Board index Flathead Power-Technical Questions, Answers, and Suggestions 45 Flatties genarator charging problem

genarator charging problem

Moderators: Curt!, Pa

Post Tue Mar 18, 2014 5:29 am

Posts: 16
I have a resently restord Orginal WLA, restord the generator buy book, generator is 32e, 3 brush, 6volt, reley solid state 6v.

Ive notis late last sommer(end of seoson in Sweden), that front head light vas broken.
Change to new 35/35 w that one broke(burnd) at once..the long beem light was still working....
Change to 25/25 w bouth normal and long beem broke when testing....

Checkt voltage=OK, and change third bush to direction ACW, it almost at end now
checkt current bethen gound an batteri minus = To high +10 AMP when reving engine, (to high!)...but only when switch is in head light position,-in parking light position now problem whit current.

What can it be??????
Has the generator broke?
Wireing, batteri gone bad?

Post Wed Mar 19, 2014 8:43 pm

Posts: 1642
Location: Interlaken, NY USA

Very Interesting.... couple of questions.
First, with the switch in headlight position, the current at the battery minus terminal is 10+ amps, right?
Is this the reading you get when the headlight has blown?, Or, do you get this reading with the headlight on and shining?
Reason I ask, if the reading is 10a with a blown headlight, that may be o.k. You've just switched on extra generator output, but it has no place to go except the battery if the headlight is blown.
Next, have you blown a taillight while doing these tests?
IF not, then here's one way to look at the problem.
You say the voltage is o.k, and because the taillight hasn't blown, that seems to reinforce the theory that the voltage IS o.k.
Which leads to one conclusion, something's wrong with the headlight and or bulbs.
The usual blowing headlight bulb problem is a bad ground between the headlight and the battery. But, they usually don't go "POP" like flashbulbs if that's the case. It takes awhile.
I doubt that it's bad bulbs, 'cause you've tried two of different types. But it could be.
Try this if you can;
Get a different voltmeter, to verify your voltage readings. Either a high quality digital or a good quality analog.
IF the voltage is really o.k, then make up a test jig with a headlight bulb so that you can connect it directly at the battery with alligator clips, or better yet, test leads screwed to the terminals. See if the lamp will survive. If it does, great, we've verified the generator and battery.
If your test rig has alligator clip leads, move to the ignition switch, and hook to the headlight terminal and a good ground on the frame near the switch.
If it still works o.k, we've pretty much narrowed it down to some sort of wiring problem to the headlight, so go after it.
This is all based on the premise that the voltage IS GOOD, and the taillight has survived to date.
Keep up posted on what you find.

Post Thu Mar 20, 2014 9:33 am
Pa Site Admin

Posts: 5551
Location: Ohio USA

The only time I've popped a bulb as your bulb popped, was when I mistakenly installed a 6 volt bulb into a 12 volt socket.

Post Thu Mar 20, 2014 9:51 am

Posts: 301
Location: Ohio
I was having a problem with mine blowing bulbs until I chased the problem down to a bad ground in the head lamp bucket. After running a dedicated ground wire to the headlamp bucket the problem hasn’t come back. The way these things are originally grounded was a piss poor idea.

Post Thu Mar 20, 2014 6:23 pm

Posts: 536
Location: Wa, USA
I had this same problem on my WLA and have seen it on other bikes also. If there is not a ground wire to the frame from the headlight or front forks, the ground path is through the neck bearings and that causes headlight bulbs to fail. Grounding directly to the frame usually cures this.

Post Fri Mar 21, 2014 7:50 am

Posts: 16
All tailaights bulbs are still ok and i know i had problems thit the headligt grounding when i put the bike together.. :roll:
I will be making some tests this wekend..will feedback later.

Tanks for god info! :)

Post Mon Mar 24, 2014 12:55 am

Posts: 16
Yes it was the ground-problem!
Thanks for feedback :D

Return to 45 Flatties