1988 F series 3/4 351 Horn relay location
 

Can anyone tell me where the horn relay is located I have looked its not near the horns. I cant get the horn to work. Just to let you know what I checked the horn is good and when i touched the horn pad I did not hear any clicking. I looked at a wiring diagram it said that there was a horn relay made for the model with cruise control and one without . The horn did work for about 2 minutes when I was driving down the road then it died. I would like to find the relay just to be able to rule it out, any help is appriciated thanks fellas

Moved to correct forum

If you have cruise control there is a relay for the horns.
If you don't have cruise control, there is no horn relay.

For the circuit that has cruise control, the horn relay is located behind the instrument panel right hand side of steering column next to the Speed Control Amplifier. The Speed Control Amplifier is a small metal box with two connectors going to it. A Green connector and a Gray connector. The Horn Relay should be around that area. I've never seen it so I don't know if you can see it from under the dash or if you have to pull the dash cover.

The Horn Relay will have 3 wires going to it. Yellow/Light Blue which comes from 30 amp fuse number 16 and is hot at all times. There is a Yellow Light Green wire which goes to the Horns.
So when you press the horn button on the steering column, a Dark Blue wire is grounded which closes the relay and 12 volts is passed from the Yellow/Light Blue wire to the Yellow Light Green wire.

You can tell if the 30 amp fuse is blown by seeing if the the cigar lighter works. That 30 amp fuse also provides 12 volts to the cruise control and the fuel injector cooling motor mounted on the passengerside plastic wheel well housing.

F150xlt
Thanks for the response I was looking at a electrical schematic and it showed a horn relay for the cruise and one without cruise . They also listed two at the parts shop so I purchased it but after looking around and I do all my own work I tend to agree with you there is none the problem must be in the steering wheel the pad or below the wheel I will keep trying im not one to install horn buttons couldnt live with it so thanks again my friend

If you don't have cruise control the circuit is very simple.

Fuse #16 which is 30 amps. and is hot at all times goes to the Horn switch on the steering column. The wire is Yellow/Light Blue. When the horn switch is pressed, 12 volts passes thru the switch on a Dark Blue wire going to each horn. It looks like the horns use the frame as ground.

Fuse #16 (12 volts)---> horn switch> horns

The horn pad on the steering column is held on by some allen screws on the back side of the pad. Real easy to take the horn pad off. Just remember 12 volts is always present on the Yellow/Light Blue wire. If no 12 volts, the fuse is blown.