1990 Ford F-150 Q&A
1990 Ford F-150 Question: How do i install a dual terminal horn with single terminal wireing set up?
Single wire horns get power and the body of the horn is automatically grounded. It sounds like the horn you have gets one terminal connecting to the power wire that was going to the old horn, the second terminal on the new horn needs to have a ground wire attached to it connecting it to ground/metal on the body. - patrick mannion