C4she won't Blow
Thread Starter
Pro
Joined: Oct 2004
Posts: 667
Likes: 10
From: New York
C4she won't Blow
Hi Guys I own a C5 and I usually post on that page but today I'm helping a friend with his problem.It all started with an antenna replacement a while back, we installed the new antenna and when we powered the radio it blew the radio fuse.
He owns a 1987 targa top. we disconnected the antenna replaced the fuse the radio now comes on we figured that out. now the horn doesn't blow. I checked for power at the both horn no power at the connectors I checked all of the fuses, I'm doing this with a test light.
Pulled the center console HVAC control to get to the horn relay. we replaced it although IT was good we found out at the end.
Tested the horn with the security system we opened the widow locked the car then unlocked it by sticking a hand inside and unlocking this way when you open the door the horn is suppose to sound. and it did.
we checked the horn button with Continuity and that is good. What are we forgetting to look at? Please help if you have any info it would be very appreciative
He owns a 1987 targa top. we disconnected the antenna replaced the fuse the radio now comes on we figured that out. now the horn doesn't blow. I checked for power at the both horn no power at the connectors I checked all of the fuses, I'm doing this with a test light.
Pulled the center console HVAC control to get to the horn relay. we replaced it although IT was good we found out at the end.
Tested the horn with the security system we opened the widow locked the car then unlocked it by sticking a hand inside and unlocking this way when you open the door the horn is suppose to sound. and it did.
we checked the horn button with Continuity and that is good. What are we forgetting to look at? Please help if you have any info it would be very appreciative
Race Director
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
Sounds like when you were under the dash, you pulled the horn wire going up the steering column to the relay. If the horn sounds with the alarm, it must be the wiring if it doesn't sound when you push the button on the steering wheel.
Melting Slicks
Joined: Aug 1999
Posts: 2,240
Likes: 42
From: Baltimore, MD USA
Tested the horn with the security system we opened the widow locked the car then unlocked it by sticking a hand inside and unlocking this way when you open the door the horn is suppose to sound. and it did.
we checked the horn button with Continuity and that is good. What are we forgetting to look at? Please help if you have any info it would be very appreciative
we checked the horn button with Continuity and that is good. What are we forgetting to look at? Please help if you have any info it would be very appreciative
The other black wire is grounded when you press the horn button.
You said you had continuity from the yellow wire under the horn button to the black wires of the horn relay?
When you remove the horn button from the steering wheel there is a yellow wire with a spade lug connector. If you ground the yellow wire, the horn should sound.
The other end of the yellow wire presses against a slip ring so the wire always makes contact even if the steering wheel is turned. The wire is pushed against the slip ring by a black plastic holder and a spring.
A very common problem is the black plastic holder cracks and the yellow wire no longer makes contact with the slip ring.
Here's a picture of the black plastic holder with an arrow pointing to where it usually cracks.
The second picture shows the yellow wire, spring and holder.
To remove the holder you press down on the black plastic holder and turn the holder so the two notched cut outs unhook/release.
Thread Starter
Pro
Joined: Oct 2004
Posts: 667
Likes: 10
From: New York
At the horn relay are two black wires. One black wire is grounded by the security system to pulse the horns.
The other black wire is grounded when you press the horn button.
You said you had continuity from the yellow wire under the horn button to the black wires of the horn relay?
When you remove the horn button from the steering wheel there is a yellow wire with a spade lug connector. If you ground the yellow wire, the horn should sound.
The other end of the yellow wire presses against a slip ring so the wire always makes contact even if the steering wheel is turned. The wire is pushed against the slip ring by a black plastic holder and a spring.
A very common problem is the black plastic holder cracks and the yellow wire no longer makes contact with the slip ring.
Here's a picture of the black plastic holder with an arrow pointing to where it usually cracks.
The second picture shows the yellow wire, spring and holder.
To remove the holder you press down on the black plastic holder and turn the holder so the two notched cut outs unhook/release.
The other black wire is grounded when you press the horn button.
You said you had continuity from the yellow wire under the horn button to the black wires of the horn relay?
When you remove the horn button from the steering wheel there is a yellow wire with a spade lug connector. If you ground the yellow wire, the horn should sound.
The other end of the yellow wire presses against a slip ring so the wire always makes contact even if the steering wheel is turned. The wire is pushed against the slip ring by a black plastic holder and a spring.
A very common problem is the black plastic holder cracks and the yellow wire no longer makes contact with the slip ring.
Here's a picture of the black plastic holder with an arrow pointing to where it usually cracks.
The second picture shows the yellow wire, spring and holder.
To remove the holder you press down on the black plastic holder and turn the holder so the two notched cut outs unhook/release.
At the relay I have two Pink wires and one Green black.
I grounded the yellow wire from the steering and the horn did not blow.
I checked all of the connection and it seems that when everything is in place and I try to push the horn the relay doesn't even click. so I'm thinking it may be a connection between the Steering and the relay. got to take a look under the dash. Guys thank you for the suggestions at least I know I'm looking in the right area. I will let you know how it's turning out. Thanks again and keep them coming.
Melting Slicks
Joined: Aug 1999
Posts: 2,240
Likes: 42
From: Baltimore, MD USA
The Pink wire provides 12 volts for the horn relay primary coil and the secondary contacts of the relay. When the relay is energized the 12 volts from the Pink wire passes thru the relay to the Dark Green wire which is connected to both horns.
The two Black wires are what energizes the relay when either of them is grounded.
It appears from the schematic, the Yellow wire at the horn switch turns in to a Black wire after the slip rings in the steering column.
