BMW R1200R R1150R/T F800 K1200R R1100R/T R1250R RnineT Message Board

I have an '03 r1150r (I think this has the same set up as the GS), single spark, no abs, 30K miles.

It cranks over fast and starts right up.

When I turn the key to the on position the battery light and the neutral light do not come on, both stay off when the bike first starts but when you rev the engine both will light up.

Riding it yesterday, the battery light would would come on .

Oh, and the tach doesn't work. It will bounce a little but isn't accurate.

I lifted the tank, disconnected the plugs that I could get to, cleaned them and put a little grease on them.

I replaced the alternator belt. The old one looked fine.

With the key off it reads 12.5 volts across the battery terminal. Running it reads 11.5.

Any thoughts?

OK, a new 4 amp fuse fixed the charging and neutral light.

Any ideas on the tach?

I think the problems are related. What blew the fuse? It is not supposed to happen unless something is wrong. Very likely it is the same thing that's causing an intermittent connection to the tach. A break in those wires in the wiring harness loop that is physically traumatized when the steering is turned left or right. Damage is a certainty after several years if 2 factory installed zipties are not removed. Check your bike against THIS PIC.

Thanks Rob. The zip ties were still on. Is there a typical spot to find the damage?


After I replaced the fuse (4 amp, 1st one on the left) everything seemed normal except for the tach. I took it for a test ride and the same fuse blew again, neutral light stopped working and the charging light came on. I also noticed that the bike would start with the kickstand down and in gear. It would also turn over, in gear, without depressing the clutch.

After I cut the zip ties I cut the wiring harness as much as possible without removing the tank and couldn't find any obvious damage to the wiring.

Any and all suggestions and observations are appreciated.

Thanks.

rpd1,
The wire breaks would happen right at the ziptie band location, where it forces a flexing/moving sharp bend in the wire harnesses. Even though the wires "look OK" they can be broken off inside with no conductivity. You can tell by forcefully stretching 6" sections at a time to find 1 or 2 that stretch like the plastic insulation alone would do. Also possible is that protruding broken wire strands from adjacent wires are shorting together, giving weird goings on and blown fuses.

The fact the zipties where there doesn't mean that IS the problem, but it sure does fit the symptoms.

.

What would concern me the most is the 11.5v reading at the battery terminals with the motor
running. That is plainly incorrect and seems to indicate a fundamental problem with the
alternator/voltage regulator. I would think the voltage regulator is the main suspect. It's
where I would start. If the current rectifying section, which is probably a diode bridge,
has a faulty diode and excessive AC ripple is present this can cause other problems.
The first thing I would do is to find out why that voltage is as low as it is and not the 13/14v
it should be. Remember 13v to 14v should appear across the battery terminals irrespective
of whatever is switched on at the time (lights etc.). This will require the removal of the alternator
and getting it checked by a workshop. This has to be sorted out before the other fault may be dealt with.
Fr'instance: If the tacho circuitry in the instrument pod is protected by a 'reverse polarity' diode and voltage
has a high AC ripple complement, then that diode may well go short circuit and there's a reason for the blown
4A fuse in position 1 of the fuse box.
Obviously there's some conjecture here and if the house experts think that I'm talking through my hat (or any
other posterior orifice!) please say so.

As mentioned, there are potentially three problems

1) What (short) is blowing the fuse
2) The dreaded nylon tie wraps problem which can affect any of the items on the handlebar or the instrument panel
3) Lack of output from the alternator, it should be more like 14 to 14.5 vdc at the battery terminals with the engine running at say, 3000 rpm

Best of luck sorting your problem

Thanks guys. I didn't have much time to look at it this evening but Ol' Jeffers post got me to thinking. I had checked the voltage with the blown fuse in place. I put a new fuse in and it read 12.5v off and 13.5v on high idle. That should rule out the alternator/voltage regulator and narrow it down to a short, right?

Thanks Rob, OJ and Boxermania. I'll let you kow how it goes.

The OilHead has a extremely durable car alternator in it and they rarely fail unless some dolt does a reverse polarity jump start. The problem is more likely to be a fried/corroded/broken ground wire or somewhere the charge light circuit is broken. If your red charge light does not illuminate when you turn the key on, your alternator will not have an output charge when the motor runs. That bulb completes the power actuation circuit from the voltage regulator. A broken wire or one wire with only partial unbroken wire strands remaining in the front harness will do the same thing.

With a decent quality DVM, that alternator should show 14.1V at an idle.

.

CycleRob wrote:I think the problems are related. What blew the fuse? It is not supposed to happen unless something is wrong. Very likely it is the same thing that's causing an intermittent connection to the tach. A break in those wires in the wiring harness loop that is physically traumatized when the steering is turned left or right. Damage is a certainty after several years if 2 factory installed zipties are not removed. Check your bike against THIS PIC.

After cutting the nylon ties, do you just leave the wires hanging loosely?
Thanks.

Red1150R wrote:

CycleRob wrote:I think the problems are related. What blew the fuse? It is not supposed to happen unless something is wrong. Very likely it is the same thing that's causing an intermittent connection to the tach. A break in those wires in the wiring harness loop that is physically traumatized when the steering is turned left or right. Damage is a certainty after several years if 2 factory installed zipties are not removed. Check your bike against THIS PIC.

After cutting the nylon ties, do you just leave the wires hanging loosely?
Thanks.

Yes. They really don't hang loose, it just gives a little slack so they don't get pulled/pinched when you turn the bars to the left.

Actually cutting the tes alone doesn't correct the problem, the ties led to the problem by either damaging the wire(s) by the action of the side to side handlebar movements by breaking the wire insuation and or wire strands, leading to intermitent operation or shorts. You need to carefully slice the outer covering of the wire bundle, in the area of the tie, find the broken/severd/shorted wires and fix the problem.