S14 Alternator charging problem

[kingJurzy]

This isn't your average disconnected wires or fuse.


I've checked on my s14:
the 75amp fuse in the fuse box in the engine bay
ive checked the alternator ground
ive checked the power wire connected to the alternator
ive jumped the pins inside the cluster that complete the alternator signal to charge the battery (pins 14 to 20)


I'm using a volt meter to check voltage everywhere.

My battery has been relocated to the back for a while now and one day my car died while driving due to the alternator not charging the battery. I've checked above and im stumped.

Please help.

[S-Nation S13]

Have you tested the alternator itself? my s13 alternator did this to me changed out the alternator and fixed problem. start there

[kingJurzy]

Sorry, forgot to add the alternator was tested 3 times and passed every single time.

[Agamemnon]

Have you checked the continuity between the alternator and the pin behind the cluster?

[kingJurzy]

And what if that continuity is bad?

[SidewaysS13ka]

hey dude a similar problem happened to my buddies rb coupe with the alternator not charging the battery, but what was wrong was the big square plug on the alternator was shaking loose off the alt from the stiffness and the cold side pipe vibrating on the alt, needless to say i pushed that connector in and it fired up. check that plug on top of the alt and see if the clip is broken or if its loose after you take it for a ride. just a thought.

[kingJurzy]

Thanks,

I've plugged the pigtail in the ALT all the way to the point where it clicks still no charge. Im just stumped because everything that should be in order is there and accounted for.

[SidewaysS13ka]

Thanks,

I've plugged the pigtail in the ALT all the way to the point where it clicks still no charge. Im just stumped because everything that should be in order is there and accounted for.

is your lower harness fried?

[dbeiler]

You really shouldn't be jumping any pins in the gauge cluster. Are you referring to the charge light pins? That would be pins 15 and 21, not 14 and 20.

A wire jumper does not take the place of a light bulb. If you jump those pins, you are directly grounding out that circuit via the alternator ground. You will blow a fuse or fry something.

For the alternator to function, it must have:

A power wire to Terminal 1, to flow output power produced by the alt, which you've already checked.

A good ground to Terminal 2, which you've already checked.

A small W/R wire to Terminal 3. This wire is grounded by the alt to illuminate the charge warning light. If you jumper this wire in the gauge cluster, you are directly grounding out the circuit via the alt. This charge warning circuit must be functioning for the alt to charge. Install the proper bulb and check the fuse for bulb power. I believe that is a 7.5amp fuse labeled as "gauges" or EL power" in the driver's footwell fuse box.

A small power feed wire to Terminal 4, this is connected to the fuse box, and is used to supply battery voltage to the alternator IC regulator. The alt monitors this wire voltage to decide if it needs to be charging the battery.

[Mister.E]

A small W/R wire to Terminal 3. This wire is grounded by the alt to illuminate the charge warning light. If you jumper this wire in the gauge cluster, you are directly grounding out the circuit via the alt. This charge warning circuit must be functioning for the alt to charge. Install the proper bulb and check the fuse for bulb power. I believe that is a 7.5amp fuse labeled as "gauges" or EL power" in the driver's footwell fuse box.

If completely bypassing the bulb, how would one go about hooking this wire back up? Would it get wired directly to a 7.5A BAT power fuse or a 7.5 ACC power source?

I was trying to get an answer for this elsewhere but no luck...

https://zilvia.net/f/showpost.php?p=6374823&postcount=23085

[Mister.E]

So i went back to the FSM with all the info I’ve received recently and it looks like that wire went back to an IGN source.

My question now is, when bypassing the bulb and running it straight to the 7.5A IGN source, do I need to put a resistor inline to compensate for the bulb?

What do the guys that switch to aftermarket gauge clusters do with this wire?

https://uploads.tapatalk-cdn.com/20200316/d81d441ca2b974b4914e14469f364bb0.jpg


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[dportd]

Sounds like terminal 3 is simply a ground wire coming from the alternator for the bulb circuit and to ground out the internal regulator.

I would imagine if you aren't running the bulb then this wire can be connected to a solid ground instead of "jumping" it.

Not 100% on that but just what it sounds like to me.

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