Here's the phone number and mailing address for commercial vehicles.

Phone number: 866-441-9638
Prompt 1. Literature
Prompt 2. Dealer Locator
Prompt 3. Customer Assistance
Prompt 4. Roadside Assistance

Address:
Isuzu Commercial Truck of America
Customer Assistance
46401 Commerce Center Dr.
Plymouth, MI 48170

If you need to get a wiring diagram or an owner's manual for an Isuzu truck, you can call Helm Inc. at 800-782-4356 or visit www.helminc.com and order a service manual.

Any Isuzu dealer can cut a extra key for you. They have the key codes.