2004 Hummer H2 Owner's Manual - Page 312
2004 Hummer H2 Manual
Page 312 highlights
Instrument Panel Jumper Wiring Harness Notice: If your vehicle has factory or dealer-installed HUMMER off-road lamps, the place where an electric trailer brake connection must be made is already in use. Do not attempt to double-up or "piggyback" the connection, because this could cause a failure or damage to your vehicle, the electric trailer brake system, or both. If you want to connect a trailer with electric brakes to your vehicle, see your dealer to disconnect the off-road lamps. Also, read Add-On Electrical Equipment on page 5-101 for more information. This harness may be included with your vehicle as part of the heavy-duty trailer wiring package. {CAUTION: Be sure to use only the correct trailer brake harness, the one intended for use on your vehicle. If you use some other trailer brake harness, even if it seems to fit, your trailer brakes may not work at all. You could have a crash in which you or others could be injured. Use only the trailer brake harness intended for your vehicle. If it is no longer available to you, be sure to get a proper replacement from your dealer. This harness is for an electric brake controller and includes a trailer battery feed fuse. It should be installed by your dealer or a qualified service center. 4-86