battery draw, S13 rb25det

Discuss the RB20, RB25 and RB26 series engines.
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RB_Seth
Posts: 152
Joined: Sun Jan 07, 2007 10:39 am
Car: 92 240sx RB25
91 240sx LT1
95 240sx 280k mile DD

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I have a battery draw on my 92 hatch, series 1 rb25det. I found that when i unplug the one blue relay in the engine harness near the ecu (one with thicker black/red, red, orange, and white wires i believe) that my draw goes away. I was searching on here and found the one thread about the red ecu light staying on, but my led in the ecu turns off when i turn the key off. I had the wiring done by McKinney, at the time the motor was going into an 89 so i sent them a sohc harness and not a dohc. i just changed pins around for the dash connector to make it work in this car... Anyone have any ideas before i try cutting the one orange wire? Thanks


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RB_Seth
Posts: 152
Joined: Sun Jan 07, 2007 10:39 am
Car: 92 240sx RB25
91 240sx LT1
95 240sx 280k mile DD

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The relay by the ecu that is Pin 1 - orange, Pin 2 - red, Pin 3 - black/red, Pin 5 - whiteThe computer turns on with this relay unplugged so I would guess that makes this the ignition relay and not the ECCS relay. I checked the codes to make sure the led on the computer works and it flashed code 55. The led does go off with the key. Amp draw with this relay unplugged is .016amp, plugged in it is .118amp, I checked on another known good (and completely stock) 240 and it has a .010amp draw.

Key off, relay unplugged:Pin 1 - 0vPin 2 - 12.5vPin3 - 0vPin5 - 0v

Key off, relay installed:Pin 1 - 5.1vPin2 - 12.5vPin3 - 1.3vPin 5 - 1.3v

Key on (start position) relay installed:Pin 1 - 1vPin 2 - 12.2vPin 3 - 12vPin 5 - 12v

Key on (acc. Position) relay installed:Pin 1 - 4.9vPin 2 - 12.3vPin 3 - 1.3vPin 5 - 1.3v


Joe
Posts: 6511
Joined: Sun Feb 09, 2003 8:29 pm
Location: Phoenix, AZ

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1 volt and 5 volts sounds like a backfeed or a crossed wire to the relay. trace the wire to any switches sources (key) and find out whats going on. just follow them back, disconnect connectors till you find one that stays hot.

edit: im overthinking this, replace the relay with another one. the relay might be bad.

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RB_Seth
Posts: 152
Joined: Sun Jan 07, 2007 10:39 am
Car: 92 240sx RB25
91 240sx LT1
95 240sx 280k mile DD

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i swapped in a few different relays that i just got from a friend. They all click as soon as i plug them in... What activates this relay? Pin 2, the red wire that is always hot goes into the engine bay i think, i'll try following it more.

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Kansei240sx
Posts: 1356
Joined: Mon Nov 01, 2004 10:17 am
Car: S13 - RB25 Circuit car
71 240z - street/track day car
AE86 - Daily Drizzle/track day car
Z31t - Paper weight/street car
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Check your ignition relay ACC 2 in the engine bay. Chances are that relay was overloaded and the two wires got so hot the insulation melted causing that to circuit to stay hot as long as there is a relay plugged in all the time.

Also check the (6 pin?) white/clear connector under the dash that runs to the key cylinder for the ignition.

From what it sounds like, you're going to need to take that fuse box apart thats normally by the factory air box and look at the wires from below.


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