Position of fuse(s) holder in the wiring loom

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JEAN-NOEL
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Position of fuse(s) holder in the wiring loom

Post by JEAN-NOEL »

Hello gents,
I am a poor mechanist, but a worse electrician !
I am fitting a new genuine Lucas 3 phases alternator stator, with a Reg/rectifier to suit. The instructions sheet says : "a fuse must be fitted in the live battery feed. Is this fuse sufficient to protect all the wiring loom, or another is needed ? At what place ?
Cheers. J.N.
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Harry44
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Re: Position of fuse(s) holder in the wiring loom

Post by Harry44 »

Old British bikes survived on one fuse for many years. If you have indicators you might put a separate fuse for them, so that a short circuit there would not stop the headlamp and tail lamp from working. The fuse should be as close as possible to the battery to keep the unprotected wiring as short as possible.
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kernow kid
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Re: Position of fuse(s) holder in the wiring loom

Post by kernow kid »

Hi, as already mentioned, close to the battery positive terminal. I use the splash proof blade fuse holders as they are robust and blade fuses are readily available. Your three phase system maybe rated at over 200watts, so you can run higher wattage headlight bulbs...you may want to fit a 15amp fuse if you do. I'd also consider fusing indicators and the horn separately, maybe with mini blade holders. 5 amp would be fine.
Regards kk
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56G80S
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Re: Position of fuse(s) holder in the wiring loom

Post by 56G80S »

I could be well wide of the mark here. but I have fitted a fuse, as you say, as close to the battery as possible.

I sometimes just pop that out when doing anything electrical rather than completely disconnecting the battery; it's a lot easier!

I will also take your excellent advice regarding the indicators I fitted thanks.

Johnny B
JEAN-NOEL
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Re: Position of fuse(s) holder in the wiring loom

Post by JEAN-NOEL »

Hello,
thank you for your help. Very clear and interesting.
Kind regards.
J.N.
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spookefoote1956
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Re: Position of fuse(s) holder in the wiring loom

Post by spookefoote1956 »

Mine is right next to the battery
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Matt Durkin
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Re: Position of fuse(s) holder in the wiring loom

Post by Matt Durkin »

I think I also read somewhere, contrary to usual vehicle electrics, that it's wise to put an inline fuse in the earth/negative circuit to safeguard from any mishaps when working on the bike (bridged spanners/screwdrivers etc across components) or have I just imagined that??
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clive
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Re: Position of fuse(s) holder in the wiring loom

Post by clive »

When working on the bike it is sensible to remove the fuse to the live side (positive or negative whichever is your choice) so negating any risk from spanners etc.
clive
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Re: Position of fuse(s) holder in the wiring loom

Post by aobp11 »

Matt you're right.
With disconnected live a spanner might create a terrible shortcut between live battery pole and vehicle chassis.

With disconnected earth a terrible shortcut would only happen in the rare situation that a spanner touches the live wiring (or battery pole) and the earth battery pole at the same time. A spanner between live wiring (or battery pole) and vehicle chassis does no harm at all. A spanner between earth battery pole and vehicle chassis would put the battery voltage back on the wiring, without problem when no short from live wiring to vehicle chassis is present.
Another point is that on some vehicles you needed a spanner to undo the cable clamp from the battery pole. Undoing the live side is risky when the spanner could touch the vehicle chassis.

Albert
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Re: Position of fuse(s) holder in the wiring loom

Post by SPRIDDLER »

During my apprenticeship a chap sustained a severe burn on his wrist when his expanding metal watch strap shorted a Jag's battery post to the battery retaining bar.
On my first day I was told never to wear a watch, tie or scarf even though back then (1961) the unheated workshop was very cold and draughty.
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