Got a new to me 1999 international 8100. I would really like to tackle the air conditioning, the M11 really heats up the cab. Don’t seem to be getting power to the clutch. I have power at the blue button. The only power I have going into the apads is the green wire that powers on and off with the blue button in on dash. The apads module doesn’t seem to be powering up, there are no lights and no power to wires on harness going out. Couldn’t seem to find any fuses related to ac system as well. Any help would be appreciated!
International 8100 air conditioning
Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by mission_creek, Jul 21, 2026.
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You should have ignition power at the red wire and ground at the black wire. Need to trace red wire and check for blown fuse.
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APADS fuses and relay is located on the inside cab wall directly to the left of the clutch pedal area. Key switch power will trigger the apads relay to send power to the red wire at the apads module, like mentioned. The APADs module will have at least the green LED light up once it is powered and the RED led will come on with any faults. You can test the clutch to the compressor by sending power out the dark blue wire. The power at the green wire you are getting is the "demand" signal, so that part is working.
mission_creek, JB7 and 062 Thank this. -
So I wound up splicing the green wire to the blue to bypass apds module. Not sure if this is right but the ac has been working for a week or so now.
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Just be very careful. The APAD module monitors the low and high pressure switches and also controls the engine fan. So with it bypassed there is technically no low/hi pressure protection or fan control. If you notice the engine fan never comes on when not moving, make sure you run the fan override or you will over pressurize the system due to no fan cooling across the condensor.
062 Thanks this. -
The relief valve did pop off once but hasn’t since. The fan on this truck is always on. Probably another can of worms but where should a guy start with that? You’re right though I need to fix the apads. Think it must be the module itself so I will order a new one and see if that works.
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