Well it says it will if you use the "Does this fit my vehicle link" but I don't know how much you can really trust it. When I tried to hook up my cargo box with the wiring/converter that Tone provided, I had a similar problem to etlsport above, only that I got running lights, turn signals, but no brake lights. Took it to a trailer shop and they said that Isuzu's actually used a European style wiring system, so the converter need to be a 5-way instead of a 4-way (I think). Note that's the converter, not the plug - there are always four wires in the plug.
Don't know if that helps much.
The only reason we need a converter is because of the independent turn signal bulbs. And that is what that is for so it will work if hooked up correctly. shawn