jacob80 Posted April 18, 2009 Share Posted April 18, 2009 Hey guys, We have a '73 240z and we're wiring megasquirt. Currently, we're using the switched 12v source on the driver side on the harness section that has the tach wiring and such, but we need another souce because we have 3+ wires which include the distributor positive, fan positive, and the resisted wire that T's off the distributor green/white (those colors may be inaccurate, but close). My question is, where is another switched 12v source close to the firewall because we need to run power to the relay board which is mounted right near the battery. Thanks! Quote Link to comment Share on other sites More sharing options...
GrayZee Posted April 18, 2009 Share Posted April 18, 2009 I don't think there is alot on a 240z as there isn't alot of need for wiring in the first place. Have you considered using that 12v switched source you already have to run a relay instead? Then you could easily run alot more circuits coming right off the battery. Quote Link to comment Share on other sites More sharing options...
jeffer949 Posted April 18, 2009 Share Posted April 18, 2009 I ran mine right off of the fusible links if im not mistaken. And you dont need much power for the switched power source. Its only activating the main power relay on the relay board. Quote Link to comment Share on other sites More sharing options...
sTonedaZn Posted April 18, 2009 Share Posted April 18, 2009 do you guys know where I can get step by step with pics. That might be better than what i'm trying to do now. 1 week 79'280zx dizzy with 73 240z 20miles from home = no progress Quote Link to comment Share on other sites More sharing options...
Guest Rolling Parts Posted April 21, 2009 Share Posted April 21, 2009 You can use the Relay Board (which was made to convert a simple carbed car to EFI). If you want to wire up the new EFI without a relay board, you'll need to get a power relay and a simple fuse holder from AutoZone to run MS from a central fused location. You will need fuses for the MS, Injectors, EFI rated fuel pump, and probably O2 sensor. Don't try to run that ~25 amps of draw from just some wire you find under the dash, each part "should" be fused sepparately. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted April 22, 2009 Author Share Posted April 22, 2009 Ok well we've wired everything else but the wideband. My first quesiton is, we have the LC-1 lambda and the cable actually has that built in controller integrated into the cable, where did you guys mount yours? Also, can I get 5A of power from the fuse box? If not, where can I pull power for this from under the dash?? Quote Link to comment Share on other sites More sharing options...
AtlantaZ Posted January 11, 2011 Share Posted January 11, 2011 I have a '76 280z and am getting ready to drop in Megasquirt II V3.0 myself (with a relay board). Anyone have a good recommendation for the CRANK/RUN 12V switched voltage source for my relay board? Quote Link to comment Share on other sites More sharing options...
madkaw Posted January 11, 2011 Share Posted January 11, 2011 jacob, I am also just finishing up installing my LC-1 and I ended up laying mine under my center console. I am ASSuming that I won't need to access the controller plug, but the serial ports only. I just wanted it out of the way and I found a hole for it under the console by the fuse box. The harder part was finding a place for all the extra cable wires that came with the controller. As far as a power goes, I poked around with my meter since I had my heater panel out and searched for a 12v switched. I found(going by memory here) a hot switched that was an extra wire off of the blower fan plug. I believe the amp draw is very small for the LC-1 since it only requires a 5amp fuse, so I would think any power source would be okay. On a 73 you should have a fuel pump wire that is fused under there somewhere, unless you are actually using the electric pump wiring. A side note, grounding procedure is critical with all of your components, so take care to follow instructions there. Quote Link to comment Share on other sites More sharing options...
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