Glliw Posted August 8, 2013 Share Posted August 8, 2013 The other night I was driving the car and out of the blue the dash lights went out on me. There have been no electrical changes to the car that would warrant this. I have so far checked: combo switch contacts - had some carbon build up that i cleaned up with sandpaper and swapped headlight for parking lights - no effect no blown fuses the black fusible link for alternator/ign switch relay was melted but not burned through. All other fusible links look good. So what should I check next? I'm thinking the dimmer switch but I have no idea what to do to test a rheostat. Also, where's a good source for a new fusible link? I don't want to make the $60 jump to a maxi-fuse setup quite yet. My local Autozone didn't have anything (or anyone) useful in stock. Quote Link to comment Share on other sites More sharing options...
Miles Posted August 8, 2013 Share Posted August 8, 2013 Down load a FSM from the Links forum on HybridZ and also get a Haynes maual for your car. The Haynes manual has an electrical schematic. Trace the affected circuits on the schematic and check for broken wires and loose connectors. Fusible link: http://www.zcarparts.com/ or try Black Dragon, Napa etc. Quote Link to comment Share on other sites More sharing options...
djwarner Posted August 8, 2013 Share Posted August 8, 2013 All of these lights are on the same fuse on the right side of the fuse panel. I had a similar problem in my '71 Series I, turned out to be corrosion on the back side of the fuse panel. I could measure 12V on both sides of the fuse, but only 7 volts at a center terminal of a bulb socket. Since it is affecting both the running lights and instruments lights, I would suspect the problem will be found inside the car. An easy place to measure the voltage at a socket is the service light under the hood. It is on the same fuse. Quote Link to comment Share on other sites More sharing options...
Glliw Posted August 9, 2013 Author Share Posted August 9, 2013 Thanks for the info, djwarner. I took another look at it tonight. The back side of the fuse box looks good...no corrosion there. I got them working...for about 2 minutes. I was checking voltages across the fuses (which is practically nothing for all fuses with the engine running...) and when I sat back to stretch out from being bent over, I fiddled with the dome light. It was flickery when pushed but when nudged over to the one side it stayed on and voila! the lights came back on. Two minutes later and the top right fuse blew. So I'm guessing its a poor connection in that dome light that's causing problems or am I off on this? Quote Link to comment Share on other sites More sharing options...
masta tech Posted August 11, 2013 Share Posted August 11, 2013 Sounds right mate pull the dome light out and hav a look . Quote Link to comment Share on other sites More sharing options...
Glliw Posted August 11, 2013 Author Share Posted August 11, 2013 So I pulled the dome light off and those contacts look beautiful. I pulled the bulb out and inspected it and the filament looked good, though one of the "contact cones" on the bulb fell off when I was trying to get it back in there. This was probably the loose connection that jiggling the light was fixing. So looks like a new bulb might just solve that but I tried to see if it'd work without the bulb as well as a wire jumped between the two leads and I got nothing in return... Quote Link to comment Share on other sites More sharing options...
NewZed Posted August 11, 2013 Share Posted August 11, 2013 Coincidence? Did you have your hand on something else while fiddling with the dome light? The dome light has constant power but only grounds through the door switches or the switch at the light itself. BE-16. My instrument lights and running lights went out when the wire to the top of the switch broke off. But ti sounds like you've checked that, and confirmed it's good with the hedlight circuit swap. How about the rheostat circuit? That's the ground for the instrument lights, through C-1 which, coincident to the lights coming back on, is down by the fuse box. BE-15. Quote Link to comment Share on other sites More sharing options...
Glliw Posted August 12, 2013 Author Share Posted August 12, 2013 Nope, I wasn't touching anything else at the time. You're saying the solder joint on top of the combo switch for you failed? Mine look in good shape so shouldn't be my issue, as I get voltage at the switch. The rheostat is what I suspect but I have no idea how to check one. So you're thinking I might have an issue with that Black wire going from the rheostat to C-1? Quote Link to comment Share on other sites More sharing options...
NewZed Posted August 12, 2013 Share Posted August 12, 2013 The solder joint fatigued and broke underneath the big blob of solder. Looked like it was still connected but was just sitting above, no electrical connection. If you were pressing down on the shiny solder blob with a probe you might measure continuity or voltage, that would then go away when the probe was removed and the wire end lifted. I think that it's fairly common. It's a heating/cooling/vibration fatigue that cracks it. Grab the wire and tug. If it comes free, that's a problem. C-1 is where the actual ground point is. Maybe you lost ground there. Find C-1 and jumper the pin through the back side or something, or measure voltage at the pin with the switch on. The diagram of C-1's location and the rheostat pin is on the page I referenced above. Quote Link to comment Share on other sites More sharing options...
Glliw Posted August 16, 2013 Author Share Posted August 16, 2013 I looked at C-1 and the whole underside of the dash area and nothing was a glaring issue. I did not get a chance to measure the voltage at the pin though as I was running out of light and time from helping my neighbor on their car (this is what I get for leaving the garage door open!). The wires at switch have a good connection. Looking at BE-15 on the top half a 20A fuse is shown between the switch and fusible link, but the fuse on the block that is use is the upper right "PT" 15A fuse. Is there another fuse in the system somewhere that I'm missing? I still suspect rheostat failure though no clue how to test one. Quote Link to comment Share on other sites More sharing options...
Glliw Posted August 17, 2013 Author Share Posted August 17, 2013 A little update for the day: continuity checked out from Green with blue stripe (GL) at switch to the fuse block. battery voltage seen between the right side of the fuses to green with white switch (GW) Looking at BE-15, GL seems to be pretty simple, with it being a direct path from switch to fuse with no other wires coming into it. GW is fairly complex. From what I can understand, GW picks up hazards, radio and heater. The radio works. The hazards do not, but I suspect that's a result of the front end damage, as they took a beating from the PO. Any pointers here? Quote Link to comment Share on other sites More sharing options...
Glliw Posted August 22, 2013 Author Share Posted August 22, 2013 Looks like an issue at the switch...time for a new one I guess... http://www.youtube.com/watch?v=EI0JGK1u_zA Quote Link to comment Share on other sites More sharing options...
Domzs Posted August 22, 2013 Share Posted August 22, 2013 Fact radio ? Quote Link to comment Share on other sites More sharing options...
jimskillet Posted August 24, 2013 Share Posted August 24, 2013 I have been suffereing from this exact same issue for weeks now and finally tried unscrewing all my side markers, pulling out the bulbs and making sure to pull out and clean up all wires connected to the sockets (especially the rears). Apparently there is a ground issue with one of the wires touching something it's not supposed to. All I needed to do was make sure to clean up the wires and keep the wires away from touching the body. Re-insert the 4 bulbs and turn on your lights before screwing everything back on. If it doesn't work immediately, try wiggling each of the wires and reorganizing them. Let me know if that works. My dash and tail lights came back on instantly after doing this. Quote Link to comment Share on other sites More sharing options...
djwarner Posted August 24, 2013 Share Posted August 24, 2013 (edited) Had a similar problem when the car came out of the body shop after an accident. Blowing fuses. Turned out the body shop guy got over spray on the wiring for the side marker lights on one side. When the car was re-assemble for the last time, he reversed the ground and power leads to the light. Since the Datsun lighting systems include both a wire ground AND a chassis ground loop, reversing the leads at the light put the power lead to the chassis ground popping the fuse. Edited August 24, 2013 by djwarner Quote Link to comment Share on other sites More sharing options...
jimskillet Posted August 26, 2013 Share Posted August 26, 2013 (edited) Had a similar problem when the car came out of the body shop after an accident. Blowing fuses. Turned out the body shop guy got over spray on the wiring for the side marker lights on one side. When the car was re-assemble for the last time, he reversed the ground and power leads to the light. Since the Datsun lighting systems include both a wire ground AND a chassis ground loop, reversing the leads at the light put the power lead to the chassis ground popping the fuse. This was the same problem with my car. I noticed overspray on the wiring of the side marker light on one side. Edited August 26, 2013 by jimskillet Quote Link to comment Share on other sites More sharing options...
IncompetentOne Posted November 25, 2013 Share Posted November 25, 2013 Not to pester here, hoping this is still somewhat alive. My 77 280z recently developed a familiar problem. My interior lights and headlights do not work, but they were fine a month ago. When I hit the switch, the volt guage drops below the lowest possible reading, also, when I am driving along on the road, it read where it should, right at 13-15 volts. But when I press on the brakes, the gauge goes below the lowest reading again. I know that this is a wiring issue, I just need a pointer on where to look. Thanks for any help! Quote Link to comment Share on other sites More sharing options...
djwarner Posted November 25, 2013 Share Posted November 25, 2013 First things first. Check the water level in your battery, check for corrosion on the battery terminals and in wires connected to them, and then take the battery to Wally World and get it tested. Normally corrosion in the load side of the circuits increases the resistance reducing current flow. This would result in voltage remaining high. Before starting the engine, turn the ignition to run and turn on the suspect load. Observe the ammeter. If the meter deflects a small amount, suspect the battery side of the circuit. If it deflect a large amount, there may be a short in the load circuit - but that should be popping the fuse. There are two large spade connectors in the wire bundle on the passenger side of the center console. The wires for the connectors are white and white with a red stripe. These connectors are on the power side of the circuits and corrosion in these connectors may also cause a voltage sag. Quote Link to comment Share on other sites More sharing options...
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