12/24 volt adapter/external speaker no longer works

That's called a fuse - and if it's bad, yes, it can be replaced.

That is a fuse. Check it visually (sometimes the fuse wire are so small they are very hard to see) and with an OHM meter. Most likely cause of sudden failure.

My wife's Nuvi worked for about 6 months and then would drain the battery when operated in the car cradle. I checked for voltage coming out of the cable when it was plugged in and got nothing. Turns out the wires inside the cable broke due to who knows what - flexing cable during cold, over-flexing of cable in general, poor manufacturing??? Anyway, it was still in warranty and one call to Garmin got a new cable shipped with no questions asked. The new cable fixed the problem. Is your unit still under warranty? Even if it's recently expired, it may be worth a call - Garmin is usually very interested in keeping their customers happy, especially if you are pleasant with the representative on the phone.

If it is a blown fuse you need to replace it with the same value fuse. More than likely a sales person at your local Radio Shack or auto parts store should be able to help you if you are not sure.

The wire in the fuse was broken, so I went to my local Radio Shack yesterday and purchased a replacement. It now works like new!

The cost of the fuse was only $1.99, plus tax. Compare that to the cost of replacing the entire power outlet, which would've run about $35-45. What's even better - there are four fuses in the package, so now I have three spares.

Thanks for the advice, everybody!

-Dave

Glad to help out - It's always good when something works out the way you want it to