Starter failing, battery meter pegged?

[Yarb]

Need to dig around to find where that goes. Should be easy to find being red. Most professional audio companies use yellow 12 gauge wire for direct 12V supply to a bridge.

[Patcon]

@SteveJ

If the starter doesn't disengage would it add current to the system?

[Zed Head]

There was a whole long thread a couple of years ago about this car.  A swap to an internally regulated alternator, with a jumpered plug.  I got confused just re-reading my own comments in the thread.  Not sure I was helping.  

It ended with "new battery".   Not so sure now...

 

[RJK]

2 hours ago, SteveJ said:

13.2 V @ 2000 RPM is not good. As suggested earlier, contemplate replacing your voltage regulator.

The red wire is not original to the car. You might want to see where that wire goes to. Someone may have "fixed" something only to cause other problems.

Thanks. At the time I replaced the alternator(maybe it was earlier than last fall? Post-Covid all time calculation is a bit of a blur for me), I recall being advised to use a jumper in place of a voltage regulator, which is in the car now. Maybe this is the source of the problem? I just ordered a voltage regulator and a new starter motor from Z Car Depot. I will investigate the termination point of the red wire at the starter motor as well. Thanks folks!

[cgsheen1]

Okay, I'll readily admit that I didn't read every post in this thread with great care BUT: The insulation on the wire between the solenoid and the starter motor should NOT be burned to he!!... AND, looking at the bottom terminal on the solenoid, that nut and stud look to me like they have both overheated to an alarming degree! At a minimum you need to remove that wire from the solenoid and check everything for oxidation. I would also remove the charred insulation and check the wire inside. (And, if it were me, I'd probably not use that starter...) Just my opinion.

[Zed Head]

9 minutes ago, cgsheen1 said:

The insulation on the wire between the solenoid and the starter motor should NOT be burned to he!!... 

I saw that too.  I wondered if the starter motor was getting stuck on.  

[Yarb]

I tell ya if I had to do it all over again and had a factory starter/alternator that went south I’d definitely look for someone to rebuild it. The quality we are getting these days is beyond questionable.

Edited September 28, 2023 by Yarb

[Zed Head]

50 minutes ago, RJK said:

I just ordered a voltage regulator

If I understood your first alternator wiring thread you have swapped in an internally regulated alternator.  Linked below.  But, there's no guarantee that it has not failed.

Might be worthwhile to take it in to a parts store and have it tested.

https://zcardepot.com/collections/charging-starting/products/alternator-high-amp-80-240z-260z-280z?variant=19280584015985

 This alternator is rated at 70 amps and bolts up in the same location as the original. Internally regulated.

[SteveJ]

9 hours ago, Patcon said:

@SteveJ

If the starter doesn't disengage would it add current to the system?

Yep, and it would make a lot of noise, too.

[SteveJ]

7 hours ago, Zed Head said:

If I understood your first alternator wiring thread you have swapped in an internally regulated alternator.  Linked below.  But, there's no guarantee that it has not failed.

Might be worthwhile to take it in to a parts store and have it tested.

https://zcardepot.com/collections/charging-starting/products/alternator-high-amp-80-240z-260z-280z?variant=19280584015985

 This alternator is rated at 70 amps and bolts up in the same location as the original. Internally regulated.

@RJK Do this. There is a voltage regulator integral to the alternator if you went for an internally regulated alternator. I have done Frontier alternator swaps on several Z cars now because I don't have a lot of faith in rebuilt alternators. The only time I saw a Frontier alternator swap with issues was when someone went with a rebuilt Frontier alternator. (Imagine that.) He bought the alternator I suggested, and his problems stopped.

[RJK]

Yea, that charring of the insulation definitely concerned me, hence the nature of my post.

 

This may be a daft question to ask, but what happens if I connect a voltage regulator to an internally regulated alternator? Does it just function as a redundancy?

 

Also, is there a "known quantity" starter and alternator available on the market? I vaguely recall there being talk of rebuilding a 280z alternator with modifications, but I found it confusing...

 

@SteveJ what is a Frontier alternator? I am googling and not finding it, if it's a brand name. Also, you said "13.2V at 2k RPM is not good"-safe to assume I should be seeing HIGHER than that, correct? My 928 probably runs 13.8 or so at ~2k.

 

THANKS for all the help folks! I don't know if a poorly regulated alternator could result in the starter failing, but it does appear to be that this starter has crapped the bed after a very short lifespan. I generally assume "user error" on my part, but maybe the part itself has failed. Nevertheless, no driving til I figure this out.

[SteveJ]

3 hours ago, RJK said:

This may be a daft question to ask, but what happens if I connect a voltage regulator to an internally regulated alternator? Does it just function as a redundancy?

Bad things happen. The alternator won't be getting a battery sense line, so it will crank up the voltage.

3 hours ago, RJK said:

Also, is there a "known quantity" starter and alternator available on the market? I vaguely recall there being talk of rebuilding a 280z alternator with modifications, but I found it confusing...

 

@SteveJ what is a Frontier alternator? I am googling and not finding it, if it's a brand name. Also, you said "13.2V at 2k RPM is not good"-safe to assume I should be seeing HIGHER than that, correct? My 928 probably runs 13.8 or so at ~2k.

Starters? I'm not sure about. Frontier refers to Nissan Frontier (from 2004 or earlier). The alternator from the 2.4L version will fit on the Z mounting bracket, and the pulley works with the fan belt. It's not exactly a drop in replacement, but you can get "new" alternators for the Frontier instead of a remanufactured one. You also have to buy a connector to fit the alternator and add a 2-pin connector to that in order to plug into the engine harness. 

In a properly functioning electrical system, the voltage should be between 13.5 and 14.5 volts with the car running. A bad alternator, voltage regulator, or battery will affect the voltage. I use a clamp DC ammeter along with my multimeter to tell me if it's the charging system or battery. A low voltage and no current output from the alternator says bad charging system. A low voltage and several amps of current tell me it's the battery.

3 hours ago, RJK said:

THANKS for all the help folks! I don't know if a poorly regulated alternator could result in the starter failing, but it does appear to be that this starter has crapped the bed after a very short lifespan. I generally assume "user error" on my part, but maybe the part itself has failed. Nevertheless, no driving til I figure this out.

The alternator would not cause issues with your starter. The damaged insulation on the conductor between the solenoid and starter indicates that the starter is pulling too much current. The current source would be the battery since the engine isn't turning the alternator at a speed to generate much power during starting. It could indicate insulation failure in the windings of the starter motor.