2007 Chevy Express G1500 Van, Fuse #10, HVAC Fuse Blows

This 2007 Chevrolet Express G1500 van came in with the complaint that the A/C would not work. Neither the blower nor the compressor would come on. Looking at a wiring diagram revealed that fuse number 10 in the interior fuse box supplies power to both the compressor and blower control portions of the HVAC system.  The interior fuse box is located under the driver’s seat.


Fuse #10 listed as the HVAC fuse, 20 amp.


The position of fuse #10 in the fuse box legend.


Fuse #10 in the under seat fuse box.


It was blown. Now to figure out why?


Since the bulk of the HAVC system components are located under the hood on the passenger side I decided to take a look there first. I removed the coolant overflow tank that is secured with a 10 mm headed bolt.


Looking down at a harness that runs across a metal a/c line I could see that the split loom was broken and separated. I also could see the dark residue left over from the plastic rubbing on metal.


Placing a mirror under the wiring harness I could see that the wire insulation had be damaged.


It took some effort to rotate the harness around enough to see the damage without the mirror. I always try to visually confirm the location of a shorted wire before moving a harness around very much because many times the movement will cause very small insulation wounds to disappear. That in turn makes it difficult to guarantee the repair.


I removed some of the harness tape and split loom from the damaged area.


Separated the damaged wire.


Wrapped it and then the harness with electrical tape.


Installed new split loom with the split rotated away from the metal a/c line.


Drilled a hole in a flange on the blower case.


Then secured the harness with a wire tie to the blower case so that it could not come anywhere near the a/c line again.


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