Need help troubleshooting horn problem
Need help troubleshooting horn problem So I bought my car last year with a non-functioning horn (I realized it didn't work after I hit the road), so I decided to get it working. Here's the deal- fuse is good, and when I try to use the horn through the steering wheel, I can here the relay activate. But using a multimeter, I'm seeing no voltage on the connector with the horn activated. So I'm guessing there's a problem somewhere after the relay/fuse. Does anybody ave any suggestions, or maybe have seen this before? Thanks for any help before hand.
Joined: Nov 2003
Posts: 11,328
Likes: 344
From: Jacksonville, FL (originally from Toronto Canada)
Test the relay. You'll find it in junction box #1 under the hood. It will have two orange wires, a black wire, and a dark green wire. The two orange wires both come from the same MiniFuse in the junction box. The black wire goes to ground through the horn switch in the steering wheel and through the BCM (for the keyless entry/alarm notification). The dark green wire goes to the horns.
Check first for battery power on both orange wires. If there's no power, double check the fuse. Fuses can look fine but still be blown so either use a tester or replace with a known good fuse.
Then ground the black wire and see if you get power output on the dark green wire. If not, replace the relay. If you get output on the green wire then you know the relay is okay so the problem must be either with triggering the relay or dead horns (or possibly some problem with the wiring between the relay and the horns).
To test the switch, disconnect the relay and test for ground on the black wire when the horn switch is pressed or the keyless entry is activated. If these switches/triggers provide the proper ground then the problem must be with the horns. Dead horns are not an unusual problem because of the mounting location leading to lots of water getting in them.
Check first for battery power on both orange wires. If there's no power, double check the fuse. Fuses can look fine but still be blown so either use a tester or replace with a known good fuse.
Then ground the black wire and see if you get power output on the dark green wire. If not, replace the relay. If you get output on the green wire then you know the relay is okay so the problem must be either with triggering the relay or dead horns (or possibly some problem with the wiring between the relay and the horns).
To test the switch, disconnect the relay and test for ground on the black wire when the horn switch is pressed or the keyless entry is activated. If these switches/triggers provide the proper ground then the problem must be with the horns. Dead horns are not an unusual problem because of the mounting location leading to lots of water getting in them.
