RB20 Alternator wiring

Discuss the RB20, RB25 and RB26 series engines.
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AxiOn419
Posts: 262
Joined: Mon Sep 12, 2005 5:52 pm
Car: 1991 240sx SE Super-Hicas w/ RB20DET
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Hey guys,

I've just about got my Quest alternator mounted and ready to go. Just waiting for the heim joint tensioner to arrive.

Since this car has sat for so long and had charging issues in the past, I am a bit paranoid about the wiring of the alternator, specifically the red/white wire on the actual plug that plugs directly into the alternator. It is my understand that this is for the battery light on the gauge cluster and it is an integral part of the alternator functioning properly. Does the red/white wire on the alternator run directly to the gauge cluster? Yesterday I checked for continuity between the red/white wire on the alternator plug and the red/white wire on the gauge cluster plug (pictures below). My multimeter didn't emit a sound which means no continuity (but it did display a really high number, 1770). Is this a proper way to test this?? Should there be continuity between these 2 points? The battery was fully disconnected, not that that should matter.

I also read that a 12v light can be wired directly to the red/white wire in order to bypass the gauge cluster, if needed.

I checked for continuity by probing both of the wires next to the pink arrow in these pictures:

Alternator plug: Image

Gauge cluster plug: Image

Any help on this specific topic is greatly appreciated.


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AxiOn419
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:gotme

Bump, any advice would be helpful

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HxC_Nismo
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Car: 98' Nissan 240sx SE R33 RB26DET, 07' Nissan Titan SE, 05' Toyota Corolla
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sorry double post
Last edited by HxC_Nismo on Wed May 20, 2015 12:09 pm, edited 1 time in total.

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HxC_Nismo
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Car: 98' Nissan 240sx SE R33 RB26DET, 07' Nissan Titan SE, 05' Toyota Corolla
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did you unplug the plug on back of the cluster before you did your continuity test on the wire? I just plugged mine straight in and it works just as it did before.

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AxiOn419
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Car: 1991 240sx SE Super-Hicas w/ RB20DET
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HxC_Nismo wrote:did you unplug the plug on back of the cluster before you did your continuity test on the wire? I just plugged mine straight in and it works just as it did before.
I believe I tested mine while it was still plugged into the gauge cluster. Does it matter if it is plugged in or not when testing? The alternator plug was not plugged into the alternator when testing.

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Carl H
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Car: 1995 240SX SE RB30DET

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assuming the wire is in good shape you should have very low resistance across the wire.
if you were testing across the bulb then the resistance will be significantly higher.


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