Generator/Idiot light/relay wiring question

Electrical issues
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LittleAl
Posts: 263
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Bikes: 1954 FL Panhead
1976 Sporty
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Generator/Idiot light/relay wiring question

#1

Post by LittleAl » Sat May 16, 2009 7:41 pm

On my '54 FL I'm running 12 volts, Bosh 5 post 12 volt relay and CE generator.

This is how I have it wired so far:

Generator F goes to relay DF
Generator A goes to relay D+
Relay is grounded

the battery "hot" lead that goes to relay B+ seems like it is supposed to go to the ignition switch terminal 1 (hot all the time) is this correct?

on the idiot light:
the socket is totally insulated from the dash base so I'm thinking it doesn't matter which wire goes to terminal 61 on the relay, but the other lead gets what? ground or switched positive? If positive I'm thinking it has to be switched, only juiced when ignition switch is on

so can anyone tell me what I have right, wrong?



FlatHeadSix
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Re: Generator/Idiot light/relay wiring question

#2

Post by FlatHeadSix » Sat May 16, 2009 8:16 pm

good guesses all around Al!

One side of the idiot light gets switched +, doesn't matter which one, the other side goes to the terminal on the regulator.

I'm not exactly sure about the internals of the Bosch regulator but I think the terminal for the idiot light will supply generator output voltage when it starts to produce electricity, when it gets up to speed both sides of the idiot light will have the same potential and it will go out. Systems wired like that can have an idiot light which will glow very dim when the generator output is almost but not quite at full voltage which will indicate a partial or low charge rate.

The old 3-brush systems used a relay which was either on or off, when the generator was not producing juice the relay contact for the idiot light was closed and went straight to chassis ground.

mike

LittleAl
Posts: 263
Joined: Fri Jan 02, 2009 8:52 pm
Bikes: 1954 FL Panhead
1976 Sporty
1983 FXRT Shovelhead
2000 FLHT TC
2008 Anniversary Ultra
Location: New York City

Re: Generator/Idiot light/relay wiring question

#3

Post by LittleAl » Sat May 16, 2009 9:23 pm

Thanks Mike!

What about the positive to the regulator? should it have juice all the time or only when the ignition is on?

FlatHeadSix
Moderator
Posts: 2685
Joined: Sun Jun 06, 2004 5:14 pm
Bikes: '31 VL, '34 VD, '45 WLA, '47 WL, '49 FL, '51 WL, '58 ST (Hummer), '71 GE (Servi)
Location: Lonoke, Arkansas

Re: Generator/Idiot light/relay wiring question

#4

Post by FlatHeadSix » Sat May 16, 2009 11:49 pm

Al
One of the components of the regulator is a relay (cut-out) just like the old 3-brush gennies had, so one of the terminals on the regulator will always be connected straight to the battery + side. Hopefully the relay won't stick and keep the battery connected when the engine isn't running, that's what usually happened to the old relays when they went bad, it would drain the battery overnight.

Isn't today your deadline?, is it running yet? We're all plugging for you here!

mike

p.s. your wife called, she wants to know when you will get the bike out of her kitchen! lol :wink:

LittleAl
Posts: 263
Joined: Fri Jan 02, 2009 8:52 pm
Bikes: 1954 FL Panhead
1976 Sporty
1983 FXRT Shovelhead
2000 FLHT TC
2008 Anniversary Ultra
Location: New York City

Re: Generator/Idiot light/relay wiring question

#5

Post by LittleAl » Sun May 17, 2009 12:56 am

thanks Mike. I'm done with that final bit of wiring now.

as far as your other comments:

well technically, yesterday was my deadline. I'm waiting on the tins. I just got home from the painter. the tanks are done, fenders will be done tonight. If you remember I'm doing the tanks Daytona Ivory and the fenders Glacier Blue. He's shooting the blue tonight. after rub out tomorrow morning he'll shoot the clear on both, final rub out & polish. Picking everything up about 3.

I only have the usual finish stuff to do along with putting on the tins, maybe about 6-8 hours work left. So, I'll be a few days late! The OL is a non-live in girlfriend (except for weekends) so I'm cool there, lol

She'll (the bike, not the OL) will be out of the kitchen, complete, one evening this week and get her first attempt at starting. Next weekend is Rolling Thunder in DC which I've only missed 4 times in the last 19 years so I'd like to get everything done before Friday.

thanks for reminding me i failed at meeting my deadline, lol my NEW deadline is to get my virgin ride on Monday 5/25, Memorial Day.

I'm sure I'll be posting a few more last minute questions this week...

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