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A/C - Auto Temp Control Blower Relay Service Kit

Bulletin No. T 85-26
File In Group 1
Number 19
Date Nov. '84

SUBJECT: AUTO TEMP CONTROL BLOWER RELAY SERVICE KIT

MODELS AFFECTED: 1976-1980 FLEETWOOD, DEVILLE, BROUGHAM AND LIMOUSINE 1977-1979 ELDORADO AND SEVILLE 1976-1984 COMMERCIAL CHASSIS


Some Cadillacs equipped with ATC systems may experience relay center damage when the blower relay (also called A/C or auto relay) malfunctions.

If the damage to the relay center will not allow the replacement relay to function properly, service kit (P/N 12043552) should be used to correct this condition. This kit includes a connector pigtail, with relay (P/N 12034544) installed, and four crimp splices. This kit may also be used to replace a malfunctioning blower relay, where no apparent relay center damage is noticed. When installing this service kit, follow the instructions below.

Installation Instructions for ATC Blower Relay Service Kit

1. Disconnect negative battery cable.

2. Cut the four (4) wires going to the blower relay as close to the relay center as possible.

3. Strip, solder, splice and tape these wires to the service kit jumper wires according to the following table:

Kit Jumper Wire Car Harness Wire

Brown Brown or Yellow
Light Blue Light Blue
Orange Orange or Red
Orange/Black Orange/Black or Orange

NOTE: For 1977-1979 Seville, the Orange jumper kit wire should be connected to the Black/Red car harness wire.

4. Secure relay in a position to avoid rattles.

5. Reconnect negative battery cable and evaluate system for proper operation.