Some 1984 De Villes, Fleetwood Broughams, 1984-1985 Eldorados and Sevilles may have radio clock displays that remain on with the ignition off or the ECC system operating on continuous high blower with compressor clutch engaged. Either condition can be caused by conductive grease in a bulkhead connector.
Conductive grease may cause the radio display to illuminate by inducing voltage on circuit 93 of the wiper/washer system which feeds back through circuit 43 to the radio via the fuse block.
1. To verify that a vehicle exhibiting this condition has conductive grease, remove the 25 amp wiper/washer fuse. The clock display will turn off.
2. To correct this condition, cut circuit 93 wire from each side of the left hand bulkhead connector (CIOO). Run a jumper wire through one of the open connector cavities and splice the harness wiring to this jumper on each side of the bulkhead.
Conductive grease may also force the ECC system to operate on high blower during compressor clutch engagement. Voltage from circuit 204 to the compressor is being induced onto the blower speed control, circuit 976.
1. To verify that a vehicle exhibiting this condition has conductive grease, turn the ignition on with the engine off. Set the ECC control head for 60 DEG F with low blower. This will engage the compressor clutch. Disconnect the compressor cycling switch. The blower speed will slow down.
2. To correct this condition, cut circuit 976 from center bulkhead connector (C101). Run a jumper wire through one of the open connector cavities and splice the harness wiring to this jumper on each side of the bulkhead.
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.