Posted March 31, 200817 yr comment_242524 Hello,The headlights on my 1975 280Z does not work. I used a test light to test the three wires that plug onto the headlight and no power.The park lamps turn on. The turn signals don't. The high beams don't work either.I also noticed that at the steering column, there is a black (thin) wire that is not connected anywhere. My guess is that it should connect to the ignition??I cannot remember the color of the other wire to the ignition, (White and red, or red)... but should the black wire also go to the ignition.Is the open black wire at the steering column the reason the headlight is not working?What can I do to get the headlights working? Please help. Link to comment https://www.classiczcars.com/forums/topic/27571-no-headlights-on-1975-280z/ Share on other sites More sharing options...
March 31, 200817 yr comment_242529 Have you checked the fuses? Link to comment https://www.classiczcars.com/forums/topic/27571-no-headlights-on-1975-280z/#findComment-242529 Share on other sites More sharing options...
March 31, 200817 yr Author comment_242531 None of the fuses in the fuse block are blown. Are there other fuses I should check in the engine compartment?Should I check for continuity at the fuse block ?? At this point, I am not sure where to start? Link to comment https://www.classiczcars.com/forums/topic/27571-no-headlights-on-1975-280z/#findComment-242531 Share on other sites More sharing options...
March 31, 200817 yr comment_242542 Definitely check for that Black wire's corresponding connector. The Hi/Lo Beam switch requires a Black wire connect to the Combination Switch as well as a joint connection to the Windshield Washer. (As a check, you might check your W/Washer to see if it is operating.)E Link to comment https://www.classiczcars.com/forums/topic/27571-no-headlights-on-1975-280z/#findComment-242542 Share on other sites More sharing options...
April 1, 200817 yr Author comment_242665 I am getting my car back from the shop today.. I will look into that black wire and get back.. Wish me luck..! Thanks for your input. Its appreciated. Link to comment https://www.classiczcars.com/forums/topic/27571-no-headlights-on-1975-280z/#findComment-242665 Share on other sites More sharing options...
April 11, 200817 yr Author comment_243788 OK. I finally got to take a look at a few things. Here are my observations using a test light. A)Tested the wires on the top of the combination switch and observed the following. SWITCH OFF 1 2 WR ON ON ON R OFF OFF ON GW OFF ON ON G ON ON ON Is the above what I should expect. I tested the wires at the bottom of the combination switch and observed the following. I don't know what those wires are for? SWITCH OFF 1 2 RB OFF OFF OFF BY OFF OFF OFF B OFF OFF OFF WB OFF OFF OFF hmm.. does that make sense I will test the fuse box next. The fuses should be on the two on the top left? can someone confirm. I don't have a fuse box cover. Should they be on at all times or should they be on only when I turn the switch on to the 1 and 2 position? Thanks a million. Link to comment https://www.classiczcars.com/forums/topic/27571-no-headlights-on-1975-280z/#findComment-243788 Share on other sites More sharing options...
April 11, 200817 yr comment_243801 They are the top two. here is a pic of the fuse box. I would replace them even if they look good. I had some that looked good but were bad. Plus some worked until i touched them! Link to comment https://www.classiczcars.com/forums/topic/27571-no-headlights-on-1975-280z/#findComment-243801 Share on other sites More sharing options...
April 11, 200817 yr Author comment_243835 They are the top two. here is a pic of the fuse box. I would replace them even if they look good. I had some that looked good but were bad. Plus some worked until i touched them! Thanks for the diagram.. at least now I can test the right fuses. What are your thoughts on the observations I made on the combination switch. Do those look right?Anyone.? Link to comment https://www.classiczcars.com/forums/topic/27571-no-headlights-on-1975-280z/#findComment-243835 Share on other sites More sharing options...
April 14, 200817 yr Author comment_244143 OK. I finally got to take a look at a few things. Here are my observations using a test light.A)Tested the wires on the top of the combination switch and observed the following. SWITCH OFF 1 2 WR ON ON ON R OFF OFF ON GW OFF ON ON G ON ON ON Is the above what I should expect. I tested the wires at the bottom of the combination switch and observed the following. I don't know what those wires are for? SWITCH OFF 1 2 RB OFF OFF OFF BY OFF OFF OFF B OFF OFF OFF WB OFF OFF OFF hmm.. does that make sense I will test the fuse box next. The fuses should be on the two on the top left? can someone confirm. I don't have a fuse box cover. Should they be on at all times or should they be on only when I turn the switch on to the 1 and 2 position? Thanks a million. Can someone help me on my question above.? Please.... I really appreciate it. Link to comment https://www.classiczcars.com/forums/topic/27571-no-headlights-on-1975-280z/#findComment-244143 Share on other sites More sharing options...
April 14, 200817 yr comment_244155 The biggest problem with your test, is that you don't specify WHAT it is you're testing for. Add to that that you don't reference with respect to WHAT you are testing against.ON = What? Voltage 12v or continuity? Continuity with regards to what? Voltage with regards to what?Have you checked the wiring diagram for your year? Did you check and/or replace those fuses? (Note a VISUAL check of the fuses is worthless, these glass tube fuses often look OK, but in fact are NOT.)Have you checked to see if you have power at the headlamp connector?Not trying to p*ss you off, but we can't see your car from where we're sitting, which makes it extremely hard to diagnose.2¢E Link to comment https://www.classiczcars.com/forums/topic/27571-no-headlights-on-1975-280z/#findComment-244155 Share on other sites More sharing options...
April 15, 200817 yr Author comment_244236 The biggest problem with your test, is that you don't specify WHAT it is you're testing for. Add to that that you don't reference with respect to WHAT you are testing against.I am testing to determine why my headlight is not working.ON = What? Voltage 12v or continuity? Continuity with regards to what? Voltage with regards to what?I am checking for continuity. For example, when I turn the headlight switch once, the WR (white red) wire has power when I attach the test light to it... thus, "ON".Have you checked the wiring diagram for your year? I have been studying the wiring diagram.. but sometimes checking in with folks helps... nevertheless, I will visit it again.Did you check and/or replace those fuses? (Note a VISUAL check of the fuses is worthless, these glass tube fuses often look OK, but in fact are NOT.)I replaced all the fuses with the correct ones. I cleaned all the connectors too.Have you checked to see if you have power at the headlamp connector?There is power at the fuses for the headlights.. I tested all points of contact at the fuses for continuity.There is no power at the headlamp connector for both headlights.Not trying to p*ss you off, but we can't see your car from where we're sitting, which makes it extremely hard to diagnose.2¢EI hope this helps. .. and sorry for the inconvenience. Link to comment https://www.classiczcars.com/forums/topic/27571-no-headlights-on-1975-280z/#findComment-244236 Share on other sites More sharing options...
April 15, 200817 yr comment_244240 This exact problem happen to me on my 78 280z one time, and I found it was in the wiring harness at the firewall under the battery box where acid had melted the wire insulation.Hope this helps! Link to comment https://www.classiczcars.com/forums/topic/27571-no-headlights-on-1975-280z/#findComment-244240 Share on other sites More sharing options...
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