Non working horn

jd

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#31
Just for me, I don't see any risk of triggering an airbag deployment by installing a UHB unless you accidentally feed a signal into the airbag system. The risk I was thinking of, was that if you don't somehow disable the Horn Button Pad part of the Airbag when you connect the UHB, then you leave the Pad (if working) able to sound the Horn, in addition to the UHB.
I can't read all the words, and every terminal number, in the diagram on Page1. Somebody correct me if I don't have this right:
1. The 30 terminal of the Horn Relay is always Hot via the 20A fuse
2. Input from Battery to Horn Relay COIL (can't read the terminal number, it's either 85 or 86) is HOT from Battery and NOT fused
3. Horn Relay COIL needs a Ground to operate, closing 30 to 87 and on to the Horns. Gets this Ground from ECM to Horn Relay 86 or 85 (again I can't read it)
4. So... Horn Button sends a Ground signal to the ECM Horn Relay Center through the Clock Spring. ECM Horn Relay Center sends a Ground signal to the Horn Relay on 86 or 85. Since 85 or 86 is already HOT, the Coil connects 30 (hot through 20A Fuse) to the Horn through 87
If it was mine I would
1. Determine if 85 or 86 on Horn Relay is HOT using Meter or Test light. For now, assume 85 is Hot an 86 gets the Ground Signal
2. Disconnect Battery and wait an Hour
3. Disconnect ECM Ground Signal from 86 and Battery Hot from 85
4. Connect 30 to 85. This provides power to the Relay Coil
5. Connect 86 to one side of UHB
6. Connect other side of UHB to Ground
7. OEM Horn Button can't sound the Horn via Clock Spring and ECM because ECM is no longer connected to Horn Relay
8. UHB WILL sound Horn because it sends a Ground to Horn Relay Coil 86 and 85 is already Hot from Horn Relay 30 and 20A Fuse
9. Horn sounds because Horn Relay Coil connected 30 to 87

That said, the ECM is a picky critter. I don't know if it has a way to know it's no longer in touch with the Horn Relay Coil and will set a Code, turning the Check Engine Light/CEL on. I doubt it but ECM stuff is above my paygrade.

If you don't want to cut wires going into the Horn Relay Socket, you can get a wired Relay Socket. Put spade terminals on the Socket's wires and push them into the relay contacts in the Socket.

Come to think of it, do THIS instead
1. Get a Wired Socket.
2. Connect Wired Socket Wires for 30 and 85 together
3. Plug Terminal on those connected wires and plug into 30 in the original Socket
4. Put a Terminal on Wired Socket 87 and plug into 87 of original Socket
5. Put a Terminal on new wire to UHB and plug into 86 of original Socket
6. Ground other terminal of UHB
 

jd

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#32
Picture might help. Here's a relay with a wired socket
. By using a wired socket, you don't have to cut any wires, and you get a place to wire your UHB to.