2000 4.2d Patrol failing alternator

[mvcoller]

I disagree with the notion that 13.4 v or 13.6v is sufficient. The minimum charge rate should be 13.8 v else you are not putting enough power back to get the battery up to 100%. Even that is low, if you are running a second battery, like a deep cycle battery, the charge rate MUST be 14.4 volts to get them both up to an acceptable level. A standard Bosch regulator is set to 14v these days.

I would say it is the and brushes that have reached the end on their reach, also maybe the regulator, but I doubt it would be the regulator. If it is a Bosch alternator, it is a piece of old takkie to put in new brushes and voltage regulator. It is a single unit that is held in place with two Phillips screws.

To replace it, undo the two phillips screws and fit a new voltage regulator. They cost peanuts really. Even if it is not this, it is a cheap enough option to try. To replace the regulator, there is no need to disconnect the positive lead on the battery to prevent a short, or to pull the big spade connector (main battery wire) off the alternator.

On the any regulator, you should see the output voltage that the regulator is set to printed on the back of the regulator. I find that FLAG regulators for Bosch alternators are best if you run a dual battery system, these are set to 14.4 volts. The one in the pictures here is set to 14v exactly. If you cannot get a FLAG, get one that delivers at least 14v, but the higher, up to 14.4 max, the better. Over 14.4 v you will start boiling your battery water and it will evaporate quite fast.

Bench charge your old battery at home with a decent charger (6 - 10 amps) for 24 hrs, take a reading, it should read at least 12,6 to 12.8 volts. Then take a reading 24 hrs later, and if it has dropped to 12.4 volts it is still OKish, but not quite 100%. If it is above 12.4 your battery is still good. The problem is then with the charging system. If 12.4v or below, and you at this stage, charge it with an intelligent 7 or 8 step charger for 48 or more hours, you can still recover it.

If after the first 24 hrs of rest, it has dropped to around 10.6v, there is a dead cell and you can write it off. Just get a new battery if that is the case.

1 The VR on the Bosch Alternator

VRegulator1 The VR on the Bosch Alternator.jpg (112.23 KiB) Viewed 4736 times

2 Undo the two screws

VRegulator2 Undo the two screws.jpg (109.59 KiB) Viewed 4736 times

3 Pull it out like this

VRegulator3 Pull it out like this.jpg (112.21 KiB) Viewed 4736 times

4 The actual regulator with the Voltage output printed on it

VRegulator4 The actual regulator with the Voltage output printed on it.jpg (106.79 KiB) Viewed 4736 times

5 Putting it back

VRegulator5 Putting it back.jpg (120.74 KiB) Viewed 4736 times

[ricster]

I agree with Malcolm, but the Patrols come with a Hitachi Alternator, and that is a bliksem to service as the regulator is inside the alternator. I have an aftermarket alternator ( I think 100 Amp) that uses the Bosch setup for the regulator. Its so simple to replace and dirt cheap as Malcolm said.

[Peter Connan]

Surely 14.4v will shorten the life of a crank battery? Which is the reason DC-DC chargers are so popular, because crank batteries need ideally to be run at less than 14v and deep cycles need more than that?

[Tinus lotz]

Surely 14.4v will shorten the life of a crank battery? Which is the reason DC-DC chargers are so popular, because crank batteries need ideally to be run at less than 14v and deep cycles need more than that?

Correct Piet
And they prefer 14.8v
At ideal situations they can charge 20% per hour exl heat losses and can be charged 300 times then they are scrap ....dc to dc is correct way forward....normal alternator must under load put 13.8 v out to service crank battery

[SCUBA Patrol]

Tinus,

dankie vir die inligting, iets wat ek amper nerens kon kry nie.

[EFH]

Het vandag die battery laat toets, is glo reg, net baaaie pap...

Gaan hom vir 2 dae laai soos voorgestel en dan maar die alternator uitruk en laat recon vir gemoeds rus onthalwe. Ek gaan ook die engine bay skoon skrop ne al die drade na die starter na gaan.

Dankie vir al die raad.

[ChristoSlang]

Good info on minimum voltages, gassing, cyclic vs. standby charging, etc. for lead acid batteries can be found here: https://www.powerstream.com/SLA.htm

[Kagiso II]

was vandag by Turbowroks -- Jean vertel my 'n omie klient van hulle het sy altyernator geneem vir herstel.Die skelm moere het die omie R2000 gecharge vir n "overhaul [maar NET die pulley vervang]
Juanne het toe die alternator na Turboworks se kontak gestuur .. KOMPLEET volledig oorgedoen vir R1400. ..
Stel voor jy kry die info by Turboworks en laat by hulle kontak jou alt oordoen

[EFH]

Ek sal wyd kyk, hier in Bloemfontein is daar baie scaly operators.

Moes so jaar of 2 terug Forester XT se alternator laat fix dealer wou R11000+ he vir replacement...

[EFH]

So, vinnge update:

Regulator en rectifier is beide gedaan en sal vervang moet word, dit saam met die diens van die borsels en bearings maak dit goedkoper en vervang met after market eenheid.

So, hier gaan ons...