Hi guys,

I am looking to install accessory lights that draw 8 Amps a pair and want to use the accessory switch. The accessory line itself has a 15 A fuse so it can handle this load without using a relay. But, if the accessory switch is rated for lass than 8 amps I may have a reliability problem eventually.

Does anyone know the rating of this switch?. Ultra 08. Thanks

 

When most electrical circuits are designed they are then fused protected for at a value of 80%.

So assuming that they followed the rules, the weakest link(other than the fuse) in the circuit on the bike has a true rating of 18 amps at 12 volts.

You should be able to wire them in directly to the circuit and use the switch as a control, but I would add the relay controlled by the switch, which would draw less (normally around 2amp) in case down the road I wanted to add more to the circuit.

 

bottom line is you need to use a relay... just my .02 cents

 

Put this in the FWIW category since I'm no electrician or tech. However, I have installed the HD fog lamps and Motolights on my bike and both provide power to the lights from the battery directly with an inline fuse , and use a relay to control the on/off function. The Motolights come with a plug compatible with the HD accessory plug under the seat for the on/off function to be controlled by the accessory switch on the bike.

I don't have the amp rating for these lights, but they are probably similar to what you are considering.

 

Agree totally with this response. I would use a relay for a number of reason, not least of which is stated above, but also:

Is the 8A continuous or in rush? In rush (i.e. at switching point) may well be considerably higher

If you arc the contacts during switching they pit and corrode and the switch becomes unreliable. For a negligble cost and no aggrevation you can change the fuse, whereas changing the acc switch would be a pain.