Car Stereos: Yellow Wire, power fuse, blown fuse

Question
Hey Brian, I found you via a post you had made about a guy with an 86 Ford Laser with grounding problems.  I have similar issues, only my problem is the Yellow Wire.  I have a 2001 GMC Sierra, and using a multi-meter found that my red wire has 12.4 volts, but Yellow has nothing even with the key in any position.  Any ideas on where I need to look for the fuse that may be blown, or is it a bigger problem?  Please say fuse!  
Thanks for your time,
Dustin

Answer
Hi Dustin,

I think a blown fuse is the most likely explanation.  The constant power fuse for your truck's radio should be located in the engine compartment fuse box; it's 15-amp and will be labeled "radio" in the chart on the fuse box lid.

Even if the fuse isn't the issue, you still have a few options for working around the problem.  You can extend the yellow power wire down to the cigarette lighter wiring, just below the climate controls; or even down to the red ignition power wire under the steering column.  (If you connect to the ignition switch wire, you'll want to put your own fuse on the new wire near the tap point).

I'd be surprised, though, if replacing the fuse doesn't solve the problem.

Hope this helps!

Brian