Horn Problem

On my 98 Explorer, the horn blows when its switched off but will not blow when it is running. What could be the problem?

I think you need to start at the horn relay in the battery junction box. See if the relay coil has power to one half the coil with key on and key off. The other side of the relay coil receives a ground when the horn button is pressed. Make sure you have good ground to the switched side of the relay coil while someone holds the horn button down with the key on. If not, verify you are on the correct terminal by verifying it has good groun with the horn button pressed and the key off (horn honking).

If the relay has power and ground at the coil in both cases, make sure the contact side has constant power on the "input" terminal. It should have direct connection to 15 amp fuse number 10 in the battery junction box.

-Rod