INSUFFICIENT A/C COOLING AT IDLE

INSUFFICIENT A/C COOLING AT IDLE

VEHICLES AFFECTED: 1985-1986 Devilles, Fleetwoods and Fleetwood Seventy-Five Limousines

This Bulletin Supercedes Bulletin 85-1-131 which should be destroyed.

Some 1985 and 1986 Devilles, Fleetwoods and Fleetwood Limousines may experience insufficient air conditioning cooling while driving at low speeds in high ambient temperatures and high humidity. This condition may be caused by insufficient air flow across the condensor.

To correct this condition, a new BCM Prom (refer to chart below) and cooling fan shroud (P/N 22040876) have been released. The BCM Prom was a mid-year production change on 1986 Devilles after broadcast number 311366 and 1986 Fleetwood Limousines after broadcast number 311474. To install these components proceed as follows:

BCM Prom Installation:

Check the BCM Prom calibration using F.8.0 BCM data display diagnostic parameter P.3.1 (BCM Prom I.D.). If the BCM Prom I.D. does not match the value listed in the chart below, the Prom should be replaced with the part number shown. After verifying or installing the Prom* proceed with the "ECC System Check" outlined in the Service Information manual.

BCM Prom For Improved A/C Performance

APPLICATION PROM I.D. BROADCAST CODE PART NUMBER ----------- --------- -------------- -----------

1985 FWD Deville and Fleetwood with 4.1 4-8 Engine 14 BRY 1228026

1985 FWD Deville and Fleetwood With 4.3 Diesel Engine 114 HRZ 1228O24

1985 FWD Fleetwood "75" Limousine 204 HSA 1228025

1986 FWD Deville and Fleetwood with 4.1 V-8 Engine 20 AAPT 16062532

1986 FWD Fleetwood "75" Limousine 220 AAPU 16062546

Fan Shroud Installation

1. Disconnect left fan Electrical Connector.

2. Remove and discard the four bolts fastening left fan brace to radiator.

3. Remove fan assembly. Discard four isolating washers Figure 1.

4. Remove fan blade from shaft, and fan motor from brace. Discard brace.

5. Attach fan motor to shroud (P/N 22040876) and reinstall fan blade.

6. Install fan shroud assembly to radiator using new bolts (P/N 20351035) Figure 2.

7. Reconnect fan electrical connector.

For warranty purposes, use the most appropriate labour operation and time from the Labour Time Guide.

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.