Electrical woes: Open rotor and Relays

[azcycle]

Hello all! I've not been around in quite a while. Having a baby and new jobs tend to do that. The r65 has been putting around until recently, though I've had a growing number of electrical gremlins popping up.

NO CHARGING LIGHT
I've gone blind reading everything on the http://bmwmotorcycletech.info/ website. Great info there, and with it's help I managed to figure out that nearly everything is good, except that either the rotor has "opened" or the brushes are worn (or both).

I plan on purchasing some new brushes and installing, no problem.

Question 1: To test the rotor, I've read I need to do an "ohmmeter test ACROSS the slip rings." I'm not really sure what this means? The rotor is still on the bike, but the stator and stator cover have been removed. I set my multimeter to the Ohm setting and touched the slip rings with the leads. One lead on each slip ring. No matter what Ohm setting I used on the multimeter, I got "OL" displayed, which, according to the user's manual, means "there is no resistance."

Does this mean the rotor is "open" ? Or am I not conducting this test correctly?

NO LOW BEAM AND NO TAIL RUNNING LIGHT
About a year ago, I noticed that the running light on the tail-light stopped working. Wiring and bulb are in good shape, original-style fuses are good (plan on updating those) and the brake light still works.

Then, the LOW beam on the headlight went out. Hi beam and the dashboard indicator light still work, as does the hi-beam flash. Headlight is NOT original and sealed-beam but I checked the wiring and bulb and it looks good.

So I'm thinking the headlight relay is toast. But I simply can't find one to buy anywhere. I've read tons of contradictory information about alternate relays and Motorrad Electric has some but looks like they're only for "/6 bike through 1984."

Question 2: Does this sound like a bad headlight relay?
Question 3: Can someone help point me where I can get a replacement headlight relay? I read this article:
http://www.bmwr65.org/cgi-bin/yabb2/YaBB.pl?num=1277744504/6#6  but it just confused me more.

I think I need:
61 32 1 243 049 -  '78 to '84 "Day-Light/Time" (30, 85, 86, 87, 87b w/ diode 86-87b, park lights lit while starting)

with the possible replacement of:
BMW: 61 32 1 243 049
Type: 12V, 2 x 30A; mini-relay
Notes: '78 to '84 "Day-Light/Time" Headlight Relay (30, 85, 86, 87, 87b w/ diode 86-87b, park lights lit while starting)

Is this correct?

Question 4: When removing the stator, the wound innards are absolutely filthy. Should I clean them and if so, with what? I don't want to damage them.

Hope I've made myself clear... thanks for the help!

[georgesgiralt]

Hello !
A reading of OL on an electronic Ohmmeter means an infinite resistance. Not "no resistance" which would be a reading of zero.
As such, if you put one test lead on each rotor's slip ring, your rotor has it's wire cut somewhere rendering it useless.
Hope this helps.
P.S you should have found something in the range of 2 to 10 Ohm (depending on the rotor and the quality of the meter)

[montmil]

Hey there, Graeme! Congrats on the new baby and a new job. So your're excused for being a wee bit awol.

When testing the rotor, I believe you need to lift the brushes off the slip rings... those two shiny rings on the rotor. If you did not do that, test again.

If the brushes are worn beyond limits, the brush springs may be touching the brush holders and not allowing adequate pressure to keep the brushes in contact with the rotor rings.
   There's an easy "ghetto fix" that you can try. Whittle a couple small wooden rectangles that will fit on top of the brushes. They'll need to "float" within the holders. Put the snail springs back on top of the wooden shims and see if you get better charging results.

I'm betting your "Look good" OEM fuses are a possible problem. I replaced mine with small, mini-blade fuses in waterproof holders. Big help. NAPA has them' Toss the old fuse box and be happy.

With the tank off, locate the headlight relay. Turn on the ignition, put a finger on the relay and toggle the hi-low switch. You should be able to feel the relay "click". If your hearing is good, you might even hear it click. No click? Recheck wiring and try a new relay.

If the headlight relay proves bad, take it and your part number to NAPA and see if they have a cross reference relay.

Radio Shack sells CRC electronic cleaner in a spray can. Won't hurt plastics. Designed for what you want to do in cleaning the stator dirt. Won't hurt it. BTW, the windshield washer pump wouldn't work on my Cabriolet. Jumped the pump motor and it was good. Sprayed a douche bag full of the cleaner into the switch on the steering column... Eurthra!

When you get off Dad Duty, let us know your progress.

[Barry]

The rotor is just a long coil of wire with either end connected to a slip ring. the resistance of the wire should be 3.4 ohms.  The likely failure mode is a break in the wire which will read as open circuit and that would explain your charge light problem. The rotor is a path to earth for the charge light so to confirm the rotor is faulty short across the slip rings and charge light should come on.

Your comments on the headlight relay suggest you might already have Joe Cuda's relay article which has cross references for finding a replacement. If not Snowbum must have referenced it. Send me a PM if you want a copy. I'd post it up here but as it is no longer available to all and sundry (that's us)  I don't think it's fair to put out in the public domain.

[montmil]

I have ABC Kansas AirMarshal Joe Cuda's relay article. I looked up the BMW part # for the headlight relay number quoted by Graeme. It's the same number as in Joe's excellent tech article. I did not find a cross-pollinated replacement unit for the OEM relay. I have previously found replacement relays at NAPA that are not listed in Joe's excellent article, hence my FLAPS suggestion.

I would first confirm the relay is at fault before throwing good money at a part that may be still functional.

[azcycle]

Thanks for the warm welcome back, everyone!

The charge light glows quite nicely when I ground the Df male spade brush connector using a paper clip, per Snowbum's instructions at the top of the page here:

http://bmwmotorcycletech.info/trbleshootALT.htm

What I'll do is replace the stator and cover, shim the brushes so they touch, and turn on the ignition to see if the gen light illuminates. If it does, worn brushes. If it doesn't, bad rotor.

I'll also replace the old fuses. I have everything I need to replace with new style... just haven't done it. Should be a quick job.

Then I'll test the headlight relay and see if I can get a "click."

Do you think the rear taillight running light being out is a fuse issue, or is it somehow tied into the headlight relay?  From what I read on Snowbum's site, I got the impression that the relay DOES keep power to the running light while turning off the headlight so it is tied in somehow... at least that's how I read it.

[montmil]

The small running light inside the headlight body has a power wire and a brown ground wire. Easy to test with a VOM. Same with the tail light. Check for power. No power? Start tracing back.

[azcycle]

The small running light inside the headlight body has a power wire and a brown ground wire. Easy to test with a VOM. Same with the tail light. Check for power. No power? Start tracing back.

Non-stock headlight which doesn't have the running light. I do think the running light wire is still there, just not connected to anything (I think?) Need to get back in and look.  But it also worked that way for years then "all of a sudden" stopped.

But yes, I'll trace power back from the tail light if it doesn't work after replacing fuses, etc.

[montmil]

Just a couple thoughts... Have you jumpered the low-beam terminals to confirm the headlight bulb is good?

The handlebar switch assembly: Have you opened the headlight switch and checked for a bad solder joint, tweaked spring or out-of-place little ball bearing? Big, clear plastic bag with the switch and your hands/tools inside so the small parts don't pop out and pass into some other dimension.

[azcycle]

Just a couple thoughts... Have you jumpered the low-beam terminals to confirm the headlight bulb is good?

The handlebar switch assembly: Have you opened the headlight switch and checked for a bad solder joint, tweaked spring or out-of-place little ball bearing? Big, clear plastic bag with the switch and your hands/tools inside so the small parts don't pop out and pass into some other dimension.

1) No, I'm not sure how to jumper the terminals. I'm very much an electrical "newbie."

2) No, but it's also on my list of things to do so I can check it off the list of potential solutions/problems. I did crack the two halves apart and spray a ton of electrical cleaner in there, but that's all I've done.)

[azcycle]

Small update: I felt/listened to the headlight relay when I switched on the ignition and felt/heard a very distinct "click" so seems to me the relay is still good.

I'll test the voltage downstream from the switch on the low beam wire and see what I get.

What is the best way to test the headlight without burning something up (including myself) ?

[Barry]

You could use the ohm meter to check the headlight bulb filaments are OK.  The resistance values will be so low that they will read as a short circuit i.e. the same as shorting the two meter probes together.

[azcycle]

Progress!

I removed the left switch and carefully "disassembled" it (meaning: pried it open with a screwdriver). The plastic was old and brittle and there was some collateral damage but nothing vital, thankfully. Things in there were gummy, dirty and a tiny bit corroded. But everything worked well, and I got solid "clicks" for low and high beam.  Couldn't find anything obviously wrong so I cleaned everything up and reassembled/installed.

I decided to test the switch at the back of the headlight bulb, and low and behold... I had power on the low-beam at the back of the headlight.  So the sealed-beam headlight is bad.

I then moved to the tail-light, which hasn't been working for a while, despite a new bulb. I tested power at the socket and I had power! Scrounged around the garage until I found a good bulb, plugged it in, and ... had a working tail-light!

Shouldn't assume that a brand new bulb is good, I guess.

Inspected the alternator/rotor brushes and while they are worn, they had plenty of life left and were pressed against the slip rings snugly with lots of spring movement still left.

So:  I ordered a new rotor and it should be here tomorrow.

I've decided to go BACK to a BMW-style headlight and dump the small, dim, generic one my father-in-law had on there. Thankfully, in the parts bin, I still have the r65 bucket, lens and light (just missing the trim ring, which I know is worth it's weight in gold).  I ALSO have a light/lens and trim ring to an older, larger style BMW light. All I have to do is buy a bucket... just need to find one the right size.

[montmil]

    Lesson learned, eh, Graeme?

Here's another helpful "should be obvious, but..." tip for you:

Shut off engine before replacing fan belt. This statement is printed on most every fan belt package sold today... at least in the USofA.

[azcycle]

Well, a small and slightly frustrating update:

Got the new rotor delivered and I carefully installed it, along with brand new brushes. I followed all directions and as far as I know, didn't break/nick any wires, etc. Turned on the key and was very happy to see a brightly lit charging light!

Then I went to hit the start button and was met with complete silence. Not a click, not a puff.... nothing. It started fine (see * below) before I replaced the rotor... it just wouldn't charge. I triple checked myself when installing so stator insulators are correct, wires are connected correctly, and the new rotor shows resistance between the slip rings. I even "magnetized" the rotor according to Snowbum's recommendation.

* Now, the start button WAS acting funny recently and sometimes would require a bit of "wiggling" while pushing to get it to engage. So I'm hoping/thinking that maybe it finally died. Just bad timing. I'm going to test the starter relay and starter button and hope they are the cause of this. I still have the old-style fuses and will replace those, too. Engine is in neutral (though I know the neutral sending unit is bad).

But does anyone think that replacing the rotor would cause this "no start" issue?