Where is ac control module located - 1991 Chevrolet Silverado 2500

FSCM - is a fuse, a 25 amp fuse located in the underhood fuse box which supply's battery voltage to the fuel pump flow control module .This is shown in service repair manual
If replacing the fuel pump flow control module, program the control module. Refer to Control Module References.
But in Control Module References it's not listed as a module needing programming . Think this module is plug an play .

25 amp PWR OUTLET fuse , location - under hood fuse box. This fuse supply's power to the Accessory AC/DC power control module .
MSM 10amp fuse location instrument panel fuse box . This power's the object alarm module .

Powertrain Control Module (PCM)--Right Rear Of Engine Compartment--Near AC Receiver Dryer.
Body Control Module (BCM) Behind Lower Left Of Dash.

Attached are the diagrams requested - good luck!
Fascia 1


Fuse, (Amps), Circuit
F1 -
F2 -
F3 -
F4 -
F5 -
F6 -
F7 -
F8 -
F9 (5A) Supplementary restraint system (SRS) control module
F10 (10A) Four wheel drive control module
F11 (5A) Parking aid control module, self-parking system control module
F12 (10A) Gas discharge headlamp control module (LH)
F13 (5A)
ABS/ESP system, AC system, anti-dazzle interior mirror, heated windscreen washer jets, seat occupation control
module, transmission control module (TCM), reversing lamps, engine management system
F14 (10A)
ABS control module, engine control module (ECM), heated seats, power steering control module, suspension
control module, trailer control module, AC control module, instrumentation control module, CAN data bus
gateway control module
F15 (10A)
Auxiliary heater, data link connector (DLC), parking brake control module, engine management, headlamp
direction control module
F16 (10A) Gas discharge headlamp control module (RH)
F17 (5A) Instrument panel
F18 (10A) Mobile telephone control module, multimedia control module
F19 (10A) Steering column function control module 2
F20 (5A) ABS control module, AC system, transmission control module (TCM)
F21 (15A) Door function control module, left rear, door function control module, right rear, multifunction control module 2
F22 (5A) Alarm system, multifunction control module 2
F23 (10A) ABS/ESP system, AC system, data link connector (DLC), rear view camera control module, headlamp switch
F24 (10A) Door function control module, driver, door function control module, passenger
F25 (20A) Transmission control module (TCM)
F26 -
F27 -
F28 (40A) AC control module, auxiliary heater
F29 (15A) Rear screen wiper motor
F30 -
F31 (20A) Auxiliary power sockets, cigarette lighter
F32 -
F33 -
F34 -
F35 -
F36 -
F37 -
F38 (10A) Steering column function control module 1
F39 (20A) Headlamp washers
F40 (15A) Trailer control module
F41 (15A) Trailer control module
F42 (20A) Trailer control module
F43 (25A) Sunroof control module
F44 (25A) Parking brake control module
F45 (25A) Heater blower motor, heated rear window
F46 (30A) Door function control module, driver, door function control module, passenger
F47 (30A) Door function control module, driver, door function control module, right rear
F48 (15A) Fuel pump (FP)
F49 (20A) multifunction control module 2
F50 (25A) Parking brake control module
F51 (40A) AC/heater blower motor control module
F52 (30A) Seat heater control module
F53
(20A/30A)
Headlamp washers
F54 (30A) Auxiliary power sockets
F55 (15A) Lumbar support adjustment
F56 (15A) Suspension control module
F57 (25A) Sun blind control module
F58 (1A) Trailer warning lamp
F59 (20A) Multimedia control module
F60 -

Fascia 3




in engine bay



Fuse (Amps) Circuit
F1 -
F2 -
F3 (5A) Multifunction control module 2
F4 (30A) ABS/ESP system
F5 -
F6 (5A) Instrumentation control module, steering column function control module 2
F7 (40A) Ignition main circuits
F8 (25A) In-car entertainment (ICE)
F8 (25A) Voltage converter
F9 (5A) Mobile telephone control module
F10 (5A/10A) Engine control module (ECM)
F11 (20A) Auxiliary heater control module
F12 (5A) CAN data bus gateway control module
F13 (15A/30A) Engine control module (ECM)
F14 (5A) Engine management system
F15 (5A/10A/15A) Fuel pump (FP), AC compressor clutch, engine management system
F16 (30A) Multifunction control module 2
F17 (15A) Alarm system horn
F18 (30A) Audio system
F19 (30A) Windscreen wiper motor
F20 (10A) Engine management system
F21 (10A/20A) Engine management system, fuel pump (FP) control module
F22 (5A) Clutch pedal position (CPP) switch
F23 (10A) Engine management system
F24 (10A) Engine coolant blower motor control module, engine management system, engine coolant heater
F25 (40A) ABS/ESP system
F26 (30A) Multifunction control module 2
F27 -
F28 (50A) Glow plug control module
F29 (50A) Electric seats
F30 (50A) Ignition switch circuits
Location Component
1 Petrol: Engine control (EC) relay 1
1 Diesel: Ignition main circuits relay
2 Petrol: Engine control (EC) relay 2
2 Diesel: Engine control (EC) relay

the module is actually the head unit in the center of the dash there is a electronic speed control module that will be located on top the interior heater box behind the glove box unless you are lucky enough too have one that was actually assembled in the states those units that where are located under the hood on the outside blower box passenger side of car close to the valve cover side of the box

The Constant Control Relay Module is located right underneath the air cleaner box. Please be sure to replace it with the correct module, they are not the same. Use all the numbers on the old one, like F8CZ-12B577-AA, AB, AC, there are others.

It's not the relays. It's the control module or wiring. If you bought a used one, it could be bad. If new, it could be bad also, it has set on a shelf for years. You need a schematic. Your scanner already said this. A/C not requested..

there is a module that controls the motor located arend the blower moter that will need to be replaced. Not sure if this is available other than dealer. check with auto parts stores first. I would ask for blower motor control module.If this helps please reply and good luck

You replaced the blower control module or the blower control panel on the dash? This has automatic temp control right?

I have a 1989 Olds 98 Reg. Bro. I have recently located my ac control module under the hood on the firewall. removing it should take about 20 mins depending on whats in the way. but to cost to replace is the kicker. I found the part @ NAPA for $240.00. may i suggest craigslist.org and look under parts for your car or one like it. the car made like mine would be a 1989 Cadillac DeVille. I hope this helps.