1998 s70 p0563 System voltage high

Post by **BEJinFbk** » 17 May 2015, 11:48

Are you pricing a REAL Volvo alternator or a rebuild?
If you still have an actual stock alternator, keep it.
Rebuilds are notoriously crappy.

And shop a little harder for a new regulator.
$140 seems high.

Post by **misha** » 17 May 2015, 15:17

I think they were around 80$ at FCP.

Post by **abscate** » 18 May 2015, 08:47

cjbmustang wrote:it's been off for like 5-8 years...doubt it would randomly start causing me problems now. For ha ha's I will ground it. It sounds like the voltage regulator to me...just looking for opinions

Loose electrical connections will do exactly that. Rear their ugly heads suddenly - usually at the T5 tornado is coming down on you.

Running an alternator ungrounded will fry it up quickly, so once your bad ground decides to give you grief, you have to shut it off immediately.

16 V will take out your battery, ECU and a lot more $tuff

cjbmustang · Post by **cjbmustang** » 18 May 2015, 17:34

Correct me if I'm wrong, but doesn't the battery get grounded to the block and also the chassis?

I ordered a new regulator for $40 and also a new water temp sensor, as it was leaking down the wires and onto the alternator.

the alternator is a bosch 100amp

Thanks,

Chris

Post by **misha** » 18 May 2015, 17:49

On these cars Yes.
Alternator is grounded via it's housing which is bolted onto engine.The only wires which are connected to alternator is thick red B+ and a tiny one for light on the dash.
But....you would need negative cable from a battery to be connected to engine and chasis and you have one of them disconnected for a loooong time.It is necessary for proper function of alternator,otherwise it's will be fryed.

Post by **abscate** » 18 May 2015, 20:08

Many, many people here have reported bad electrical problems due to bad grounds, wires, connections.

Post by **BEJinFbk** » 18 May 2015, 20:17

I would offer a different point of view about this issue.

The regulator is built into and grounded to the alternator.
If the coils, diodes and regulator are all working, as long
as it spins fast enough, the correct range of voltage will be
produced regardless of any other grounding in the vehicle.

What I mean is, if it's running OVER voltage, as described,
it's almost a certainty that the regulator is the point of failure.

In older cars with outboard regulators, sure - Ground is Critical.
But in cars with the regulator built into the alternator, it's pretty
much a stand alone, self-regulating 12 volt supply.

draser · Post by **draser** » 19 May 2015, 06:12

This is correct providing the ground connection of regulator is working (not corroded, etc). At any rate the regulator needs removed and inspected, if ground ear is okay then new reg is needed.

cjbmustang · Post by **cjbmustang** » 19 May 2015, 06:46

Thank you. These were my thoughts as well. I will repair the ground but did not think it was the root cause.

draser · Post by **draser** » 19 May 2015, 08:50

This is the ground terminal of the regulator itself, inside the alternator. There's an ear there that gets connected to alt case by a screw. If that is corroded it'll provide a so called floating ground and output will go high. Same symptom if regulator is shorted input to output or leaky. I'll remove reg cover, then regulator and examine regulator terminals or contact points. If the ground ear is clean and lands on a clean surface on alt case then your reg is bad.

1998 s70 p0563 System voltage high

Re: 1998 s70 p0563 System voltage high