DIGITAL CLUSTER GOES BLANK OR SPEEDOMETER READ 188 W/HORN

SUBJECT: DIGITAL CLUSTER GOES BLANK OR SPEEDOMETER READS 188 WHEN HORN IS DEPRESSED (INSTALL HORN KIT)

MODELS: 1993 S/T WITH DIGITAL IP CLUSTER (RPO U52)

CONDITION

Some 1993 S/T trucks with RPO U52 Digital IP Clusters may experience an intermittent blank IP cluster or a reading of 188 on the speedometer display when the ignition is on and the horn is depressed.

CAUSE

This condition is caused by a voltage spike in the horn circuit when the horn is actuated.

CORRECTION

To correct this condition engineering has released two service horn kits that have built-in electrical suppression. Vehicles have been corrected in production after the following VIN'S:

Pontiac West P0513648

Moraine P2523127

Shreveport P8519090

SERVICE PROCEDURE

1. Disconnect and remove "F" note horn from the left radiator support.

2. Assemble "F" note horn and bracket from Horn Kit (P/N 10456443).

3. Install and connect the horn.

4. Disconnect and remove "A" note horn from the left inner fender.

a. T-Truck - Remove the oil filter. If equipped with an L35 engine, remove the air cleaner assembly.

5. Assemble "A" note horn and bracket from Horn Kit (P/N 10456328).

6. Install and connect the horn.

7. Reinstall the oil filter and remote air cleaner, if necessary.

8. Check and add oil as required.

SERVICE PARTS INFORMATION

Part Number Description QTY ----------- ----------- --- 10456328 Horn Kit "A" Note 1 10456443 Horn Kit "F" Note 1

Parts are currently available from GMSPO.

WARRANTY INFORMATION

For vehicles repaired under warranty, use:

Labor Description Labor Time Operation ----------- ---------- --------- N0200 Horn Assemblies, See Applicable Replace Labor Time Guide

S-Truck T-Truck

Add: With L35 engine and remote air cleaner.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.