Originally Posted by 16ACE27
When I installed air horns on my coach I tapped into the OEM horn wiring for the trigger signal AND used the relay for the air horns main power. This instituted a slight delay for the air horns but the OEM horns worked as before. This allows me to do short toots as required for signaling but if I lay on the horn button the air horns kick in for the blast that is sometimes needed for oblivious drivers.
That's exactly the way to do it.
It's also how you do auxillary lighting. Trigger is the stock light and aux has its own power.
Now a slight hijack:
Years ago I was admonished, but not ticketed, by a California cop due to my horn modification.
'horns are regulated by dB, go home and unplug that thing'
I went home, read up, and yes, horn dB was regulated by vehicle type.
I also read of a lawsuit where someone was startled by an 3xtra loud horn, over corrected, wrecked and won against the honker.
This story was all too many years ago to have any reasonable validity now what with the multiple front white light laws being ignored, the windshield height minimums being ignored etc.
Jc Whitney and all others used to have horn disclaimers in their ads.
Any input as to legality?