Vehicle: 2017 Acura MDX, AWD, V6-3.5L (J35Y5), Automatic Transmission/Transaxle

Mileage: 98,320

Problem: The owner dropped her Acura MDX off at the shop because the air conditioning (A/C) stopped working. It was working perfectly one day and stopped the next day. Everything else seemed to work fine.

Case Details: The technician pulled the vehicle into the shop and observed that the A/C compressor clutch would not engage, and the A/C cooling fan did not operate.

The first thing he did was to verify A/C fuse #17 in the underhood fuse box was good. It was okay so he recovered the refrigerant to find it was slightly low. He recharged the system to the correct amount, but the clutch would still not engage.

Next, he removed the compressor clutch relay to test it and found it was good, so he checked for power and grounds at relay socket. There was 12volts and a good ground, but the relay didn’t click when it was inserted into the socket (with engine running and A/C commanded ON).

When he applied 12volts to the A/C compressor clutch relay socket, the clutch engaged, but no pressure split was seen on the gauges. He realized then that the A/C fan wasn’t running so he shut off the engine and checked the main fan fuse. The fuse looked good but there was no voltage at either side of the fuse connector. The problem had to be upstream.

After looking at a wiring diagram in ALLDATA he discovered there was a fuse that powered up the A/C main fan fuse. It was located on the positive battery cable. He checked that fuse, and it was blown.

Confirmed Repair: The technician replaced positive battery cable assembly, and the A/C worked like new. Fixed!