For 1990-2009 cars

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 |

1. Disconnect the horn relay.
2. Connect a test lamp from UH electrical center 1 terminal E6 to ground.

Does the test lamp light?

--

Go to Step 2

Go to Step 8

2 | Connect a test lamp from UH electrical center 1 terminal E8 to ground. Does the test lamp light? | -- | Go to Step 3 | Go to Step 9
3 |

1. Connect a test lamp between UH electrical center 1 terminals E6 and F8.
2. Press the horn switch.

Does the test lamp light?

--

Go to Step 4

Go to Step 10

4 | Connect a fused jumper between UH electrical center 1 terminals E6 and F6. Does the horn sound? | -- | Go to Step 15 | Go to Step 5
5 |

1. Reconnect the horn relay.
2. Disconnect the horn.
3. Connect a test lamp from horn connector terminal A to B+.

Does the test lamp light?

--

Go to Step 6

Go to Step 13

6 |

1. Connect a test lamp from the horn connector terminal B to ground.
2. Press the horn switch.

Does the test lamp light?

--

Go to Step 7

Go to Step 14

7 |

1. Inspect the horn for a poor connection.
2. If the connection is OK, replace the horn. Refer to Horn Replacement .

Is the repair complete?

--

System OK

--

8 | Repair the open or the poor connection in CKT 1140 between UH electrical center 1 terminal E6 and Horn fuse. Is the repair complete? | -- | System OK | --
9 | Repair the open or poor connection in CKT 1140 between UH electrical center 1 terminal E8 and S168. Is the repair complete? | -- | System OK | --
10 |

1. Disconnect connector C216.
2. Connect a test lamp from UH electrical connector center 1 terminal E6 to connector C216 terminal G (steering column side).
3. Press the horn switch.

Does the test lamp light?

--

Go to Step 11

Go to Step 12

11 | Repair the open or poor connection in CKT 28 between connector C216 and UH electrical center 1. Is the repair complete? | -- | System OK | --
12 |

1. Test for an open in the BLK wires attached to the horn brush slip ring.
2. Test for contact at the horn brush slip ring.
3. For Chevrolet only, inspect for a clean and tight ground at the case of the horn switches.
4. For Pontiac only, inspect for a clean and tight connection at the inflator module.
5. If the above items are OK, replace the horn switches. Refer to Horn Switch Replacement - On Vehicle .

Is the repair complete?

--

System OK

--

13 | Repair the open in CKT 250 between horn connector terminal A and S112. Is the repair complete? | -- | System OK | --
14 | Repair the open in CKT 29 between horn connector terminal B and UH electrical center 1 terminal F6. Is the repair complete? | -- | System OK | --
15 |

1. Inspect for a poor connection at the horn relay.
2. If the connection is OK, replace the relay. Refer to Horn Relay Replacement .

Is the repair complete?

--

System OK

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