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Rb25det vl wiring

Started by Dinodore · 26 Aug 2013 · 28 replies

Preserved from CalaisTurbo. Original authors and dates are shown; archived members are not current Holdcom accounts. View original archive ↗

PSI086Archived member
The plug on the vl starter will have a white and a blue/white wire going into it. The white goes to the alternator and the blue/white is your cranking signal. Those 2 wires also go through the 4 pin grey plus which has the 4mm wires in it as well from memory. There should be a spare plug on the 25 loom that has all the power source wires in it. Trace which one you need to tap into at the relay with a multimeter. Do the relay pins have numbers on them? It's been a while since I've looked closely at a skyline loom
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SteveArchived member
Quote: Originally Posted by Dinodore [View Post] There is no black/white wire in the small white plug. ---------- Post added 31-08-13 at 16:28 ---------- I got told to tap constant power into the black white strip wire in the relay. The website says the white wire black strip on the long white plug You said the black/white wire in the smaller white plug. Which one is ittttttt Haha oops yeah thats wat I meant. What ever that link says..
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DinodoreArchived member
What wires do I need to hook up on the back of my alternator apart from the plug? Like where does the red and black cables attach to
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PSI086Archived member
Red cable goes to the battery lug on the starter, brown goes to the battery light in your dash, white goes to the starter also and it may also have an earth strap on it which just goes to the block. They are the VL colours but you should be able to work out which is the dash wire (brown vl) and which is the sense wire (white vl) as the plug is the same depending on your RB30 alternator type
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DinodoreArchived member
I already hooked up a red cable to the starter and theres another one so I thought it had to go to the alternator. I believe im running a vl alternator as it says bosch 70 amp on the side of the rear black cover. If i have the 30 alt it earths through the mount on the block and i dont need to run an extra earth right?
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DinodoreArchived member
I cranked it today and it cranked over smoothly. I didnt mean to crank it for long so it wouldnt start because the intercooler isnt hooked up yet, but I accidentally let it fire for a second and I heard it run for a tiny amount of time Might be onto a winner here Some original photos have not been recovered yet.
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DinodoreArchived member
What size resistor do I need to wire up the tacho signal?
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vh 25detArchived member
Quote: Originally Posted by Ant_man [View Post] First thing i need to know is if its a series 1 or series 2 rb25 loom easiest way to tell is by the relays next to the ecu if has 2 its a series 1 if has a single relay its a series 2 loom If all you want to do is start it with a standard ecu its fairly easy at the body connector under the air cond box connect up these wires vl rb25 Green - standard fuel pump signal to Black purple strip - fuel pump signal Fat black red strip - Switch power Thin black white strip - Constant power Blue white strip - Switch power with these wired in at body plug and everything on the rb25 connected such as afm cas etc it will start and run but if you want to wire it in properly here is a short run down. Alternator, Starter, Etc.: The easiest way to wire the driver�s side loom is to graft the RB30 loom onto the 25. Undo all the wires off the RB25 alternator, starter and oil pressure sender. � Remove all the tape and conduit shielding from the loom and separate the knock sensor wiring from the rest. � The knock sensors are the two sensors at the top of the block under the intake plenum. � Remove the RB25 alternator and bolt on the RB30 one. � Unplug the RB30's driver�s side loom from the car (or RB30 if you kept it attached) and attach it to the RB25's knock sensor wiring. Plug in the alternator and starter motor. You can use the RB25 starter with the RB30 wiring no worries. � Remove the RB30 oil pressure sender unit from the RB30 block and screw it in place of the one on the RB25. Plug it into the RB30 loom now on the RB25. � Cover the loom with the conduit wrapping and electrical tape to neaten it up. � Grab the main earth wire off the RB30 block and put it in place of the one from the RB25. Fuel Pump The fuel pump in an R33 is earthed through the ECU. Series 1 loom in the foot well plug (long white one ON THE ENGINE LOOM NOT THE CARS DASH\BODY LOOM) thin white/black - constant 12v thickish red - ign 12v through a pair of 6A diodes (or one big one making sure the silver bands face the way u want the current to flow) to stop voltage flowing backwards to ground. If you don't use diodes the ignition won't turn off. Black/red - ign 12v yellow/blue - tacho, using the pull up circuit already detailed. Light blue/white - ign 12v, it�s for the vct and 02 sensor black/purple - fuel pump relay control Dark blue/black - temp gauge grey/red - 12v under cranking There are only two wires needed to make the Engine start now. One needs constant power and the other needs ignition power. � ECU plugs white wire with black trace. Tap the constant power in to it. � Thick black wire with red trace (BR). Tap ignition power into this wire. Now if your fuel pump primes and shuts off after a few seconds you've done it correctly. At this stage the engine should run if everything else is done. Tachometer � Find tacho signal wire from the dash plug. � Coming out of pin 7 on the ECU is a yellow wire with red trace (YR). This is the tacho signal to the ECU. You could splice a wire into this but I'd advice looking in the engine bay and finding a small rounded plug on the afm branch by the passenger strut tower. It has a single wire going into it and a rubber cap on the end. The wire is yellow with blue trace (YL). This is also RPM signal. Attach to tacho signal wire. � Now you'll need to go grab a 10k resistor. You'll need to splice a wire into wire 49 from the ECU, run it through your resistor, and finally splice it into the tacho signal wire. hi guys, sorry to bring up an old thread but i cant find anything else on line about diodes for the ignition to stay off. i'v recently done a rb25det conversion on my vh commodore. all is good except my ignition is staying on. i tried the 6 amp diodes in the ignition feeds that i ran to the ecu but it didn't fix the problem. am i missing something simple? i don't have any "thickish red wire" to attach the diodes to as described above.... i tried the diodes in line on both ignition feeds i used, but the problem was still there. does anyone know the pin out number on the ecu for the circuit they need to be used in? any help appreciated. Thanks
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Avl30/25Archived member
Hi guys new to the forum just finding as much info as i can as im doing the 30/25 i see alot of info here in the conversion i personally just would like someone to tell me what wire goes where from Vl blue and white plug and black and purple plug to the rb25det engine harness in the simplest way possible ie vl wire colour trace and name to rb25det colour wire trace cheers Muchly appreciated
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