Engine Overheats, DTC F49 (Cooling Fan Runs Backward)
90cadillac11Bulletin No. T-90-103
File in Group 8
Number 119
016201
Corp. Ref. No.
Date Aug. 1990
SUBJECT: ENGINE OVERHEATS; BCM CODE F49
MODELS AFFECTED: 1990 DE VILLES AND FLEETWOODS
Some 1990 DeVilles and Fleetwoods produced prior to VIN 347520 may experience an engine overheating or BCM code F49 due to the left (driver's side) cooling fan running backward during slow speeds in high ambient temperatures. The cooling fan should draw air from the grille through the radiator. Miswired fans will push air from the engine compartment out through the radiator.
Figure 1 - Incorrect Wiring:
The cause may be a miswired resistor harness for the left cooling fan. Refer to Figure 1.
To repair this condition obtain the proper terminal removal tool from J-38125 Terminal Repair Kit and perform the following procedure:
1. Disconnect the two-way connector at the left cooling fan motor.
2. Unseat the terminals in the two-way connector cavity A and B
3. Reinstall the terminals in the two-way connector so that:
^ the wire in cavity A is connected to the resistor block.
^ the wire in cavity B is connected to eavity C of the three-way harness connector.
Figure 2 - Correct Wiring:
The jumper should appear as in Figure 2 when completed. If the engine overheating condition or BCM codes still exist after correcting the cooling fan condition, refer to symptom diagnosis in Section 6B of the 1990 DeVille/Fleetwood Service Information Manual or to Section 8D as appropriate.
For warranty purposes use Labor Operation N6270 at .2 hour.