1987 F-150, 174,000 miles, 4.9L, C-6, owned for 7 years

I am having trouble getting my horn to work. The stock steering wheel has been changed to an aftermarket Grant steering wheel with adapter. The adapter has two black wires that connect to the horn button on the steering wheel. One wire is positive and one wire is negative.

While I was troubleshooting with the ignition key in the off position I touched the + wire to the steering wheel adapter and the horn works. If I touch the + wire to the - wire coming from the adapter the horn does not work.

With the ignition key on I touched the + wire to the steering wheel adapter and the horn does not work. I touched the + wire to the - wire coming off the adapter and the horn does not work.

The voltage of the + wire with the key off is 12.4 volts grounded to the - wire or the steering wheel adapter.

The voltage of the + wire with the key turned on is 4.6 volts grounded to the - wire and 9.8 volts grounded through the adapter.

What do you think my problem is?

 

Did you hacksaw off the stub?
Did you cut off the exteranl part of the spring?
If your grant wheel is painted, did you use the aluminum disc?

 

I did not hacksaw off the stub.
I did not cut off the external part of the spring.
My wheel is painted and yes I used the aluminum disc.

I followed the directions provided by Grant.

Any ideas???

 

I don't mean to be a wise-*** but reread the directions for Ford and two wire systems.
Which grant wheel did you get, the classics is different than the newer models like the signature. Let me know and I might be able to tell you what all needs to be done.

 

I figured out my problem today. Bad ground in the main harness. I created a new ground and now my horn works. It has been a long time since I had a horn! By the way I have a signature series wheel and followed the directions. The bad ground through me off because I assumed everything was perfect prior to installing the new steering wheel. Thanks for the help.

 

Congrats! But odd that you didn't have to cut off the external spring on the horn button, I thought this was mandatory for all the wheels in this line....
Alls well that ends well :-)
Tim

 

Hmmm. Mine doesn't have any spring on the horn button. Just two prongs to receive the positive and negative wires. I emailed Grant about the problem and my truck is "special" because I have cruise control. The wiring is diferent than other trucks. Take it easy.

 

I have a '91 F150 and the horn works when the key is off, but not when it is on. The cruise works sometimes, but the function buttons seem crossed up. When the key is off there's 12v or better at the horn and crusie controls, but when the key is on, it drops to about 6v. I suspect a bad ground, but don't know how to run another. Any tips?