S14 Alternator charging problem - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

kingJurzy · 05-30-2015, 02:42 PM

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 · 05-30-2015, 02:55 PM

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

kingJurzy · 05-30-2015, 03:07 PM

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

Agamemnon · 05-30-2015, 03:46 PM

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

kingJurzy · 05-30-2015, 06:15 PM

And what if that continuity is bad?

SidewaysS13ka · 05-30-2015, 06:50 PM

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 · 05-30-2015, 07:03 PM

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 · 05-30-2015, 07:39 PM

Quote:

Originally Posted by 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.

is your lower harness fried?

dbeiler · 05-30-2015, 09:27 PM

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 · 03-15-2020, 08:15 PM

Quote:

Originally Posted by dbeiler

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=...ostcount=23085

Mister.E · 03-15-2020, 10:19 PM

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?

Sent from my iPhone using Tapatalk

dportd · 03-16-2020, 05:54 AM

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.

Sent from my Pixel using Tapatalk

05-30-2015, 02:42 PM	#1
kingJurzy Zilvia Member Join Date: Jun 2014 Location: SF bay area Posts: 181 Trader Rating: (3) Feedback Score: 3 reviews	S14 Alternator charging problem 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.

05-30-2015, 06:50 PM	#6
SidewaysS13ka Zilvia Junkie Join Date: Feb 2011 Location: Northeastern,PA Age: 34 Posts: 334 Trader Rating: (12) Feedback Score: 12 reviews	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. __________________ Leaks,Creeks,Squeaks, and other random problems. Yup you own a 240.

03-15-2020, 10:19 PM	#11
Mister.E Post Whore! Join Date: Oct 2007 Location: Las Vegas Age: 39 Posts: 4,590 Trader Rating: (53) Feedback Score: 53 reviews	S14 Alternator charging problem 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? Sent from my iPhone using Tapatalk __________________ : @e_lemonation

05-30-2015, 02:55 PM	#2
S-Nation S13 Post Whore! Join Date: Jan 2008 Location: LAND of the LOST Posts: 4,083 Trader Rating: (92) Feedback Score: 92 reviews	Have you tested the alternator itself? my s13 alternator did this to me changed out the alternator and fixed problem. start there

05-30-2015, 03:07 PM	#3
kingJurzy Zilvia Member Join Date: Jun 2014 Location: SF bay area Posts: 181 Trader Rating: (3) Feedback Score: 3 reviews	Sorry, forgot to add the alternator was tested 3 times and passed every single time.

05-30-2015, 03:46 PM	#4
Agamemnon Post Whore! Join Date: Sep 2003 Location: Lake Stevens, WA Age: 41 Posts: 2,657 Trader Rating: (20) Feedback Score: 20 reviews	Have you checked the continuity between the alternator and the pin behind the cluster?

05-30-2015, 06:15 PM	#5
kingJurzy Zilvia Member Join Date: Jun 2014 Location: SF bay area Posts: 181 Trader Rating: (3) Feedback Score: 3 reviews	And what if that continuity is bad?

05-30-2015, 07:03 PM	#7
kingJurzy Zilvia Member Join Date: Jun 2014 Location: SF bay area Posts: 181 Trader Rating: (3) Feedback Score: 3 reviews	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.

05-30-2015, 09:27 PM	#9
dbeiler Zilvia Junkie Join Date: Jun 2012 Location: Lancaster county, PA Age: 33 Posts: 465 Trader Rating: (4) Feedback Score: 4 reviews	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.

03-16-2020, 05:54 AM	#12
dportd Join Date: Jan 2020 Location: US Age: 34 Posts: 1 Trader Rating: (0) Feedback Score: 0 reviews	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. Sent from my Pixel using Tapatalk