Nismo280zEd Posted March 29, 2005 Share Posted March 29, 2005 Ok guys, as mentioned I've been doing alot of re-wiring. I wanted to put dual relays on my headlights to save the switch as i had once catch fire previously on me. Basically I'm following the diagramn from Susquehanna Motorsports this link... http://www.rallylights.com/useful_info/headlamp_wiring.htm Ok... now I have a 78 280z 2+2... I powered the part of the fuse box for headlights directly from the battery. Now there is a Right and Left headlight on the box, I'm using these as Highbeam and Lowbeam. the one with the red-yellow wire i'm using as high beam previously the Left headlight I believe, obviously the other one is low beam. I have these two wires coming into my relays on the "30" position on both relays as the diagramn shows. Then I have two seperate wires running to the headlights just as the diagramn shows, one lowbeam one highbeam. I also have both relays grounded. Now here is the problem.. on my switching wires terminal "86" I can only get one relay to click or power up. From the headlight switch I ran an ignition power wire the huge redwire (so the lights would shut off when the car is turned off) then the white-red wire I connected to my switching wire from terminal "86".. This works fine, turn the lights on it powers up. Now the High beam switch is confusing me a bit. There are two wires used by it. A black-red wire and a white red wire. By following Oem diagrams you find the white-red wire is the high beam wire (unless i'm reading this wrong) then the black-red wire is low beam according to the diagramns. So I thought about this... basically the switch is not doing anything on low beam (the black-red wire connecting to ground) then you switch it and the highbeams come on and it connects the red-white wire to ground. The black red wire runs all the way to my headlights as OEM the lights are not grounded to battery like in the motorsports diagramn. ok now I have the red white wire connecting to my switch wire for terminal "86" on my relay. Obviously this is not right.... I'm thinkn' I should just ground out the headlights, then run power into the red-white wire and use the red-black wire as my switching wire? This has me scratching my head and staring at wiring diagramns. I'd much appreciate any help on this! -Ed Quote Link to comment Share on other sites More sharing options...
Nismo280zEd Posted March 29, 2005 Author Share Posted March 29, 2005 I want to add to this.. I'll be accepting any old Z fuse boxes. -Ed Quote Link to comment Share on other sites More sharing options...
Nigel Posted March 29, 2005 Share Posted March 29, 2005 Below is my relay conversion specifically for the Z. It's based on 240Z wiring diagrams, but I think the wire colours are the same for the 280. To clarify, the 1A fuse in the diagram is one of the pre-existing fuses in the fuse box. It would normaly be 10A, but after the conversion, only a 1A is required. All you have to do is cut four wires in the engine bay harness: Red/White Red/Black Red (There are two red wires in the harness. The larger diameter of the two is the correct wire - the other is for fog lights) Red/Yellow On the headlight side of the cut: Red and red/yellow get connected to ground. Connect the Red/White wire to terminal 87 on the high beam relay via a 12 guage wire. Red/Black connects to terminal 87 on the low beam relay via a 14 guage wire. On the cockpit side of the cut: Connect the Red/Yellow wire to terminal 85 on both relays via an 18 guage wire (NOTE: in my drawing, I show the Red wire for this connection. This will work, but the high beam light on the speedometer will not turn on!). The red/white wire connects to terminal 86 on the high beam relay via an 18 guage wire. The red/black wire connects to terminal 86 on the low beam relay (via 18 guage wire). The red wire is left disconnected. Connect terminal 30 on both relays to a 30 amp fuse using 12 guage wire to the high beam relay and 14 guage to the low beam relay. The fuse connects to the positive terminal on the battery. To be safe, idealy the high and low beam circuits should be separately fused because of the different wire gauges (20A for high beam and 15A for low beam). I haven't updated my drawing yet. I tried to follow your explanation, but it's 3am and I'm not thinking too clearly right now! Basically, for high/low beam control you should be switching the relay coil grounds, not the actual headlight grounds, which is what it sounds like you're doing. Nigel '73 240ZT Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted March 29, 2005 Share Posted March 29, 2005 I used Pete's circuit, works fine! http://alteredz.com/Headlight_Relay_pg1.htm http://home.comcast.net/~pparaska/image/electrical/Headlight_Relay_Diagram.jpg Quote Link to comment Share on other sites More sharing options...
Nismo280zEd Posted March 29, 2005 Author Share Posted March 29, 2005 thanks for the quick response Nigel. I'm gonna see if I can't get it to work today with help of your diagramns and the other. I really need to get a dang electricians book. I tend to over complicate things. -Ed Quote Link to comment Share on other sites More sharing options...
Nismo280zEd Posted March 30, 2005 Author Share Posted March 30, 2005 Yeah I got it figured out... The wiring is a lil different for the 280.. but nothing complicated, just different colors. The new Hellas shine like the North star hehe. now i just gotta run a splice off a wire to go to the indicator behind the speedo for high beam. Thanx for the quick response. -Ed Quote Link to comment Share on other sites More sharing options...
nienberg.11 Posted May 7, 2006 Share Posted May 7, 2006 Ed, I don't suppose you recall what the difference in wire coloration between the 240 and 280 was? I got pulled over for having a headlight out (it was actually on, but so dim as to be useless) so I added relays to the circuit yesterday but my lights aren't coming on. I don't have a multimeter or test light with me here at college so I'm having trouble figuring out where I went wrong. Quote Link to comment Share on other sites More sharing options...
Nismo280zEd Posted May 7, 2006 Author Share Posted May 7, 2006 Yeah I can go look at at the wires when i get home... i'm at work now.. i'll post it back to ya when i'm on the computer later. you need the 280 colors right? -Ed Quote Link to comment Share on other sites More sharing options...
nienberg.11 Posted May 7, 2006 Share Posted May 7, 2006 Thanks, and yeah I need the 280 colors. Quote Link to comment Share on other sites More sharing options...
Sean73 Posted May 7, 2006 Share Posted May 7, 2006 I used the heavy duty headlight wiring kit from victoria british. It's $30, and a no-brainer to install. No splicing into stock harness required. I did have to extend the wires in the kit to route it the way I wanted though. Quote Link to comment Share on other sites More sharing options...
nienberg.11 Posted May 7, 2006 Share Posted May 7, 2006 Ed, don't bother checking into that for me. I got it figured out. Sean, I had looked into that kit before, but the one light just went all dim the other day and after getting pulled over for it I decided to do it myself for the sake of timeliness. That was a lot of soldering, splicing, etc (especially since I messed some things up the first time around) and I also had to replace the socket on one of the bulbs because it was so corroded, but it's done now and the lights seem to be brighter. I won't know for sure until I leave work tonight since it was a very sunny day here. Quote Link to comment Share on other sites More sharing options...
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