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How to Troubleshoot the Electrical System in a GMC Sierra

by Contributor

Recommended by "Consumer Reports" as a pickup truck, the GMC Sierra, is a reliable truck and sibling to the Chevrolet Silverado. It comes in two versions, the regular 1500 and the heavy duty 2500. Both come with a decent electrical system that needs only occasional diagnosis and repair.

Step 1

Ask GM whether you need to take your 2007 to 2008 Sierra back to General Motors for a quick fix to the heated windshield wiper fluid system. General Motors recalled 857,735 vehicles for a possible short circuit risk from this component that can cause other electrical failure and even a dangerous situation. The fix is a wire harness with an in-line fuse.

Step 2

Suspect a defective anti-theft system if your GMC Sierra's lights are flashing away while off. It can lead to further problems with wire insulation or harness bundles.

Step 3

Look further into the problem of losing power while driving with or without the check engine light coming on. It may be something a simple as the fuse to the OBD2 connection that needs replacing.

Step 4

Check the switch for your windshield wipers if they won't turn off. It could be a bad switch that needs replacing. Problems that require the replacement of the wiper motor are usually signaled by wipers that don't function at all.

Step 5

Watch out for modifications when you buy a used Sierra pickup. Check all the electrical components, including lights, stereo and turn signals. Sometimes wires get crossed; if not, look at the connectors.

Update the electrical system in older GMC trucks. The older trucks are experiencing a resurgence in popularity as owners restore them. Don't overlook the electrical system, which needs a makeover in order to be able to handle today's power needs.

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