Alternator Wiring Testing

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benckj
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Re: Alternator Wiring Testing

Post by benckj » 09/09/19 5:17

Some progress over the weekend although not as much as I would have liked due to poor weather on Sunday.

Managed to get the new parts installed into the turbo alternator and button it up. Car fired up on first pop and monitoring voltage at idle was only around 12.8. After reving slightly it jumped to 14.5 and stayed between this & 14.8 regardless of RPM. Still want to run a data log while under load and make sure its dead steady before I'm happy. Battery will need a good charge before idle voltage is steady.

Will get to NA soon enough. I'm certain the alternator is repaired as it was test run a sparky shop. I have more room to work on NA but as bracket was removed need to install this first. Shouldn't be an issue just time I don't have at the moment.

I'll be severely disappointed if I only get 6-8 months out of them. They both have a life time guarantee although I would think it must be returned to US. Where do you get the Denso Regulators & rectifiers from?



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benckj
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Location: Alexandra, New Zealand

Re: Alternator Wiring Testing

Post by benckj » 16/09/19 0:06

NA alternator installed & tested. Stationary runs at approx 14.5v regardless of RPM. Problem was rectifier and I replaced with the one which was on my turbo.

Turbo is better than before but still not very stable during a 20m road run. At idle its drops to approx. 11.8v and after around 1000RPM runs between 14.2 and 15v. I need to snip a bit of the datalog and place here for comment.

Maybe I'm getting fussy but thought it should be better than this. Could possibly have something else noisy with car on the load side as I run multiple pumps & motors (A2W, WI, PS, fans, etc). Alternator still makes a 'whirrling' noise when running. Have confirmed brushes & slip rings OK and it rotates fine by hand with no obvious obstruction or resistance.

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MR2DI4
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Re: Alternator Wiring Testing

Post by MR2DI4 » 16/09/19 7:12

Voltage should be dead stable on 14.6V regardless of everything else as long as the battery is not dead flat, even then it should come up pretty quick.

Unlike a modern car there appears to be no "Smarts" in the alternator charge Voltage. My 2005 Subaru Voltmeter is all over the place, it kicks in at over 14V but depending on rpm's and whats turned on in the car it can drop to 13.8V or I have seen it drop right off even lower for brief periods.

I would say you still have a problem with the Turbo alternator. No Voltmeter in my MR2 but the fuel pressure gauge at idle gives you a rough idea of whats going on.It used to be all over the place now its as stable as.

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benckj
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Re: Alternator Wiring Testing

Post by benckj » 16/09/19 21:34

I tend to agree with you and would like to find the issue. Can probably survive as is because it does work and I need to have operational for a few trips coming up. Road trip & ttTrack day in Nov which I'm hoping to make if I can get my boost spikes under control.

I'll snip a few bits of the datalog which show voltage, rpm, duty cycle, MAP, etc and see if any ideas come to mind. May simply turn into a grounding issue with my alternator, EMS or something similar like unbalanced load on circuit. Don't know so I'm open to ideas.

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