaging event. Need to figure that out. If you have a volt meter use it. You shouldn't have to be forced to use it, it should be the first tool you reach for. Quote Link to comment Share on other sites More sharing options...
rajien2 Posted September 16, 2015 Author Share Posted September 16, 2015 What I am currently dealing with, I am tracing the wires on the diagram to figure out what melted... I will post my findings here. Quote Link to comment Share on other sites More sharing options...
rajien2 Posted September 16, 2015 Author Share Posted September 16, 2015 Alright I think that black plug is C-6 and the Green with a white strip is a common wire shared with all my gauges.... This is per the 77 color diagram the car is a 78 so I dont think much changed right? Also on c-6 the yellow should be to my fuel gauge.. Hmm I wonder if all my gauges are fired Quote Link to comment Share on other sites More sharing options...
rajien2 Posted September 16, 2015 Author Share Posted September 16, 2015 (edited) Wow green white is the key... That attaches everything my side markers, horn, tail lights... Good god.. Looks like green and white should be hot. I am still trying to find where is becomes hot at, I have a feeling it might have melted all the way through the wire somewhere... Cut up as far as I could on the steering column wires, the looks good no burns, I need to remove the dash to get to the rest. Thats my next step. Edited September 16, 2015 by rajien2 Quote Link to comment Share on other sites More sharing options...
rajien2 Posted September 17, 2015 Author Share Posted September 17, 2015 Hmmm the harness behind the dash looks just fine, cut the tape and check the wires all the way to the gages. Back to square one, I still think I might have somthing to do with the green/white wire. I need to figure out where is connects to the battery and test it there. Brb after I single handedly put the heavy awkward dash back into place. Quote Link to comment Share on other sites More sharing options...
seattlejester Posted September 17, 2015 Share Posted September 17, 2015 Check continuity at start and finish before you start tearing up the wiring harness. Once you find your break start to isolate and dig it out. Quote Link to comment Share on other sites More sharing options...
rajien2 Posted September 17, 2015 Author Share Posted September 17, 2015 Alright im sorry.... This is going to be a really dumb question.. I understand the principle of checking for continuity in a component like a bulb or fuse by touching each exposed end. Do I need get a multimeter with like a 10 foot cable so I can leave one end in the cab plugged into c-4 and run the other end to the tail socket? Or am I going about this all in the wrong way, again sorry for a basic question. Any tips on finding the issue are completely welcome, as demonstrated I am willing to take the whole car apart Thanks Guys Quote Link to comment Share on other sites More sharing options...
88dangerdan Posted September 17, 2015 Share Posted September 17, 2015 You could grab a couple of alligator clips with a length of wire between them. Quote Link to comment Share on other sites More sharing options...
rajien2 Posted September 17, 2015 Author Share Posted September 17, 2015 (edited) Oh perfect that makes sense thanks 88 AHHH Found it! Power come in from the battery to the dam combination switch! I am going to start there, I have a feeling the issues might be there... It has no cover on it and was left in a barn for 7 years. Edited September 17, 2015 by rajien2 Quote Link to comment Share on other sites More sharing options...
rajien2 Posted September 17, 2015 Author Share Posted September 17, 2015 I am curious about the combo switch if that is broken or removed would it kill all the lights and gauges? I am currently working in the wiring diagram to try and manually trigger the turn signal, I am confused on what that line means between wires does that mean cross them all to make it work?? Quote Link to comment Share on other sites More sharing options...
seattlejester Posted September 17, 2015 Share Posted September 17, 2015 Multiple aligator clips and probing prongs will make it real easy. Keep on going, be methodical and you will find the issue in short time. Quote Link to comment Share on other sites More sharing options...
rajien2 Posted September 17, 2015 Author Share Posted September 17, 2015 Hey thanks SeattleJeseter, Im heading to the store now to pick up pushpins and multiple alligator clips thanks for all your help and support. Quote Link to comment Share on other sites More sharing options...
rajien2 Posted September 18, 2015 Author Share Posted September 18, 2015 (edited) Yikes I have been tracing wire and such and just now realized my combo switch is the same in the diagram..... I don't have a 6 pin connector it's an old 3 pin connector, I need to remove the dash again and trace out where the blinker relay is really going. Could this not be a 1978 280z and something else? Or did they have multiple type of connectors in the same car?? Mine looks like I think it should look like: Man was the PO swapping things around?? Should I just trace all my own wires and buy like 40 switches and create my own at this point?? Edited September 18, 2015 by rajien2 Quote Link to comment Share on other sites More sharing options...
NewZed Posted September 18, 2015 Share Posted September 18, 2015 (edited) What do the harness connections look like? That's the part that normally stays with the car. Your pictures are of the removable stuff. And the door pillar tag will tell you what year car you're working with. What's it say? Edited September 18, 2015 by NewZed Quote Link to comment Share on other sites More sharing options...
rajien2 Posted September 18, 2015 Author Share Posted September 18, 2015 Yikes just pulled the vin up... I guess this is a 76 not a 78? Guess my title is wrong? Quote Link to comment Share on other sites More sharing options...
rajien2 Posted September 18, 2015 Author Share Posted September 18, 2015 Here you go. This is for the high beam switch Turn signal wire This goes to the wipers and headlight turn on Does this look like a 280z? It has no badges anywhere. Quote Link to comment Share on other sites More sharing options...
rajien2 Posted September 18, 2015 Author Share Posted September 18, 2015 (edited) Huh I guess so! this looks right! http://www.atlanticz.ca/zclub/techtips/wiringdiagrams/76_280z_wiring.gif Kinda sad not very colorful or easy to read.. Edited September 18, 2015 by rajien2 Quote Link to comment Share on other sites More sharing options...
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