Battery dummy light function with CTS-V LS2
05-10-2016, 02:30 PM
#1
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Battery dummy light function with CTS-V LS2 Hi, I'm swapping a LS2 from a '07 CTS-V using the LS2 controller kit from GMPP in my Nissan S12
I can tell I'm going to have an issue with the dummy ''low charge'' light in the dash. On the S12, there is a switched ground coming out from the alternator.
When the alternator isn't charging, the wire is grounded, as soon the alternator give the correct voltage, the ground open.
This ground act on a relay that control the bulb check (key on, engine not running, all warning lights are on) and the low charging indicator bulb.
My question is, is there a such wire on the CTS-V alternator connector? I doubt so but I could be lucky.
If not, maybe I could use another wire that get 12V from the alternator when it is charging but that wouldn't be connected to the battery when the car is stopped (to avoid draining the battery when the car is stopped). Is there a such wire? If so I could use it to drive a relay and i'll figure out the rest of the wiring from there.
And before anyone suggest to just remove the bulb, it's a requirement to have them all working for the inspection.
Cheers!
I can tell I'm going to have an issue with the dummy ''low charge'' light in the dash. On the S12, there is a switched ground coming out from the alternator.
When the alternator isn't charging, the wire is grounded, as soon the alternator give the correct voltage, the ground open.
This ground act on a relay that control the bulb check (key on, engine not running, all warning lights are on) and the low charging indicator bulb.
My question is, is there a such wire on the CTS-V alternator connector? I doubt so but I could be lucky.
If not, maybe I could use another wire that get 12V from the alternator when it is charging but that wouldn't be connected to the battery when the car is stopped (to avoid draining the battery when the car is stopped). Is there a such wire? If so I could use it to drive a relay and i'll figure out the rest of the wiring from there.
And before anyone suggest to just remove the bulb, it's a requirement to have them all working for the inspection.
Cheers!
05-10-2016, 10:02 PM
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Yes E67
I found a full pinout diagram in the instruction for their crate engines using de E67.
On the grey plug (C3) there is:
Pin#7 Orange Wire - Generator Pos B
^I'm guessing that's the field current to the alternator
That's the only pin that I can see is related to the alternator.
I found a full pinout diagram in the instruction for their crate engines using de E67.
On the grey plug (C3) there is:
Pin#7 Orange Wire - Generator Pos B
^I'm guessing that's the field current to the alternator
That's the only pin that I can see is related to the alternator.
05-10-2016, 10:46 PM
#5
I've never tried it, but I would suspect you could probably wire in a low voltage disconnect to a relay to turn the light on when the voltage drops below a specified level. Wouldn't be 100% factory but should work for a dummy light. They are cheap on ebay. Just a thought.
05-10-2016, 10:57 PM
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I've never tried it, but I would suspect you could probably wire in a low voltage disconnect to a relay to turn the light on when the voltage drops below a specified level. Wouldn't be 100% factory but should work for a dummy light. They are cheap on ebay. Just a thought.
I've looked a bit and didn't find anything like that.. do you got a link to ebay for an example of what you are talking about? That'll be appreciated.
Also, after reading a bunch of builds with similar issue (people trying to tap in a dummy light or resistor to their factory alternator wiring) it gave me an other idea. I thought that maybe I could use the generator signal (L) to drive a relay... I wonder if this could harm the alternator.
So mainly tapping in the ''L'' wire a parallel circuit with a relay. Now I need to know if this could affect the signal of the L wire (shouldn't if it's in parallel... but I'll like to make sure) and if the L really get voltage only when the alternator is charging.
*EDIT* Something like this ls1nova71?
http://www.ebay.ca/itm/Low-Voltage-D...kAAOSwf-VWUYzF
So I could set it to disconnect at 12.1V and reconnect at 12.8V... but at 12.1V it means that instead to connecting it directly to the battery I'll have to connect it to a power source powered with the key at ON/START only... Sound like a solid idea so far!
Last edited by Djays12; 05-10-2016 at 11:09 PM.
05-11-2016, 10:20 PM
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So after some research it seem that I was looking for a complicated solution to a simple problems.
http://www.bimmerforums.com/forum/sh...ternator-light
If I get it right, the L post on the alternator goes ground when the alternator is not charging. As soon the alternator is charging, the L post output 12V.
In my case, when the alternator is not charging, the ground it create activate the relay. When the alternator charge, it output 12V... there is a diode inline with my OEM wire before the relay... so the 12V cannot go back to the relay... So it means I can just tap this wire to the LS2 L pin... most people use a 470ohm resistor or a bulb. Apparently feeding 12V directly shorten the alternator life dramatically.
In my case the power will go from a switched 12V+ to the dummy lamp then split to the check bulb relay or the diode...the diode wire goes to the alternator L post.
I'll try that is it is the most simple way to do it and the least expensive (unless I'm wrong and crap the alternator haha)
*EDIT* In case someone stumble on this thread and also wondered how to wire their LS alternator. This link explain a lot about alternator, and what wire serve which purpose and how the computer relate to the alternator. It was an interesting read.
http://www.diagnosticnews.com/are-yo...arging-system/
http://www.bimmerforums.com/forum/sh...ternator-light
If I get it right, the L post on the alternator goes ground when the alternator is not charging. As soon the alternator is charging, the L post output 12V.
In my case, when the alternator is not charging, the ground it create activate the relay. When the alternator charge, it output 12V... there is a diode inline with my OEM wire before the relay... so the 12V cannot go back to the relay... So it means I can just tap this wire to the LS2 L pin... most people use a 470ohm resistor or a bulb. Apparently feeding 12V directly shorten the alternator life dramatically.
In my case the power will go from a switched 12V+ to the dummy lamp then split to the check bulb relay or the diode...the diode wire goes to the alternator L post.
I'll try that is it is the most simple way to do it and the least expensive (unless I'm wrong and crap the alternator haha)
*EDIT* In case someone stumble on this thread and also wondered how to wire their LS alternator. This link explain a lot about alternator, and what wire serve which purpose and how the computer relate to the alternator. It was an interesting read.
http://www.diagnosticnews.com/are-yo...arging-system/
Last edited by Djays12; 05-12-2016 at 10:54 PM.