The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Lucas, Ignition, Charging, Electrical => Topic started by: old PJ on 29.12. 2007 20:26
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Hi all i have put the battery in the bike today and i was thinking about a inline fuse holder and a fuse of about 10 amps is this ok to do and will a 10 amp fuse be ok . I have one of them plastic inline car push fit fuse holders to put inline .
Thanks
Old PJ
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This is a more than good idea, can save a lot of troubles, and costs next to nothing. I can't understand really why som fuse was not standard since the invention of the battery.
I have been using an 8 amp fuse since I got the bike. And it did find it's use, blown a few times, trough shorts that happened while riding, and while doing repairs without taking the time to unplug it.
e.
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If you're running 12 volts 10 amps or less might be OK - but if you're on 6 volt IMHO and experience, you'll need more to allow safely for the surge when you turn the headlamp on. If, for example, you're running a 36 watt bulb, plus tail etc lights, say 40 watts plus all told, then that's nigh on 7 amps constant - but far more more in 'surge current' when you first hit the switch and the filament warms up. The fuse might take it, or it might not. After a couple of failures with 10 ampers, I've gone for 20 amps on my 6 volt bike - it'll blow well enough if there's a fault, but doesn't plunge me into darkness when I turn the headlight on or swap from main to dip beam - a constant source of possible surges with the traditional switches employed. Even with the bare glimmer of 25 watt bulbs, which are as much use as a bedside candle to a blind man, 10 amps can blow. Max surge can, I'm told, amount to three times rated requirement - so for 25 watts plus 5 watts tail plus 2 watts speedo - 32 watts, that's 6.33 amps, which could become way more than 10 amps for a long-enough millisecond.
With the 12 volts conversion installed on another bike, I use household 13 amp fuses (notional load 156 watts) because I have gazillions of old plugs with them in. Modern blade fuses are fine, so are the old spring-loaded cylindrical in-line jobbies, although they need the blobs of solder/tin that touch each end of the fuse to be clean - and cleaned periodically, especially in winter. One thing's for sure - a bike without at least one properly fused circuit is a hazard waiting to go bang - especially if the wiring is not accessible and rippable-out when things start to sizzle! Hope that helps, Groily
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I'll correct my post above, it's a 10 A (red) flat car-type fuse. Suppose they are quite slow-blowing and can take some short surge. No problems in use, 6v, with a 35w halogen front. As Groily writes, a total short will blow a quite larger fuse as well, long before any harm done to wirings or components.
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Yes Fuses are a must have *ex* Cant remember what I have on the Red A10 and have not looked under the seat of the Blue A10 so I dont know if there are any there. One thing I know is another must have.... and that is making them accessable for when they do blow. Mine is wired into the tool box just beside the regulator so I dont have to unscrew and remove the seat, how many times have I had to do that ???? dont ask.
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I can only agree with the others. Even if your bike is otherwise totally original as it left the factory you should regard a fuse as an essential part of the wiring. It is hard to understand how the bike manufacturers were blind to this logic but it is a very simple defficiency to rectify.
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Just out of interest, where abouts in the wiring harness are people putting their fuses? I would have thought that the obvious place would be between the positive terminal of the battery and its earthing point on the frame, but does anyone have any better ideas?
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I fit the inline type fuse holder, as used on car radios and put it in the negative wire from harness to battery.
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I am a bit anal about fuses.
Usually I fit 3
On each side of the battery ( 15A ) and one on the feed wire from the regulator to the light switch ( 20A ).
I first started using the big clunky "fully water proof" marine jobs but getting a good splice into the loom was not easy.
Now I am using these "semi waterproof" ones with much thinner wires that will fit nicely into standard crimp terminals.
The internal connection is via a standard crimp on spade so if you like you can cut the original wires and crimp them into the fuse holders and keep the original colour codes.
For many years I have been doing it this way.
(https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fi177.photobucket.com%2Falbums%2Fw205%2Fbsa_wm20%2FWiring%2520Upgrade%2FBattery_with_plug.jpg&hash=82bee3faca6c5bbc4a843354e5ea031ae946e1da)
The plug is fitted to the battery and then the terminals are painted over with liquid electrical tape.
(https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fi177.photobucket.com%2Falbums%2Fw205%2Fbsa_wm20%2FWiring%2520Upgrade%2FDCP_3277copy.jpg&hash=728b5b2128c8f69c516d7490387a998e58be6b16)
The other side of the plug goes to these fuses which I have found to be perfectly suitable. You can cut a piece of steel strip to fit into the gang slot to mount them on your bike.
(https://www.a7a10.net/forum/proxy.php?request=http%3A%2F%2Fi177.photobucket.com%2Falbums%2Fw205%2Fbsa_wm20%2FWiring%2520Upgrade%2FDCP_3276copy.jpg&hash=5fbcd026c09875aad606a85beb4cceb65cdbddbc)
The 3 fuses ganged together
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I was looking for something else and came across this, but figured I'd give this a trot; a few names I was familiar with when I joined up, but haven't seen for a while *????*
Back on track, I have fuses where fuses don't normally go after dark *eek*
Trev those are the batteries I had been using , but can't get them anymore- well unless they had a new delivery *????* President sold out to Lion Battery up here
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A fuse in the battery earth lead is useful when you set a spanner down so it touches the battery live terminal and a bare metal part of the bike.
Or when the screwdriver you're using to attach the live lead to the battery touches the battery box.
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inline blade fuses 10-25 amp with a trip and re set button on bay£1-94p item 141763252823
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I like the look of those. I blew 1/2 dozen normal ones looking for a short.
Cheers
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While looking for a short, put a small bulb in circuit.
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hi guys, yes fuses are a must so i redesigned the wiring and fused everything,cheers
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Nice job.
We cheat and use 2in 6 out or 2 in 4 out fuse boxes to get rid of those 4 way & 6 way bullets that always break
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hi guys, this is my wiring diagram for anyone who is interested,cheers
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hi guys, this is my wiring diagram for anyone who is interested,cheers
Nice to know KP, saved an image, but likely won't need it *wink2*
inline blade fuses 10-25 amp with a trip and re set button on bay£1-94p item 141763252823
I'm trying to figure how many of these I need; seems I have a knack for blowing fuses... while out the other night on a fuelup/food/beer/entertainment trip, I realised my brake light wasn't working, but it was earlier. The fuse was blown, so changed it, all good on rear brake, but blew on front brake *conf*, so blew a few more *pull hair out* .
When I was messing with the light switch, for some dumb reason I pulled off the switch/ammmeter panel, and getting dark, jammed it back on in a bit of a rush- I knew that at the time, but hoped it'd be ok *bash*- it wasn't... all good now
What I'm saying is, sometimes fuses blow for no apparent reason and having a re-settable fuse won't fix a problem, but it will save a lot of *pull hair out*, *good3*
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I fit a 25 amp contact breaker; can be reached whilst on the bike. Never have had to, thank goodness!
Richard