Circuit protection

[hawghd1]

I am currently wiring my 1950 pan and couldn't help but notice that there is no circuit protection coming off the battery hot wire. I want to install an in line self resetting circuit breaker. Can anyone tell me what size breaker would work best? Not sure if I should use a 20 amp, 25 amp or 30 amp. I have a stock 32 E generator 6 volt system.
Thanks

[ricmoran]

15 amp. Been running an in line mini fuse 15A with my 1939 Knuckle 6 volt system for some years now with no issues.

[Panacea]

I had one on my 51, installed on the bottom of the dash plate. I can't remember the amp rating but I would think 15 would work unless you have a bunch of extra lights on her...

[awander]

Of course, if you're gonna' go "by the book", then any time the battery is disconnected and reconnected(as would happen if the breaker opens up and then resets), you should polarize the generator.

And you won't really know for sure if the breaker opened and then reset while the bike was parked, so you should polarize your generator every time before you start the bike.

Fuse might be easier, as you will know if it opens up.

I know some will say that polarizing the generator is not necessary, but I think they would not have bothered putting it in the manual if it was not a good idea.

[frichie68]

Wouldn't the gen-light come on if it's not charging?
Or in the case of an ammeter, show discharge?

[awander]

Wouldn't the gen-light come on if it's not charging?
Or in the case of an ammeter, show discharge?

Yeah, I guess it would.

What would be your first thought then, "Gee, my circuit breaker must have disconnected and reconnected the battery, and the generator lost it's residual magnetism. I'd better shut down and polarize the generator!", or "What the hell is wrong with the charging system? Maybe the battery is bad-or there's a loose ground-or the relay is sticking-or maybe the generator needs brushes...."

[hawghd1]

I think I'll try the in line fuse. Thanks

[t-jacobs]

Fuses are small so it is easy to carry spares on the bike just in case. I have some wrapped in a piece of cloth in my tool box.

[MMasa]

You should use one of the replica H2 battery's from Erdos. It has a fuse hidden inside the case where you can't see it and it looks like a real HD battery on the outside. It also will never drip acid on your tranny.
Mark

[TimR]

Awander, You have my curiosity as to what book explains the procedure to "polarize the generator" for a 32E generator or for that matter any third brush type generator. Thanks Tim

[Rooster]

Awander, You have my curiosity as to what book explains the procedure to "polarize the generator" for a 32E generator or for that matter any third brush type generator. Thanks Tim

Harley-Davidson Service Manual.

[billpedalino]

After all these years, I've only polarized 2-brush generators. Never had a problem with 3-Brush units not charging.

[awander]

Hey TimR, that is a good question! I was going to say that it is in both the 1940-47 and the 1948-1957 Service Manuals, but I decided I should look for it first.

It seems you may be on to something, as the only mention I can find in those 2 manuals is under the "Current and Voltage regulator" section, which, of course, applies only to 2-brush generators.

Thanks for pointing that out-or at least asking the question.

[ricmoran]

Been removing the fuse after every ride and then inserting the fuse before riding without any charging issues.

I do use a battery charger however that has the float mechanism as I want to get all the time from the battery that I can. Don't have an acid issue as I've been using CP-90 to protect everything so acid vapors do not cause issues with corrosion.

[billpedalino]

Ricmoran - I use the same in-line fuse procedure with my '47, as well as use acid-neutralizing pads on top and bottom of the battery. Richie Brown (the 32E Generator guy) introduced the pads to me and you can buy them from JC Whitney. However I'm not familiar with 'CP-90'. Once again I display my ignorance - What is that?