Go Back   ADVrider > Bikes > Old's Cool > Airheads
User Name
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Thread Tools Search this Thread Display Modes
Old 12-13-2004, 03:44 PM   #1
Malindi OP
Zen Adventurer
Malindi's Avatar
Joined: Jul 2001
Location: Vancouver, BC
Oddometer: 5,421
Motorrad Omega 400 problem

I mod a list for G/S bikes (monolevergs on Yahoo) and this question came in. I don't have an Omega, but maybe someone can e-mail Svante and/or post a diagnosis here?


Got the Omega 400W alternator with replacement diode board installed on
my '96 GS Basic, and has been very pleased with the performance for some
10K miles. But this autumn the charge indicator bulb began to
intermittently refuse to turn off, but stayed glowing partially even at
full revs. And finally never turned off completely. I thought it had to
do with my clock sometimes refusing to work, but after fixing the clock
(found a loose, tiny bulb inside the housing, intermittently
short-curcuiting the connection) the indicator bulb still stays on
partially glowing. Voltage is correct (have also checked with another
regulator installed). Regarding the diode plate I found the checking
procedure described in "Classic boxer charging" a little confusing.
Measure gives correct readings between AC input terminals and the D+
terminal, and also from all the G connections but there is no B+
assigned. I choosed the connector for the red wire to the starter engine
(B+ on the Thunderchild board) and then I get bad results, with big
resistance results in both directions for all the AC input terminals.
U = 3 vs 1,1 MOhms
V = 5 vs 1 MOhms
Y = 7,5 vs 0,8 MOhms
W = 15 vs 0,7 MOhms
This seems a little odd, are really all four diodes fried? Giving no
more noticeable sign then a glowing charging lamp?Or is there something
wrong with checking the board this way? Has anyone information about the
correct checking procedure and results for the Omega diode board? Of
course I will also appreciate information about any specific problems
noticed with the Omega charging set up so far.

Best regards

Svante Brandén, Stockholm, Sweden
R75/5 '73, LWB, black, "Devil"
K100RS '87, Motorsport, white, "Hero"
R100GS '96, Kalahari (mod Basic), white/blue, "Fraka"
Back in YVR after riding around the world for 2 years.
Malindi is offline   Reply With Quote
Old 12-13-2004, 04:20 PM   #2
Frank Warner
Frank Warner's Avatar
Joined: Mar 2002
Location: Sydney, Australia
Oddometer: 6,593
Diode checking with a meter is dependant on the meter used. Some have a specific range for diodes, others you have to know what they do. Best to check a new diode - that should tell you what to expect when checking other diodes.

Larger diodes can have a some what different effect on the meter indications. If all the diodes on the board read the same I'd say they are ok.

The glowing light may simply be that the alternator side is at a higher voltage than the keyed ignition side - that is a voltage drop from the battery through probably a fuse, the ignition key, kill switch to the globe. You would need to do some voltage readings around the circuit to find the problem, not resistance readings. Measure the voltage on both sides of the globe - bet the alternator side is higher than the ignition switch side.
Regards Frank Warner
motorcycles BMW R80 G/S 1981, BMW K11LT 1993, BMW K75 G/S
Frank Warner is offline   Reply With Quote


Thread Tools Search this Thread
Search this Thread:

Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump

Times are GMT -7.   It's 05:16 AM.

Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2015