2820 speaker (extra plug on cig adapter)

Not Sure but it might be for Blue Tooth

Those extra connections on the plug (just like the the 2720) is for the DR cable for the 7200 & 7500. One wire is to connect to the backup light to let the unit know it's going in reverse, the other connects to the speedometer output to dead-recon when the unit can't get a satellite fix.

Look at page 53 of the manual located here:

http://www8.garmin.com/manuals/960_OwnersManualforUS.pdf

Joe

No, I don't think that extra outlet/plug on the Cig.Plug adapter has anything to do with Dead Reckoning because the 2730/2820 does not have the dead reckoning feature or capability.

I don't know what it is.... but I'm am pretty sure I know what it isn't.

Tim

it's dead reckoning, the chord is just generic and the main speaker piece is used for multiple GPS units- and i'm pretty sure I know that as a fact

Isaacjd,

Thanks for the info.....

Now that I know that, I went and looked around and found that there were two older, and now discontinued models, of the streetpilot which also had dead reckoning. The 2650 and the 2660 both had it. They must have continued using the same old ( and problematic ) power/speaker cable.

My error, I only thought the 7500 had it.. I know the only difference between the 7200 and the 7500 units is the dead reckoning, and it sure costs a pretty penny more to have it on the unit.

Regards, Tim