Scratch that.... If you've already cut off the plug its kinda hard to back out . You'd be better off checking the voltage at the end that connects to the garmin. It looks like from other posts there is a step down and like the one guy suggested you can buy "cigarette" adaptors and wire one in behind the dash, and plug the GPS cord into it permanently.

 

Though, after the "snip snip" one finds more than just two wires, things could get very interesting. Plus, at that point, returning it back the store becomes more difficult.

 

Good to know I won't have to "snip snip" and will just have to look for a 12V adaptor to take the Garmin adaptor behind the dash

hmm.. the above sentence sounds funny

 

You can usually tell if there are more than two wires by looking at the plug and the wire itself. You can't tell if the voltage would be different simply by looking though.

As for the 12V outlet, you can get them at any autoparts store and at radioshack.

 

TimK, it seems like the 12V outlet featured in your photo has 2 wire taps (I assume one is positive and one is negative, plus ground loop).

I plan on using one of those "Add-a-circuit" mini-fuse at one of the fuse blocks under the center console to power this extra 12V outlet. My question is, do I connect both black and red wire of the 12V outlet to the same "Add-a-circuit" wire? Does the positive and negative in this case make a difference?

 

No, that's just the way the picture looks...there are only two wires. The red slip-on connector attaches to a tab on the back of the outlet for HOT. Then in the picture the Red wire loops around and has the inline fuse holder you see but the end of the Red wire is not shown. This end would be connected to the fuse tap or to the battery depending on your install. The Black slip-on connector attaches to another tab on the back of the outlet for Ground. Then the black wire is connected to any grounded metal in the vehicle. Its not like an outlet in your house with +, -, and ground.

 

gotcha, thanks Tim for the clarification!!!

 

I forgot to mention....I installed this exact outlet as a spare in our last car. The black plastic trapezoid is only an option part. The outlet itself is small and round and has a slightly larger lip so that it can sit flush in a cutout. I cut out a little round hole using a dremel and slid the outlet in place. There are two plastic tabs on the side that help snap it in place. It also has a nice rubber cover that is attached. Obviously for your needs behind the dash it probably won't matter.

http://www.radioshack.com/sm-12vdc-c...i-2062272.html
$7.49 at Radioshack Catalog #: 270-1556

 

Well, I took my MMH on its first long trip this past Thanksgiving, holiday, long weekend. A trip long enough that it would involve more than one CD (ie, a journey that crossed CD boundaries).

From my previous experience, and my reading here, I decided to insert the CD for my destination into the NAV unit, before having it subsequently calculate a route for me. That seemed to work out just fine. It didn't seem to mind or care that I did not have my current, origination, CD in the unit. Besides, I knew how to get onto the highway from my house. It was only the side street details upon my arrival at my destination that would be eventually needed.

Everything started out well. Since I quickly got onto the interstate highway, the destination CD had that major road in its database. It did a very good job tell me where to go, and even (to my pleasant surprised) told me to stay on the current highway at points where there was a major interchange. My Garmin rarely, if ever, gives me verbal directions telling when not to turn.

The problems started happening when I eventually pulled off the highway into a rest area (nature called for me and my kid). I turned my MMH 'off'. Upon returning to my MMH, and starting it back up, the NAV system asked me if I wanted to continue or cancel. I chose continue.

Now, just to let you know, at this point, I was well into the area covered by the destination CD that has been inserted into the NAV system since I left the house.

The NAV system immediately complained. It wanted the CD from my origination place. So, OK, I changed the CD. I figured that, maybe, it needed to re-sync itself from the very beginning of the journey, and once it did that, ask me to re-insert the destination CD.

I waited for a few moments, and after it seemed to have finished reading the origination CD, I eject it and put the destination CD back in (without any prompt from the NAV system).

No good. It immediately told me that the CD just got corrupted.

I put the origination CD back in, and then continued my journey.

I figured that eventually, the NAV system would ask for me to insert the Destination CD; the CD that covered my current location.

Nope. Never happen.

When I finally got close to my final destination, I was prompted to exit the highway. That was correct. However, once I exited the highway, since the NAV system still had the wrong CD, the NAV system was completely lost. The map showed no roads, at all, upon exiting the highway. With no roads, the NAV system had no clue as to where I was suppose to go!

I tried again to force a change, and ejected the origination CD, and replace it with the right destination CD. Nope. Got the corrupted CD message again (BTW, apparently, the NAV system doesn't re-read the CD's file directory when a new disk is unexpectedly inserted. The Nav system then, misinterprets the mismatch between the old file directory and the new files, as corruption).

At this point the NAV system was totally useless and basically brain dead.

I finally made it to my destination without the NAV system's further help.

Later on, when I got back into my MMH, the NAV system once again asked me if I wanted to continue or cancel. I guess it was clueless that I was already at my destination. This time, I chose "cancel". I then ejected the origination CD, inserted the destination CD, and pressed "MAP".

That worked! It finally showed me a map of my current location.

In hindsight, I guess at the rest stop, I should have picked "cancel" too, and had the NAV system completely recalculate a new route, from the rest area to my final destination. However, I really should not have had to do that. Right? "Continue" should have worked too!

Needless to say, I am quite disappointed with this unit. It seems that it can't, correctly, handle journeys that cross CD's. What a waste.

 

Well, thanks for the heads up there Walt.

I'll remember to "cancel" after I cycle the power, and reinput the desitination so to let it recalc the route from current location, instead of relying on any memory the system has (apparently, NONE!)