I own a Ford F150 XLT 1993. I need to know if the Horn is a Postive or Negative. I am attemping to put in a Car Starter. I was told by the company that this truck is Negative. I not sure how to find out. I have a voltage checker and when i use it on the Blue wire for the horn it light up until you honk the horn then it gose out. This sound like to me it is postive horn. Any help to understand this would be great.

Thanks

 

I'm about 99.9% positive it's a negative ground horn. Pull the wire off and check the voltage from the wire to a ground. When you hit the horn, if you have voltage at the wire, it's a positive horn system. (That sounds kinky, doesn't it?) :-)

-Joe-


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98 Explorer (Lemon Law Case in Progress)

'00 F-150, X-cab, 4x4, Lariat, Off-road, Trailer Tow, Holandia Sunroof, built 11/99 picked up 10/00!Clear Corners, Manik Stainless Steel 1-piece brush guard, Custom CB wiring, Uniden PC76-XLW CB radio with K-40 Magna-Mount antenna (for now), 1 set of 165 watt KC Daylighters (for now... more on the way) Custom switch mounting plate and overhead console.
List of planned mods: Clear tails, color matched trailer hitch with stainless steel ball, torsion bar tweak, bug deflector, spray in liner, and a tonneau of some sort...

93 Probe GT teal, OE rims painted to match, bone stock drivetrain.

 

100% sure is a negative ground. I replaced mine with air horns (now they do move out of my way ).