BMW K bikes (Bricks)

You are not connected. Please login or register

View previous topic View next topic Go down  Message [Page 1 of 1]


1Back to top Go down   16.7v from the Alternator Empty 16.7v from the Alternator on Mon Aug 17, 2015 5:21 am

rapt

rapt
active member
active member
So  I have just re-assembled my K100 after stripping it down and got it started up after 6 months of being apart. 

I was looking in to running a Lithium battery so I though I would check the Voltage. 

The Charge voltage is sitting at 16.7v. This is much too high to run a lithium battery and more than likely too high for the rest of the bike. 
I confirmed my meter was not wrong by checking it on a battery charger that was 13v.

Any ideas what could be causing this?

    

2Back to top Go down   16.7v from the Alternator Empty Re: 16.7v from the Alternator on Mon Aug 17, 2015 5:41 am

Dai

Dai
Life time member
Life time member
Almost certainly a faulty regulator. However, before definately fingering the reg,

1.Check the alternator bulb on the dashpanel lights - it does light when you turn the ignition key on?
2. Before starting the bike, check that you have twelve-ish volts on the blue wire that connects to the top of the alternator (probably a redundant check because if the genny bulb is blown then there shouldn't be any voltage but... you could have a short circuit.
3. If 1 and 2 fail, pull the alternator and check the brushes for length or for being stuck in the housing.


__________________________________________________
'83 K100 upgraded to K100RS spec
Others...
'78 Moto Guzzi 850-T3, '79 Moto Guzzi 850-T3 California,'93 Moto Guzzi 1100ie California,
'03 Suzuki Blandit GSF600SK3 (NFS any more because wifey has claimed it)
    

3Back to top Go down   16.7v from the Alternator Empty Re: 16.7v from the Alternator on Mon Aug 17, 2015 5:55 am

92KK 84WW Olaf

92KK 84WW Olaf
Life time member
Life time member
Dai

Spot on.

We had a discussion on that subject yesterday, being with some Honda owners. They fingered the effect of a faulty regulator in alternators like the BMW one as being exactly that, excess voltage.


__________________________________________________
1992 K100LT 0193214 Bertha Alaska Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 58,645 now 96,650 miles
1983 K100RS 0011175 Fricka 29,495 miles Damn K Pox Its a Bat outta Hell
    

4Back to top Go down   16.7v from the Alternator Empty Re: 16.7v from the Alternator on Mon Aug 17, 2015 6:14 am

rapt

rapt
active member
active member
@Dai wrote:Almost certainly a faulty regulator. However, before definately fingering the reg,

1.Check the alternator bulb on the dashpanel lights - it does light when you turn the ignition key on?
2. Before starting the bike, check that you have twelve-ish volts on the blue wire that connects to the top of the alternator (probably a redundant check because if the genny bulb is blown then there shouldn't be any voltage but... you could have a short circuit.
3. If 1 and 2 fail, pull the alternator and check the brushes for length or for being stuck in the housing.


The gene bulb is either blown or has been knocked and there is no voltage on the blue wire with the ignition on and the bulb is not lit.

I relocated the bulb it to the inside of the fuse box so it lights up the fuse cover after I installed an acewell speedo when I first got the bike. I will remove the tank to check it tomorrow as it was working earlier on today before I started the bike.

Could a blown genny bulb cause the high voltage? From what I read it would mean the charge circuit would not kick in on most bikes.
I will also check the brushes tomorrow.

    

5Back to top Go down   16.7v from the Alternator Empty Re: 16.7v from the Alternator on Mon Aug 17, 2015 7:08 am

Dai

Dai
Life time member
Life time member
Got it in one. A blown genny bulb will cause the high voltage because the regulator will never kick in.


__________________________________________________
'83 K100 upgraded to K100RS spec
Others...
'78 Moto Guzzi 850-T3, '79 Moto Guzzi 850-T3 California,'93 Moto Guzzi 1100ie California,
'03 Suzuki Blandit GSF600SK3 (NFS any more because wifey has claimed it)
    

6Back to top Go down   16.7v from the Alternator Empty Re: 16.7v from the Alternator on Mon Aug 17, 2015 7:55 am

92KK 84WW Olaf

92KK 84WW Olaf
Life time member
Life time member
That's worth a Black Bush.....! For Dai.

Now wondering when will we get our first forum member visitor from NZ..


__________________________________________________
1992 K100LT 0193214 Bertha Alaska Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 58,645 now 96,650 miles
1983 K100RS 0011175 Fricka 29,495 miles Damn K Pox Its a Bat outta Hell
    

7Back to top Go down   16.7v from the Alternator Empty Re: 16.7v from the Alternator on Mon Aug 17, 2015 9:22 am

Dai

Dai
Life time member
Life time member
Easy Very Happy Over-voltage = regulator, under-voltage = rectifier. Well, most of the time!


__________________________________________________
'83 K100 upgraded to K100RS spec
Others...
'78 Moto Guzzi 850-T3, '79 Moto Guzzi 850-T3 California,'93 Moto Guzzi 1100ie California,
'03 Suzuki Blandit GSF600SK3 (NFS any more because wifey has claimed it)
    

View previous topic View next topic Back to top  Message [Page 1 of 1]

Permissions in this forum:
You cannot reply to topics in this forum