REDUCED A/C COOLING AT IDLE (WIRING MODIFIED)
REDUCED A/C COOLING AT IDLE
VEHICLES AFFECTED: 1986-1988 BROUGHAMS -----------------
Some 1986-1988 Broughams may experience reduced A/C cooling at extended idle or in city traffic in hot, humid climates. This condition may be normal. However, if an owner comments on reduced cooling under these conditions, the system wiring can be changed to enable recirculation mode sooner. This will increase cooling at idle.
To repair this condition the wiring system can be changed using the following parts and procedure:
Required Parts: --------------
1. A 5 ohm (NOT 5K ohm) and 2.2K ohm resistor with a minimum of 1/4 watt power rating, plus/minus 10% tolerance from an electronics store.
2. Eldorado and Seville outside air temperature thermistor, P/N 16047526.
3. A pair of 2.4 M (8 foot) long, 18 gauge electrical wires.
Procedure:
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1. Remove thermistor from housing by clipping thermistor's legs at housing.
WARNING:
Exercise care when removing thermistor to prevent damage to the yellow weather coating.
2. Disconnect negative battery cable.
3. Follow procedure outlined in Section 1C of the Service Information Manual to gain access to the in-car sensor. Disconnect in-car sensor connector.
4. Splice the 5 ohm resistor at one of the two Circuit 909 wires, refer to Figure 1.
5. Splice one electrical wire at 5 ohm resistor. Splice the other electrical wire at the remaining Circuit 909 wire, refer to Figure 1.
6. Reconnect in-car sensor connector.
7. Remove driver side hush panel.
8. Remove two fuse block retaining screws.
9. Move fuse block out of the way.
10. Route wires toward bulkhead connector.
11. Splice wires with the 2.2K ohm resistor under dash.
12. Remove bulkhead connector screw (5.6 mm or 7/32") from engine compartment side of bulkhead connector.
13. Disconnect right hand side of the bulkhead connector and pull away from bulkhead.
14. Clean excess grease from open cavities in the bulkhead connector.
15. Feed wires to engine compartment through open cavities in the bulkhead connector.
16. Route wiring underhood and secure along bulkhead.
17. Clean liquid line by condenser.
18. Solder connect Eldorado/Seville outside air thermistor to wires and wrap connection in electrical tape.
19. Attach thermistor to liquid line within 5 cm (2"), of the condenser using a plastic tie strap.
20. Cover with weather sealant.
21. Reinstall fuse block, driver side hush panel, and IP top cover.
22. Reconnect battery.
For warranty purposes use the most applicable Labour Operation at 2.1 hours.
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.
