Hi, I understand that some of the loud pneumatic horns could draw up to 20A of current. How do one wire them safely? I've heard somewhere that the crf250l original horn uses relay. Is that true? If it is so, is the power circuit to the horn connected directly to the battery, or is it going through one of the fuses (and which one). In summary, my question is: is it ok to connect a new loud horn directly to the old horn leads, or do I have to use relay on the horn switch, and create a separate power supply circuit to the horn directly from the battery terminals (and perhaps include a separate 20A fuse in it). Cheers!
Just had a look at my wiring diagram in the workshop manual and there is no horn relay, A shared fuse supplies a wire to the horn switch then to the horn and return to Earth. I would suggest a micro relay of a high enough current capacity for your new horn, connect the old horn supply to the relay for trigger purposes, run a suitable fused wire off the battery for the new horn supply, common up the return points somewhere convenient on the negative earth side, If you want a schematic just repost or PM me
Is that the wiring diagram? I'm learning how to read it (especially the tables at the bottom...)? This is probably for 2012 model, not 2017, but I'm not sure how different the wiring is.
hi, sorry for the delay in replying. It's a 10 Amp Fuse (don't forget it shares a load, it's not just for the horn) To follow the wiring, Locate the horn at the top left of your diagram, and trace the wiring. one wire will lead to a junction box then to the frame ground, the other wire will lead to the horn switch (in the dotted box on the lower left of you diagram) then follow it through the switch, this goes via two joint points (shown as dots) then down to the fuse box on position 2, just under the fuse box on the wiring diagram there are the designations and fuse sizes shown in a short table. I've added a rather poor image of part of my wiring diagram but it does show the relevant parts ( CRF250 L & M Europe )
