HarleyTechTalk

Hey guys I need some help. I have a 2000 FLHTCUI. I want to replace the 50 Circuit Breaker with a 50 Amp Maxi Fuse. I know some of you have done this to your bikes of that era. I would like to see some pictures of how it is done. I had the Circuit Breaker moved to the right side in order to get away from the heat of the header. I still had a shutdown back in the summer right after sitting at a long traffic light........I'm done with the piece of crap Circuit Breaker!!!! I've had some close calls due to this part. Please, HELP!

I didn't read the whole thread but it looks like it may help:

http://harleytechtalk.com/htt/index.php?topic=23854.0

I didn't read the whole thread either, but early on there is expressed concern about the fuse opening and leaving the voltage regulator feeding the bike's electrics with no battery then attached to the circuit.  It looks like they were talking about going with a second fuse to protect the electrics from potential over-voltage in that case.  I don't think it would do that unless the voltage got so high that the fuse couldn't handle it.  But fuses are primarily current limiting, not voltage limiting.  In fact, in a DC circuit where we're not seeing reactive loads - just resistive - any load would present fewer amps as the voltage goes up so the fuse would be even less effective.

I'd merely (and exactly) replace the breaker with a fuse and call it good.

When I do them I get the HD Maxi Fuse holder and pins. Then make up a new wire from the starter up to Maxi Fuse. Then make up a short lead from the other side of the fuse to a ring terminal. Then just use one post on the old breaker as a tie point. Set the wire length so you can velcro the maxi fuse case on the surface of the fuse block cover. There is no need for two fuses.

If you didn't read the whole thread at least read what caused the breaker to trip, the crimping on the wires caused the breaker to overheat and trip.
Very interesting.

Quote from: Coyote on April 22, 2015, 05:40:00 PM
When I do them I get the HD Maxi Fuse holder and pins. Then make up a new wire from the starter up to Maxi Fuse. Then make up a short lead from the other side of the fuse to a ring terminal. Then just use one post on the old breaker as a tie point. Set the wire length so you can velcro the maxi fuse case on the surface of the fuse block cover. There is no need for two fuses.

Coyote, what size wire/holder do you use?

Quote from: harley_cruiser on April 22, 2015, 07:07:12 PM

Quote from: Coyote on April 22, 2015, 05:40:00 PM
When I do them I get the HD Maxi Fuse holder and pins. Then make up a new wire from the starter up to Maxi Fuse. Then make up a short lead from the other side of the fuse to a ring terminal. Then just use one post on the old breaker as a tie point. Set the wire length so you can velcro the maxi fuse case on the surface of the fuse block cover. There is no need for two fuses.

Coyote, what size wire/holder do you use?

Same as stock. 10 gauge primary wire and the Maxi Fuse holder that HD sells. You buy it and the pins. I just hand crimp and solder the two pins.

I cut and solder the connections.
Wait, wrong thread (he says, being a smartass).

Quote from: Hossamania on April 23, 2015, 09:12:45 AM
I cut and solder the connections.
Wait, wrong thread (he says, being a smartass).

Quote from: Coyote on April 22, 2015, 08:27:32 PM

Quote from: harley_cruiser on April 22, 2015, 07:07:12 PM

Quote from: Coyote on April 22, 2015, 05:40:00 PM
When I do them I get the HD Maxi Fuse holder and pins. Then make up a new wire from the starter up to Maxi Fuse. Then make up a short lead from the other side of the fuse to a ring terminal. Then just use one post on the old breaker as a tie point. Set the wire length so you can velcro the maxi fuse case on the surface of the fuse block cover. There is no need for two fuses.

Coyote, what size wire/holder do you use?

Thanks, quick question, how about just moving the alternator/regulator wire to the other side of the stock breaker and leaving the breaker?
Same as stock. 10 gauge primary wire and the Maxi Fuse holder that HD sells. You buy it and the pins. I just hand crimp and solder the two pins.

I'm not completely sure what you are getting at but here is how I do it.

I remove the wire from the breaker to the starter and toss it. The reason I replace this wire is it needs to be longer to locate the Maxi Fuse under the side panel.  So I cut a wire the right length to go from the starter to the MaxiFuse. I also make a new wire to go from the other side of the fuse back to the old breaker. I use the stud on the breaker to connect the Maxi Fuse to the existing wire from the regulator.

So one side of the breaker is being used as a tie point, the other side is not connected to anything. HTH

[attach=0]

OK I am confused:-) I thought the idea was to move the alternator input to the battery side of the breaker/fuse so that if the breaker/fuse tripped the spike would not take out all the electrical componets

Like this image from the other thread, only with one fuse

Quote from: harley_cruiser on April 23, 2015, 05:54:24 PM
OK I am confused:-) I thought the idea was to move the alternator input to the battery side of the breaker/fuse so that if the breaker/fuse tripped the spike would not take out all the electrical componets

The circuit breaker or the fuse, if so equipped, does not protect against voltage spikes, unless as a side-effect when the voltage goes so high that there's insufficient insulation present in the fuse/holder or breaker...  They protect against too much load being placed on the source of power (or the wiring from it).

Quote from: glens on April 23, 2015, 06:24:29 PM

Quote from: harley_cruiser on April 23, 2015, 05:54:24 PM
OK I am confused:-) I thought the idea was to move the alternator input to the battery side of the breaker/fuse so that if the breaker/fuse tripped the spike would not take out all the electrical componets

The circuit breaker or the fuse, if so equipped, does not protect against voltage spikes, unless as a side-effect when the voltage goes so high that there's insufficient insulation present in the fuse/holder or breaker...  They protect against too much load being placed on the source of power (or the wiring from it).

Yes, understand, I was under the impression the spike was caused by the breaker tripping and because the alternator was on the load side of the breaker it did all the damage to the electrical components.

Quote from: Coyote on April 22, 2015, 05:40:00 PM
When I do them I get the HD Maxi Fuse holder and pins. Then make up a new wire from the starter up to Maxi Fuse. Then make up a short lead from the other side of the fuse to a ring terminal. Then just use one post on the old breaker as a tie point. Set the wire length so you can velcro the maxi fuse case on the surface of the fuse block cover. There is no need for two fuses.

Quote from: harley_cruiser on April 23, 2015, 06:41:42 PM

Quote from: glens on April 23, 2015, 06:24:29 PM

Quote from: harley_cruiser on April 23, 2015, 05:54:24 PM
OK I am confused:-) I thought the idea was to move the alternator input to the battery side of the breaker/fuse so that if the breaker/fuse tripped the spike would not take out all the electrical componets

The circuit breaker or the fuse, if so equipped, does not protect against voltage spikes, unless as a side-effect when the voltage goes so high that there's insufficient insulation present in the fuse/holder or breaker...  They protect against too much load being placed on the source of power (or the wiring from it).

Yes, understand, I was under the impression the spike was caused by the breaker tripping and because the alternator was on the load side of the breaker it did all the damage to the electrical components.

Alternator on the load side?

How much do you envision the voltage spiking?  The insulation in the system is good for upwards of a kilovolt, I'm sure.  I don't see the alternator reaching anywhere near that, not even peak; likely never see triple digits as a guess.

If there were a damaging voltage spike as you suggest, a 40A fuse ain't gonna prevent it passing through.

How did this spike get past the regulator, anyway?  Did it fail?

Quote from: glens on April 24, 2015, 06:17:18 AM

Quote from: harley_cruiser on April 23, 2015, 06:41:42 PM

Quote from: glens on April 23, 2015, 06:24:29 PM

Quote from: harley_cruiser on April 23, 2015, 05:54:24 PM
OK I am confused:-) I thought the idea was to move the alternator input to the battery side of the breaker/fuse so that if the breaker/fuse tripped the spike would not take out all the electrical componets

The circuit breaker or the fuse, if so equipped, does not protect against voltage spikes, unless as a side-effect when the voltage goes so high that there's insufficient insulation present in the fuse/holder or breaker...  They protect against too much load being placed on the source of power (or the wiring from it).

Yes, understand, I was under the impression the spike was caused by the breaker tripping and because the alternator was on the load side of the breaker it did all the damage to the electrical components.

Alternator on the load side?

How much do you envision the voltage spiking?  The insulation in the system is good for upwards of a kilovolt, I'm sure.  I don't see the alternator reaching anywhere near that, not even peak; likely never see triple digits as a guess.

If there were a damaging voltage spike as you suggest, a 40A fuse ain't gonna prevent it passing through.

How did this spike get past the regulator, anyway?  Did it fail?

Did you read the thread that was mentioned above about this issue?
Read at least the first post, and what fsg has to say about where the regulated is attached to the breaker.

If you understand ohms law, on you are on the right track. Volts is pressure, amps is flow. Fuse or breaker won't be an issue.
Loss of voltage maybe an issue - bad connections = resistance.
PM me if you need some guidance.

Not sure if this applies to what is being talked about,
Are we talking about the breaker that's under the seat by the battery,
mine is a 03 Bagger. the breaker looks a little rusted and I'm going to
replace it. I'm guessing stock was a 40amp breaker and updated one
is a 50amp? But it should be replaced with a Maxi 50amp fuse?