A single non-working accessory, light, or system on your GMC is very often traced back to a single blown fuse, and knowing how to properly find, check, and replace it saves an unnecessary trip to the shop for what's often a five-minute fix.
Jump to a section: Locating your fuse boxes · Finding the right fuse · Checking a fuse correctly · When a fuse keeps blowing · Quick reference table · FAQ
Locating Your Fuse Boxes
Most GMC vehicles have at least two fuse boxes: one inside the cabin (often behind a panel near the dash or in the glovebox) and one under the hood near the battery. Your owner's manual has a specific diagram for your exact model and year, which is the fastest way to find the correct box.
Battery tools
TOPDON BT200 12V Car Battery Tester Digital Automotive
$103.99Check the battery and charging system.
FOXWELL BC521 2-in-1 Battery Charger & Tester, Test Before
$162.35Check the battery and charging system.
FOXWELL BT705 Car Battery Tester 24V 12V, Alternator and Load
$159.89Check the battery and charging system.
Finding the Right Fuse
The fuse box cover typically has a diagram printed on the underside listing each fuse's number and the specific circuit it protects, letting you match your non-working accessory to its exact fuse rather than guessing. Confirming the correct fuse before pulling anything saves time and avoids disturbing unrelated circuits.
Checking a Fuse Correctly
A blown fuse shows a visibly broken or darkened metal strip inside the clear plastic housing, though a fuse tester or multimeter gives a more definitive answer than a visual check alone, since some breaks aren't obvious to the eye. Always replace a blown fuse with one of the exact same amperage rating printed on it — never a higher rating, which risks damage to the circuit it's meant to protect.
Fuse-block cable
ACDelco 4ST18 (88865133) 4-Gauge Positive Battery Fuse Block Cable
$15.84Battery-to-fuse-block cable. Confirm fitment by VIN before ordering.
When a Fuse Keeps Blowing
If a replacement fuse blows again shortly after installation, that points to an actual short or overload somewhere in that circuit rather than a simple worn-out fuse, and repeatedly replacing it without finding the underlying short risks further electrical damage or even a fire hazard. This situation calls for a proper wiring diagnosis rather than continued fuse replacement.
Wiring repair
ACDelco Wire Connectors, Replacement, 2 Pins
$90.99Connectors and loom for a shorted circuit. Confirm fitment by VIN before ordering.
Nomex Split Loom, 1 in. x 10 ft
$105.66Connectors and loom for a shorted circuit. Confirm fitment by VIN before ordering.
Quick Reference Table
| Step | What To Do |
|---|---|
| 1 | Identify the affected accessory or circuit |
| 2 | Locate the correct fuse box and matching fuse number |
| 3 | Pull the fuse and check/test it |
| 4 | Replace with the exact same amperage rating |
| 5 | If it blows again, diagnose the underlying short |
Frequently Asked Questions
Can I use a higher-rated fuse if I don't have the right one?
No — using a higher amperage fuse removes the protection that fuse is designed to provide, risking wiring damage or fire if a genuine short occurs; always use the exact rating specified.
Why did multiple things stop working at once?
Some fuses protect more than one accessory or system, so a single blown fuse can affect several seemingly unrelated functions simultaneously; checking your fuse diagram clarifies which fuse covers which combination.
Is it normal for fuses to blow occasionally with no clear cause?
An occasional blown fuse with no repeat pattern can happen from a momentary surge, but a fuse that blows repeatedly on replacement always indicates a real underlying fault worth diagnosing properly.
Do I need special tools to check a fuse?
A simple fuse puller (often built into the fuse box cover) and a visual check handle most cases, though a multimeter or dedicated fuse tester gives a more reliable result for fuses where the break isn't visually obvious.
Shop the Parts Mentioned
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ACDelco Professional Multi-Purpose Relay — useful reference and replacement hardware for the fuse box itself.
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95-Piece Mechanics Tool Set (Metric & SAE) — useful for fuse box panel and cover removal.
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ACDelco Gold Negative Battery Cable — addresses related power connection issues near the under-hood fuse box.