Forum

[Riggers]

One of these should do the trick. I fitted heated grips to my Yamaha TDM900 using one. http://www.ebay.co.uk/itm/FOG-RELAY-4-P ... 232b18b086

[Frosty]

Go to your local auto electrical parts outlet (once a Lucas in every town but alas no more so a little harder to find now) and ask for a 4 or 5 pin 12 volt automotive relay. You want a basic relay, some have a diode across the internal coil, you don’t want one of those.
If it’s a 5 pin relay (which are more common) ignore the centre terminal 87a. If it’s a 4 pin relay there won’t be a terminal 87a.
Ignition feed onto terminal 86
Earth to terminal 85
Battery feed onto terminal 30
Feed out to new accessories fuse box from terminal 87
Remember to use the correct wire size, check current ratings on your accessories. Volt drop won’t be an issue with a 12 volt system on a distance the length of a bike if you use the correct cable size.
I did this on my BMW for exactly the same reason. You will be amazed at how low the current draw is for the grips.
Your Auto Electrical outlet will help you with cable size. Or look for it on the net. Different cable types have different ratings, imperial, metric or thin wall.
Phil

[JTL]

Hi all... I too need to fit a relay to my Bullet. This will be for the headlight. After contemplating on the ac/dc conversion to full dc I have decided to do so. A real life experience and Norm convinced me on doing it, and with a relay triggered by the rear brake light switch feed (if understood correct). But I have only been able to source a 30A relay in the shops around me (the fuse is 20A). Will it be OK, or will it melt down the new circuit? If it's not OK, I will to use the eBay link above... Frosty, how do I determine the correct wire size for this new wiring? Can I just re-use the wires already there? I bought some 1 mm2 wire from our host to do another re-wiring job (LED blinkers, pilot light etc.); are they the correct size for the headlight too (55/60 watt)?.. Can some one answer Alan R's question. I would really like to know the answer... all the best Jacob

[Gwilly]

JTL the rating on the relay (30 amps) in your case is the current which can be safely switched and held by the relay contacts without creating damage to those contacts...

More than enough to switch on a 65 watt headlamp bulb... A simple sum would be watts divide by voltage = amps: So lets say 100 watt bulb divided by 14 volts (running engine) will equal
just over 7 amps to be switched... you have 23 amp spare capacity. A 12.5 amp rated cable would also be well within spec.. gwilly

[Bertie the Bullet]

Hi all, heading off to Maplin tomorrow for a relay and other electrical goodies the only thing I'm not sure about, when the relay spec quotes 12v or 24v is that the voltage required to switch the relay or the amount of voltage it can handle, or both ?

[Gwilly]

12 volts required to switch contacts, load will be in amps..

[JTL]

Thanks Gwilly, that's the info I need. Now I just have to buy a new reg/rec for the upcoming ac to dc conversion... Jacob