660 nuvi charges fine with AC charger, but not with 12v car charg

Make sure the fuse to your DC socket isn't blown. Check the fuse in the tip of the charger. When your Nuvi 660 is plugged into the cradle, you should see a yellow lightning bolt over the battery icon. If you don't see this, then your Nuvi isnt getting voltage from the car charger.

You can also have a bad cradle or charger plug that plugs into the cradle. More info can be found here:

http://www.sharc.net/gps_charger_repair.htm

- Jim

That simply shows that the power adapter/cord is bad. To confirm it, all you need to do is to borrow another charger then plug your garmin nuvi on it to see if it charges, if it charges, then it means what you have to replace is your charger. The former battery is not bad since it can power on and off the gps.
Solution, Get a new charger for your garmin nuvi 660 gps receiver. Am very well convinced that,replacing the charger will do the job.
Hope this piece of information helped.

You probable have a blown fuse in the cigarette lighter adapter.... Unscrew the silver tip of plug and check fuse..... be careful its spring loaded..

Yes, many aftermarket chargers are not wired the same as a Garmin charger and will cause your Nuvi to think it's connected to a PC. What happened to the original charger that plugged into the cradle (the part your Nuvi snaps into?)

Please see this link:

http://www.sharc.net/gps_charger_repair.htm

- Jim

Your not the Lone Ranger on this problem. After awhile the battery will no longer take a charge. IT is not a replaceable battery by the user. It must be sent back to Garmin for a new battery. If you only use the gps when in a vehicle, it still will work fine when pluged into a 12v source.

Which charger are you using? The USB? AC charger? Car charger? It should work fine when using the AC or car charger. Using the USB places it in USB mode for programming.

Are you using the charger that came with the unit? If you do not use the one that came with it, the unit may be reading this as though it were plugged into the computer. It will charge then, but will not operate unless unplugged - just as you are describing.

Needed to change the fuse

okay if it charges with your DC, and it gives you plomebs with the AC, i would only charge in the car because your AC charger must not be changing the current to volts and you can easily blow it up... you can buy another charger and that should solve your problem

Well , maybe yes ,maybe not.
I will recommend this for your NUVI 660:

http://www.gpsmart.ca/item733.htm

$25.00 CDN