Stuck in Toronto

[Bob_Roller]

Charging system output should be checked with engine rpm's around the 4000 area, this is where the charging system really starts working .

A test for the regulator is pretty quick,  remove the connector from the regulator, and place a wire 'jumper' between the terminals for the black and blue wires, this completely removes the regulator from the circuit, and puts full battery voltage to the rotor, the alternator will now produce as much electrical power that it can .

[invincibleone]

Yes, I plan to test it tonight. I'll get back with results. I thought that if all is well system should put out 14V (+/- 0.25V) at 2000 rpm when blue is jumped to black on regulator harness.

[Bob_Roller]

It all depends on the state of charge of the battery as well, if the battery is not in a full state of charge, the excitation voltage to the rotor will be lower, and a lower output of the alternator will result .

The speed of the rotor is another factor, seeing as how the rotor spins at crankshaft speed, most alternators are 'geared' to rotate around 3 times engine speed, so even at idle, they are spinning around the 3-4000 rpm area.

The rotors on our bikes don't get to that speed until you get up to highway speeds .

If you routinely ride in 'city' traffic you will have a chronically low state of charge on your battery, due to the low output of power from the Bosch charging system on our bikes .

When I lived in Chicago, I had a 5 mile ride to work, with 13 stop lights, if I didn't put a battery charger on the bike overnight at least once every 5 days, the battery would be 'dead' on the sixth or seventh day .

[invincibleone]

It all depends on the state of charge of the battery as well, if the battery is not in a full state of charge, the excitation voltage to the rotor will be lower, and a lower output of the alternator will result .

The speed of the rotor is another factor, seeing as how the rotor spins at crankshaft speed, most alternators are 'geared' to rotate around 3 times engine speed, so even at idle, they are spinning around the 3-4000 rpm area.

The rotors on our bikes don't get to that speed until you get up to highway speeds .

If you routinely ride in 'city' traffic you will have a chronically low state of charge on your battery, due to the low output of power from the Bosch charging system on our bikes .

When I lived in Chicago, I had a 5 mile ride to work, with 13 stop lights, if I didn't put a battery charger on the bike overnight at least once every 5 days, the battery would be 'dead' on the sixth or seventh day .

Thanks for the further input. I was planning on performing the test with a fully charged battery.
While I don't think you were suggesting this, when I left Toronto the battery was fully charged at around 13.3v and every time I stopped for gas (twice) on the 527 mile journey home as well as when I finally got home, the battery was right around 12.3v. While I may have hit a touch of traffic on my way home, the vast majority of those miles were at or well above 3500 rpm, especially the last 100 miles or so; so the battery shouldn't have been below 13.0V. (?)

[Bob_Roller]

The battery voltage should have been high after running at that speed for that time .

Have you checked the voltage at the battery, with the engine at 4000 rpm, it should be right around 14 volts .

That's all I would be really concerned about .

[montmil]

Old wires, Fissel, old wires and connections.

Start with new NAPA-made battery ground and positive wires with copper terminals and heavier gauge wire.

Then, "in your spare time," begin replacing the OEM wires and terminals as far as you can go within the charging system. Failing that, replace the spade terminals. Most are likely corroded and providing much resistance throughout the system.

You'll be surprised at what a difference this will make in the BMW's charging performance.

Photo of my latest R65 battery ground strap...

Monte

Doubtful. This bike has just over 16,000 miles on it and 3,500 are from me in the last few months. The bike has never spent a night outside and I haven't seen signs of electrical corrosion anywhere.

Rather than just replacing wires thought to possibly be bad I could simply ohm each of them out to see if any have excessive resistance. But if there was enough resistance to drop a volt (or more) we would be producing a fair amount of heat, and that doesn't seem to be the case.

I have a gut feeling it is the voltage regulator.

Could be the regulator... along with several other small bits that, when taken alone, do little impact the electrical circuitry but, when multiplied, do create voltage and resistance issues.

It has been my experience that mileage, or Hobbs hours, on any vehicle has little to do with the galvanic action taking place between dissimilar metals. BMW wiring utilizes the smallest (and cheapest) wiring as a manufacturing price point along with weak spade connectors that lose grip and increase resistance after the very first factory assembly. YM -and voltage-MV.

Monte

[invincibleone]

Alright, regulator test finds voltage at 3500 rpm with regulator hooked up to be around 12.3 volts. With regulators blue wires jumped to black wire at same 3500 rpm voltage climbs to a shade over 14 volts.
Looks like I'll be calling Bob's BMW for a voltage regulator tomorrow.
Thanks for the help. I'll post a confirmation of repair with new regulator.
-Fissel the Missile

[nhmaf]

I tend to carry a spare regulator inthe compartment under my seat.  I know some folks who won't leave home without a spare diode board, but I haven't gone that "boy-scout" yet..

[invincibleone]

I tend to carry a spare regulator inthe compartment under my seat.  I know some folks who won't leave home without a spare diode board, but I haven't gone that "boy-scout" yet..

Do they really fail with that kind of regularity? The more I learn about the BMW charging system the more it scares me.

[nhmaf]

No they don't fail often, but when one has a ~30  year old piece of machinery, with parts that aren't always found at every NAPA/Pep Boys store, one tends to carry a few items that may get one out of a jam someplace (or help a fellow airhead out of a jam).    You do carry a spare inner tube, don't you ?

Since we have alot of new and returning airhead riders these days:
I'd also recommend to anyone in US or Canada to join the BMWMOA.   Their "Anonymous" book (listing of BMW owner locations & phone #s who are willing to help out a stranded/distressed rider in need) is good backup/insurance.    I am in there, and while I personally haven't had to get help from another member, I have friends who were saved by some "angel"  who appeared with a spare part and cup of coffee, or a trailer, or provided a garage and full set of tools to work on a bike.  One friend had the rear shock on his K75RT blow apart on a Saturday night while he was on a long tour 1000 miles from home - he was basically done at that point, but as it happened, a BMWMOA member drove 20 miles to meet him and gave him an almost new shock off his own K bike.   You may meet the friendliest people on a Honda, but you meet the most helpful people on a BMW.

[Bob_Roller]

The charging system isn't really overly problematic, I personally have 82,000 miles on the original components .

Though I know my diode board will most likely be the first part to give up it's job, due to running two 55 watt drivings lights for the last 6 years .

But like Nhmaf has mentioned, the bikes are in the 25-30 year old range, even if they have low mileage, and failures are to be expected, can you imagine what kind of problems you would have with a 4 wheeler of similar age .

[Yikes]

Hey Missle, unless you're really intent on keeping everything OEM, you should check Motobins for that voltage regulator.  It's way less than the one from BMW.  You could buy two, mount one, and have a spare for less $.

[invincibleone]

No they don't fail often, but when one has a ~30  year old piece of machinery, with parts that aren't always found at every NAPA/Pep Boys store, one tends to carry a few items that may get one out of a jam someplace (or help a fellow airhead out of a jam).    You do carry a spare inner tube, don't you ?

Since we have alot of new and returning airhead riders these days:
I'd also recommend to anyone in US or Canada to join the BMWMOA.   Their "Anonymous" book (listing of BMW owner locations & phone #s who are willing to help out a stranded/distressed rider in need) is good backup/insurance........................................................

Well said.
And no, I don't carry a spare tube, but for the Toronto Trip I did carry a Rema Tip-Top M/C patch kit; which takes up far less baggage space than a tube.
I also agree with the bit about the BMW-MOA. I was actually a member back in 2002 when I had my last BMW, an R90. I had every intention a joining prior to this journey but it just slipped my mind until I was packing the night before. I actually had my old 2002 Anonymous book with me, but I didn't attempt to call anyone as I had the issue more or less under control (ie the bike was safe in a friends shed, I had a place to stay & I was able to order the parts from the local dealer). Had the bike broken down en route home (in rural up-state NY) I certainly would have been mad at work dialing those 7 year old numbers.

[invincibleone]

Hey Missle, unless you're really intent on keeping everything OEM, you should check Motobins for that voltage regulator.  It's way less than the one from BMW.  You could buy two, mount one, and have a spare for less $.

Are you talking about this???
http://www.motobins.co.uk/displayfinal.php?q=73115&go=GO
That is basically the exact same price as the oem part. Plus I already ordered it from Bobs BMW (for $85.54 shipped as I am too busy this week to make the 60 mile drive down)
And whenever possible I do prefer OEM.

[montmil]

...I'd also recommend to anyone in US or Canada to join the BMWMOA...

Ask ol' Bengt just how helpful his BMWMOA road service policy was when he was broken down and got connected with an out-source call center somewhere in Bumfukistan. I prefer the Airheads BMW Club...

Monte, ABC 12411