Hard Wiring a Tom Tom ?

[Phil D]

I've just bought a new Tom Tom (One XL Europe) seems a nice piece of kit & on my limited use so far very accurate. My only criticism is that the battery life is quoted at only 2 hours or so & I don't want spaghetti all over the place - has anyone hard wired one in? I know there's a voltage issue and so far the best idea I've come up with is to have the cig lighter adaptor stored in the "ashtray" behind the flap, with the business end re-appearing at the top of the dash - is there a neater option ? Any ideas / experiences would be very welcome. Thanks
Phil

 

[John Turner]

Dear Phil,
I hard wired my Tom Tom in a W124 to avoid having the ash tray always open when it was connected! I hard wired the device into the back of the cigar lighter. The cable then came out where the transmission tunnel carpet/plastic edge meets the dash board, and I squeezed the wire between the wood console and facia up to the central air vent, where I clip the Tom Tom using an adaptor/bracket This is much more secure than those daft windscreen suckers, and the clip can be pulled of the air vent leaving no sign. This way, only about 5cm of wire shows. I have another W124, and in that one I hard wired a 3 port terminal in the same way, locating this under the right hand side of the dash board where it cannot be seen, just below the main light switch. The wire ran along the lower edge of the dash below the steering column where there were already some clips (between lower dash cushion panel and an underdash panel) which hold it neatly in place. This allowed the Tom Tom and other devices to simply plug in and be located in the right hand corner of the dash or on the right hand air vent.
I started by snipping off the lighter type socket supplied on the cable (in the first case of the Tom Tom cable, and in the second case, of the extension port adaptor) as closely as possible. The cable end was then pushed into the dashboard where the central tunnel carpet meets the lower panel of the dashboard to left under steering wheel. There is a hole under the carpet here, leading in behind the radio area (and used by other cables eg antenna).
With negative battery terminal disconnected, the cigarette light socket inner workings were revealed by removing gear surround wood trim. This was done by accessing screw under carpet of central tray (mine is a W124), pulling trim carefully up from window switch sockets, together with gear gaiter and mirror switch attached). The ash tray can be opened, and tray removed. Two screws in back were undone allowing whole unit to come away and to be unplugged. By feeling inside behind central dash area and below radio, I located the cable ends on the right, and fitted an 8Amp chocolate box connector to both the positive (red) and negative wires (black) of the cable (colours as on my model).
I then prepared a 30 cm piece of (red) 1mm diameter wire (as per cigarette lighter wires) with an 8 amp in line snap across type connector one end. I prepared a second similar piece of wire (black) with an in line fuse (2amp as supplied in original cable socket) and connected these to the chocolate block connector from the cable . I then simply tapped into the positive and earth cables to the cigarette lighter (positive was black and yellow, earth was black and violet in my car) using the in line snap fit connectors, and insulated these with tape just to be sure. (I hate these connectors, but done carefully they are successful and cause least disturbance. I have had no problems with bulb detector. ). I reconnected the battery and tested everything prior to re-assembly.
It is obviously important to ensure wires up to fuse and earth are same as cigarette lighter ones (diameter, amps etc) and that everything is well insulated and positive and negative wires are properly connected and fuse is in place for protection to avoid a behind the dash fire! The above worked for my car, but if you intend to do something similar, do check everything because I cannot guarantee that this will work the same in yours. The above might just give you ideas. The job must be done with great care to ensure electrical safety - if in doubt I suggest contacting an auto electrician. Correct fusing is essential.

 

[Phil D]

wow John ! - many thanks for such a detailed reply - way beyond my electrical capabilities but I can pass it in to someone who knows what they're doing - in any event I'm sure that many other people out there could benefit from your reply.
In between times I think that Brodit (who have had some favourable mentions here) do an off the shelf solution fo around 50 or 60 quid which I'm also going to expore
either way it sounds like a problem just about solved - many thanks again
Phil