Page 1 of 1

Ka24de alternator charge light help

Posted: Tue Feb 14, 2017 7:53 pm
by npa4863
On the s14 ka24de (obd2) the charge light needs to be hooked up for the alternator to produce the correct voltage. After some research i found that theres a resistor in the cluster parallel with the charge light. Can some one ohm the charge lamp circuit in the cluster? Or if you know the correct resistor to delete the light?


[img width=768 height=1024]http://i949.photobucket.com/albums/ad336/npa4863/Mobile%20Uploads/20170214_131424.jpg[/img]

Re: Ka24de alternator charge light help

Posted: Sat Aug 21, 2021 11:26 pm
by R34SR
Years later, I'm in this same boat and I need the answer to this...

Re: Ka24de alternator charge light help

Posted: Sun Aug 22, 2021 7:44 am
by modulation

Re: Ka24de alternator charge light help

Posted: Sun Aug 22, 2021 7:57 am
by modulation
I'd try like a 470ohm 1/2 watt resistor. Measure the voltage while charging and go with more ohms if voltage is too high.

Re: Ka24de alternator charge light help

Posted: Sun Aug 22, 2021 8:09 am
by modulation

Re: Ka24de alternator charge light help

Posted: Sun Aug 22, 2021 6:38 pm
by R34SR
Appreciates, saw the 510 one and figured that's where I'll start.

Re: Ka24de alternator charge light help

Posted: Tue Aug 31, 2021 7:14 pm
by p00t
I had no idea about the resistor in parallel with the bulb. Interesting.

But the alternator finds it's voltage on the sense line that is connected to the battery. The alternator should just be using the bulb for diagnostics. It is possible the resistor plays a part in whether the bulb accurately lights (to prevent a false indication of a problem).

Is your alternator voltage wacky or okay? Have you tried a different alternator?
s14_alt.GIF
s14_alt.GIF (8.75 KiB) Viewed 3643 times

Re: Ka24de alternator charge light help

Posted: Tue Aug 31, 2021 7:45 pm
by p00t
So the plot thickens sort of...

I checked out an s13 due to curiosity...

The same thing is happening except instead of a resistor in the cluster it uses the bulb check relay coil. Hmm.

So the current through the bulb/resistor is just enough to turn the circuits on inside the alternator.

100 ohm resistor sounds rights that is close to a relay... or use a relay!?

Re: Ka24de alternator charge light help

Posted: Wed Sep 01, 2021 6:16 am
by R34SR
Well I wired it up with the charge light to ignition power, and the other line Direct to the alternator + stud...so far all seems well.inram completely new lines since I have aftermarket gauge cluster. Appreciate the insight though, and if it fails again I'll try the resistor.

Re: Ka24de alternator charge light help

Posted: Sun Dec 19, 2021 8:01 pm
by R34SR
Thought I'd share, the alternator and voltage seemed fine for all of 45 MI s of driving then the voltages started to read high 14.9 to 15v....then it just stopped charging all together, ilet the car cool for 30 mins... And everything went back to normal... Seems like once the car heats up the voyage regulator is not happy about something... Perhaps that resistor is needed after all... I'll. Get one and report back.

Re: Ka24de alternator charge light help

Posted: Sat Dec 25, 2021 4:55 pm
by tuzzio
I've never really understood this. I havent had a stock cluster / resistor in 5 years, and no issue.
I'm unsure if its cause I have a quest alternator, or a standalone, or an aftermarket cluster.
But my car is 14.2-14.4 always, and drops accordingly when the fans come on, or the blower motor. Same thing as my buddies 2J car.

Re: Ka24de alternator charge light help

Posted: Tue Dec 28, 2021 5:47 pm
by R34SR


Glad to finally put this topic to sleep.

470 ohm resistor so far has cured my issue since i replaced my factory cluster with a custom one.

Re: Ka24de alternator charge light help

Posted: Tue Jan 11, 2022 9:08 pm
by R34SR
So even though this worked, seems like i damaged the regulator from running without the resistor for too long....thats my current assumption...i cant believe how simple yet frustrating this charging system has been.