This is for a 2004 H2. I don't know if it's different from any other year H2:
Remove negative (black) cable from battery. To prevent accident while I'm working in that tight spot, I covered the cable with a latex glove..
The computer is under the hood, next to the battery, under a BIG black plastic shroud cover. Pop the cover off (2 tabs, one obvious on top, the other bottom left towards radiator), you'll see 2 wiring harness. Use 9/32 skinny socket (I used the type that attaches to a screwdriver) to remove the harness that's closer to alternator/passanger side. Once it came off, verify that the plastic plug is BLUE in color.
Install the Jet chip (only goes one way, with the "claw" facing alternator/passanger side), using 5/16 skinny socket to tighten. Then piggy-back the factory harness on to the back of the Jet chip, and tighten with 9/32 socket.
Re-attach negative battery cable, start your H2 to verify no error.
A few notes: 1) I had to snip off the zip-tie that holds the bottom factory wiring harness, before I can piggy back it onto the Jet chip. 2) I cut the plastic shroud cover using a tin-snip. Easy, but you'd need a BIG cut (not itty bitty trimming), before it'd fit over the Jet. 3) Install was not difficult, but time consuming as you don't have much room, and access deep down the engine compartment was very awkward. Too I had to hunt for my cordless drill socket attachments.
But the result is DEFINITELY NOTICABLE. I'd go so far as saying every (2004) H2 NEEDS this very gratifying mod!
HIGHLY RECOMMENDED!
