Shorted IACV= No start

CF9 Honda Accord with a 2.3L engine. While testing an alt I had replaced on the engine earlier I revved the engine and heard fuse/s pop, the engine then died. I noticed there was no CEL in the dash and I was now facing a cranking no start. Pondering if to solve this latest development or to hit up a bar @ 9 a.m, I decided to grab a test light and search for the fuse/s i heard pop in the engine bay fuse box.

In the fuse box I discovered that 15A "H", according to diagram, did it's job. This fuse feeds the switch side of the main relay and is hot all the time. It feeds the PCM, injectors, and IACV through a WHT/GRN (relay feed) to YEL/BLK wire (load feed). I unplugged all loads in the circuit and "placed" my test light, to 12v, on the load side of fuse with the KOEO, closing the relay switches. The test light did not light so short was not present, yet. I then began plugging in components starting with the IACV and the light came on.

Leaving the IACV unplugged I plugged everything back in and replaced the fuse. The car started and ran till I obviously plugged the IACV back in and the fuse immediately popped.

Right on ! Cool

For anybody wanting more on IACV diagnostics Paul has a good video on his free channel.

Great work, thanks for sharing your diagnostic process with us!