Pre-1997 Models

1988 F150 horn/relay switch location

  #1  
Old 02-06-2011, 10:42 AM
patdog's Avatar
Junior Member
Thread Starter
Join Date: Feb 2011
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
1988 F150 horn/relay switch location

Can someone tell me exactly where the horn relay switch is located? I have found several older searches saying it is anywhere from above the accelerator pedal to under the hood to behind the glove compartment. I have a replacement relay but cannot for the life of me find anything that looks like it inside engine compartment or underneath the dash. The 30A fuse is good for the horn/cigar lighter/speed control etc. Just hear clicking noise when horn pad is pressed. Just bought replacement horn but the one that was on it was fairly new and had been added at a repair shop. thanks
 
  #2  
Old 02-06-2011, 12:07 PM
russo2's Avatar
Senior Member
Join Date: Jul 2010
Location: Pennsylvania
Posts: 1,253
Likes: 0
Received 0 Likes on 0 Posts
If the relay clicks, it works. Look at your horns and wiring to them.
You could always pull the horns out and hook em to the battery and test them... but beware if you do that and they do work. You might **** yourself.
Or get out a test light and start tracing wires. I'd start from the horns n go backwards.
 
  #3  
Old 02-06-2011, 01:20 PM
Steve83's Avatar
Senior Member
Join Date: Nov 2006
Location: Memphis, TN 38135, USA, Earth
Posts: 5,495
Likes: 0
Received 7 Likes on 7 Posts
The horn switch is located on the hub of the steering wheel.

The pre-'92 horn relay is under the dash, near the cruise control servo above the gas pedal, and it's an old Ford-style relay. You probably got a Bosch-style relay, right? Look at these pics:



But russo's right - if it's clicking, it's probably fine. I bet those "new" horns are bad, or their wiring has come loose. If you paid the shop to install them, take it back & complain.
 
  #4  
Old 02-06-2011, 02:42 PM
patdog's Avatar
Junior Member
Thread Starter
Join Date: Feb 2011
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
Thanks for the tip russo. Hooked horn to the battery and it worked. So I guess its the wiring. The two wires that go to the horn merge into a plastic wrapped bunch of other wires. Do I try to unwrap and get them separated from the other wires then trace it back as far as I can? thanks for your expertise. I appreciate you taking the time.
 
  #5  
Old 02-06-2011, 02:49 PM
patdog's Avatar
Junior Member
Thread Starter
Join Date: Feb 2011
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
Steve. That picture you posted looks like its taken under the hood not under the dash. The brown thing plugged into the green thing with wires coming out looks like the part that I got from NAPA. I may be getting closer.

If I need to test the wiring, what kind of wiring tester should I use? Sorry if I that's a dumb question. I have one that's like an ice pick with a clip at the end of a wire. Thanks for your very detailed reply. The clicking sound of the relay sounds like its coming just below the dashboard above the steering wheel. But I guess it's not that the problem I shouldn't worry about it right? I appreciate your time.
 

Last edited by patdog; 02-06-2011 at 02:55 PM.
  #6  
Old 02-06-2011, 04:24 PM
patdog's Avatar
Junior Member
Thread Starter
Join Date: Feb 2011
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
Finally. I found the relay and replaced the switch. Still now horn. I know you told me it wouldn't but since I had located it I went ahead and changed it.

Now for the wiring. I found that the two clips that attach to the horn are actually a split from the same wire. There were no breaks in the wire but the tape that wrapped the junction was brittle and in pieces. I cut off the clips and used two new clips to see if that would work but it didn't (I grounded the horn first). Burnt out on this for now. Will get back on it later. thanks again for your help
 
  #7  
Old 02-06-2011, 04:43 PM
russo2's Avatar
Senior Member
Join Date: Jul 2010
Location: Pennsylvania
Posts: 1,253
Likes: 0
Received 0 Likes on 0 Posts
I would first use a test light, the 'ice pick with a clip on the other end' and see if you even have power, of course you will need someone to hold the horn button or else you wouldn't have power to the wires anyway. If they do have power you can get out a meter and see if you are getting enough power through the wires.
If you don't have power you may be better off tracing the bundle of wires to the relay I suppose it would be and then just run all new wire. If the wire is broke in one place it's gunna break somewhere else too.
 
  #8  
Old 02-07-2011, 11:04 AM
patdog's Avatar
Junior Member
Thread Starter
Join Date: Feb 2011
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
I will test the wire where it comes out of the relay switch. If that has juice when the horn pad is pressed I am going to just splice in a new wire and run it to the horn and be done with it. Thanks Russo. nice pic of your truck. I had to show my wife - "look baby it's a meat wagon just like mine all dirty too. she just smiled and said oh good, I'm sure his wife is just as excited as I am." LOL
 
  #9  
Old 02-07-2011, 11:11 AM
russo2's Avatar
Senior Member
Join Date: Jul 2010
Location: Pennsylvania
Posts: 1,253
Likes: 0
Received 0 Likes on 0 Posts
Thanks, the picture is messed up due to the panoramic stuff and it made the body lines all messed up.
Wife.. Not so much, I'm 18 haha. My girlfriend pretends to care though. She really hates when it's dirty.
The day it got that dirty was the day my horns got ruined. I got my truck completely sunk in about 4 feet of muddy water and it got everything clogged up. My horns only work when the mud inside em thaws out.
Sure had fun though.
 
  #10  
Old 02-07-2011, 06:00 PM
Steve83's Avatar
Senior Member
Join Date: Nov 2006
Location: Memphis, TN 38135, USA, Earth
Posts: 5,495
Likes: 0
Received 7 Likes on 7 Posts
Originally Posted by patdog
That picture you posted...
...is a linked thumbnail. Click it. The captions explain what's being done (and you should do it), but the main reason I posted it was to show 2 possible types of relay. There's one more that Ford used, which has a triangular rubber 3-pin connector.
Originally Posted by patdog
I found the relay and replaced the switch.
The horn SWITCH is one thing; the horn RELAY is something entirely different.

If you want to upload pics of your truck or the stuff you're working on, it's free: just read this thread.
 
  #11  
Old 02-08-2011, 08:07 AM
patdog's Avatar
Junior Member
Thread Starter
Join Date: Feb 2011
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
Sorry I meant changed the relay. I will take some pics and upload them when I get it working. thanks steve for the replies.
 


Thread Tools
Search this Thread
Quick Reply: 1988 F150 horn/relay switch location



All times are GMT -4. The time now is 06:43 AM.