ragefear Posted August 2, 2008 Share Posted August 2, 2008 I wasn't sure where to put this, I thought about putting it in the electrical section but I don't know if it would get the proper response. When it comes to wiring this car I am completely confused. I pulled both wiring harnesses and pulled the ECU as well. It looks as tho the only thing I really need the ECU to do is to run the fuel pump? By rights I should really just swap that out anyway, correct? So do I even need the driver side wiring harness? The passenger side harness, I figured that I could get rid of most of the relays and maybe just keep the lights, the oil pressure wiring, wipers, and that's really it... or maybe I should get the motor in and running before I decide to tear everything down? Quote Link to comment Share on other sites More sharing options...
worknprog Posted August 2, 2008 Share Posted August 2, 2008 Ragefear, boy it sure seems that we are just about in the same boat. I was just going to install the LS1, as I started to clean the engine bay and pulling the harness back I found rust on my flor boards. It seems the more I look at it , the more I need to do. My understanding as far as the fuel pump goes is that the ecm from the ls1 harness controls it and the ignition turns it on. My understanding is that you don't need the pcm fromn the Datrsun at all. Quote Link to comment Share on other sites More sharing options...
Dudeboy Posted August 2, 2008 Share Posted August 2, 2008 This is a electrical/LS1 answer !! ragefear, If you removed both the Datsun engine harness (replaced by the LS1 ECM and harness) and the stock chassis harness, you have to replace the chassis harness as well . If you look at your Z factory manual, you will see were they meet (a terminal block) or junction block on the passenger side foot well. Some guys have built there chassis harness, most here have gone with Painless harness--I am using a Summit Gm 18 circuit harness.I am doing my wiring right now (wiring the guages in the dash) and next week with nothing scheduled get started on the chassis electric. The electrical experts who have done LS1 swaps hopefully will chime in, you have to decide if you are going with the stock chassis harness and removed some of the items you may not need per JTR manual and hopefully you want remove something you need, or replace with a new chassis harness. It was confusing to me at first, but if you look at how your engine harness is labeled and look at a Painless harness manual you will see were the circuits meet. You will have some items work when you turn your key to accessory and/or ignition -or you may decide to go with toggle switches. Shoot me a PM, oddly enough the electric stuff finally was logical to me (Thanks Warren !!) Quote Link to comment Share on other sites More sharing options...
zed240au Posted August 3, 2008 Share Posted August 3, 2008 well i can only say how i did my ls1 I left std datsun wiring loom in place (well intact and rerouted to keep engine bay clean) i used the std oil pressure and temperature pick ups to run std guages the alternator light std alternator lead to alternator i had my std ls1 loom modified so that guy removed all plugs i didnt need and fitted leads out of it that i needed to supply inputs to or control from pcm as well as fitting relays and power supply to pcm hot ignition feed for starting ,starter feed and power feed from igntion when in run position leads out of ls1 loom where tacho feed speedo signal feed voltage pickup fuel pump power lead thermo fan lead reverse light feed fitted relays for thermo fans and fuel pump starter and igntion hope that helps mick Quote Link to comment Share on other sites More sharing options...
milesz Posted August 3, 2008 Share Posted August 3, 2008 I wasn't sure where to put this, I thought about putting it in the electrical section but I don't know if it would get the proper response. When it comes to wiring this car I am completely confused. I pulled both wiring harnesses and pulled the ECU as well. It looks as tho the only thing I really need the ECU to do is to run the fuel pump? By rights I should really just swap that out anyway, correct? So do I even need the driver side wiring harness? The passenger side harness, I figured that I could get rid of most of the relays and maybe just keep the lights, the oil pressure wiring, wipers, and that's really it... or maybe I should get the motor in and running before I decide to tear everything down? I sent mines to Engine Wiring and they did a great job. Not only did they reworked the V8 wiring harness to fit my application, they also reprogram the ECU. I only had to connect a few wires and the way I go. Save your the headache, farm it out. Quote Link to comment Share on other sites More sharing options...
bjhines Posted August 3, 2008 Share Posted August 3, 2008 Well... You have a lot of things to consider. The front clip lighting, Alternator, Vreg, main power, front-clip gorunds, and a few other handy things are in the engine bay harness. You need those lights if nothing else. You could trace all of the wires you need back to the connector under the dash and cut them all off there. Then you can combine the LS1 harness and the original main plug(and light connectors) into one new harness to keep it neat and NEW. What are you going to do about an alternator? Modern alternators like the CS-130/130D used in late model GM vehicles can do all sorts of fancy things to regulate power. They are not at all like an early SI- type alternator. The modern alternators were designed to give the ECM all sorts of feedback about the car's power management. The ECM can use this information to change idle speed to meet electrical demands when sitting still in traffic. The ECM can momentarily disable the alternator's field-coils to reduce the parasitic HP loss at high RPMs and Full Throttle. There is also a square-wave RPM output from a modern alternator's V-regulator. Quote Link to comment Share on other sites More sharing options...
ragefear Posted August 4, 2008 Author Share Posted August 4, 2008 The modern alternators were designed to give the ECM all sorts of feedback about the car's power management. The ECM can use this information to change idle speed to meet electrical demands when sitting still in traffic. The ECM can momentarily disable the alternator's field-coils to reduce the parasitic HP loss at high RPMs and Full Throttle. There is also a square-wave RPM output from a modern alternator's V-regulator. :icon52: I had no idea... Quote Link to comment Share on other sites More sharing options...
mark Posted August 4, 2008 Share Posted August 4, 2008 BJ, Do you have a link to this info? I'm having charging issues at high RPM's on the ls-1 z car. It seems like the altermator cuts out at high RPMS. This info would explain that. Thanks Well... You have a lot of things to consider. The front clip lighting, Alternator, Vreg, main power, front-clip gorunds, and a few other handy things are in the engine bay harness. You need those lights if nothing else. You could trace all of the wires you need back to the connector under the dash and cut them all off there. Then you can combine the LS1 harness and the original main plug(and light connectors) into one new harness to keep it neat and NEW. What are you going to do about an alternator? Modern alternators like the CS-130/130D used in late model GM vehicles can do all sorts of fancy things to regulate power. They are not at all like an early SI- type alternator. The modern alternators were designed to give the ECM all sorts of feedback about the car's power management. The ECM can use this information to change idle speed to meet electrical demands when sitting still in traffic. The ECM can momentarily disable the alternator's field-coils to reduce the parasitic HP loss at high RPMs and Full Throttle. There is also a square-wave RPM output from a modern alternator's V-regulator. Quote Link to comment Share on other sites More sharing options...
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