Quick question - Anyone know what size fuse is suitable for the M20? I'm not very electrically inclined. I'm still running a 6 volt system, but with two 5amp gel cell batteries in parallel (6 volts, 10 amps). I suppose wire gage is the limiting factor, but since I haven't burned any wires yet I'm not sure what fuse makes most sense. If it matters, I've got a 25/25 watt haolgen headlamp bulb, and currently an 18/6 watt incandescent tail light. Hoping to switch to LED tail light soon. Thanks!!!

Craig

Hi craig

If you have a total of 25w + 18w = 43w

Divide this by your battery voltage to obtain your current flow in amps

In this instance just over 7amps

I run the same bulb as you up front but an led backlight, i get away with a 3amp fuse

An led in the back makes a big difference

Maybe a 7amp fuse would do for you

Hopefully someone more knowledgeable can confirm

Best regards

Jo'b

email (option): Jonnyob1@googlemail.com

Hi Craig,
John was very correct. I just want to add few points:

25w+18w+6w (when back pilot and brake lights both on with the front light)
makes 49 Watts. The formula is P=I*V, so I(Amp)= P(Watt) / V(Volts)
so your total max current (assuming no speedo light and ammeter internal lights) is just over 8 Amps,
so you might want to consider a 10A min, or 15 Amp fuse.

The idea behind a fuse is to allow the system to run,
and burn only in case of extreme current abnormality, so value should leave some "spare".
Also you might need this 15Amp if your horn also runs on the same main wire, as it is about 4-5 Amps.

It is recommended to pass the (+) of the horn (assuming you have negative earth)
via a fuse, as it is the only electric component on the bike which actually has a supply of steady (+) all the time,
and only get ground when you press the horn button and earth it to the handlebar. (or you can fit a separate 5 Amp fuse only for the horn)

If you will fit a LED on your tail (I did it, and also replaced the “parking” (?) lamp in the headlight to some 40 LED lamp)
The difference is HUGE. The ammeter just Doesn’t move back..

Cheers,
Noam.

email (option): noam10@gmail.com

Perfect feedback guys, thanks!

Any tips on where to find the rear LED bulb? I've contacted 3 sellers and so far no one has a dual contact, offset pin, 6volt bulb that is suitable. Any suggestions would be great.

Thanks again-

Craig

Hi craig
Got mine from beck elektronica in netherlands
You will find a link on the website page
Mine is fitted to a convoy style light - combined tail & brake light
Best regards
Jo'b

email (option): Jonnyob1@googlemail.com

Hello Craig,

I ordered mine from

http://www.superbrightleds.com/

Takes some search, but it is there.
if you cannot find- let me know and I’ll look it up.

Important thing is that the 6V LEDs I got, were marked "AC", meaning it can work on positive or negative ground.
(LEDs usually care about polarity)

Another point is that you can order the tail light LED
in amber color, and that results in passing much more light through the red lens, which otherwise "swallows" allot of the glare.

Good luck,
Noam.

email (option): noam10@gmail.com

Thanks again to you both. I actually contacted Hans and he said he doesn't ship to the US or have english instructions. My M20 is a '46 civy too, so maybe it wouldn't fit. I am talking to Hans about a solid-state regulator though, which he is willing to ship to US. Go figure.

I also contacted superbright LEDs, but I didn't think to consider the "AC" models. Good to know! I actually assked their tech support specifically and they said they didn't have anything that would work for me, but maybe that person was wrong? I'll look again, but if you happen to recall which you ordered do let me know. Also, my civy could be slightly different than the WDs? 6v, offset pins, dual contact. BA15 base.

Craig

email (option): cpdoberstein@gmail.com

Hi Craig,

Superbrightleds has some really nice things,
But it is not the first time their thech’ support actually doesn’t know what they have…

In this link

http://www.superbrightleds.com/cgi-bin/store/index.cgi?action=DispPage&category=OTHER&Page2Disp=%2Fspecs%2F1156_57-x12-24V.htm

you will find:

1157 Dual & 1156 Single Contact LED Cluster Bulbs
15mm Bayonet base bulb for 6, 12, and 24 Volt Applications. 1157 (BAY15D)- Dual Contact and Dual Intensity. 1156 (BA15S) - Single Contact and Single Intensity.


scroll down to a chart, and you should be able to see 6V models.
The “11557-R19” VOULD BE 6V, red, 2 “filament” bulb.
Actually, all of the LEDs are on all the time, but the intensity is different.

It is also mentioned “No polarized bulbs for positive ground vehicles” beneath the photo,
But if you are running negative ground system, you do not really need this feature and it does not affect you.

You also have a technical draw of the bulbs below,
And small buttons “select product” on the right hand side of the picture on the top part.

This bulb has offset pins, as every dual intensity bulb should have,
In order to prevent one from insert it in 180 deg’ offset, result in mix of the high/low.

Good luck,
Noam.

email (option): noam10@gmail.com

Thanks again Noam, much appreciated!

email (option): cpdoberstein@gmail.com