My old horn in my 1990 F150 died and to pass inspection the horn is one of the things that need to be fixed. So, I bought a new universal horn by Hella but the intructions supplied are very poor. I am not sure where the old horn is under the hood. I need to figure that out before I can install the new one. Any help would be appreciated.

 

Alright, I have tried to find diagrams and search the internet for help. I have found nothing. Please, how do I replace the old horn?

 

those things are usually under or near the headlights.

 

I found them. Now I have a new problem. The factory horns have one wire connector on each horn and the Hella universal horns have two on each horn. I could always buy a couple factory horns but then I would of wasted my money on these Hella horns. Hella should of spent more time with their english directions than printing them in several different languages.

 

One is power, one is ground. The power goes to the horn wire, and the ground can be screwed to any metal area, such as the horn mounting bolt.

 

This is the problem I am facing. For each horn there is only one wire. I think you might be right Sean but here is a picture just incase I confused anyone on what I was trying to say/describe.

 

The factory horn is grounded through the bracket. The Hella horn might be or maybe not. Put the horn in and hook the power wire to either tab. See if it works. Then try the other tab and see if it works. If it doesn't work with only a power wire then the other will be ground, but if it works with either tab hooked up then it's just a feed for multiple horns. If it does need a ground I'm pretty sure that either one can be used for power or ground. Like a power window, reversing ground changes the direction of the motor.

 

I'm thinking that it will need to be grounded because I have tried hooking the power to either one and it doesn't work. Does it matter what gauge wire I should use for the ground?

Anyway, I will try what you have recommended and reply tomorrow with the results.

 

Use the same gauge wire for the ground as the power. Remember when you tested it the bracket needed to be touching ground for it to work if it's grounded through the bracket.

 

use a 18 or 16 gauge wire. the power window is kinda wierd for a referance, id of said like a light bulb...but same difference, and i agree, one is power, one is ground, the factory is internally grounded