How to use GPS antenna in rear view mirror as an external antenna for aftermarket GPS systems

[ianx, manchester]

fgwinn - 10/14/2004 9:24 PM

Is it feasible to use the GPS antenna in the rear view mirror as an external antenna for an aftermarket GPS system?

Well yes it may be!

Here's what i know about US SLKs. They use the same GPS antenna for both the SatNav and the Teleaid.
They do this via a Splitter located on the module bridge in the trunk. (Pic attached)

All you would have to do is check if this splitter exists in vehicles without either COMAND or Teleaid.
If not, if some kind soul can get a Part Number and price from their dealer that would be a help!

I'm not sure if European vehicles have this splitter at all, as we don't use Teleaid, but if we can get hold of this splitter then we can certainly use the in built GPS antenna if it exists on non-COMAND vehicles.

BTW I checked on prices of commercial GPS antenna spltters. They are NOT cheap, costing several hundred pounds each, although maplin do a cheap one for around 20 pounds.

[bsharp]

Given many of cars are built with componants existing even if they are not used by an ordered accessory e.g. rain sensor, gsm aerial (in my audi).

Do SLK's with no teleaid or command fitted still have a GPS aerial - if so where does the cable terminate??

I use a Road Angel (the new one) GPS camera alert, and I would like to find a location away from the wind screen for it, thus requiring an alternative aerial.

I am also planning to a fit a trakm8.com again requirng a GPS aerial - this will also out put NMEA data for my pocket PC with tomtom.

[chris-h]

Bsharp
Have you hard wired your Road Angel into the car. My Merc dealer is suggesting that I shouldn't break into a cable at the fuseboard on the left hand side of the dashboard (like I did on my previous Audi TT)but should get an electrician to wire it straight to the battery.
If you have how did you do it?

[bsharp]

Not yet - I am waiting to get hold of the car first!

With my previous cars I have taken power from the back of the stereo or 12v socket bring the cable out around the foot well below the glove box, or above/below the stearing column for powering the ipaq.

Of course I can't qualify any of this in the SLK as I have yet to take delivery. I wouldn't consider taking it from the battery as this would require getting the cable through the bulk head, and nor will it turn off with the ignition where as the 12v socket hopefully will.

For the trakm8 i am unsure where I will take power from, as it need to be continuous, I guess I will see where they cable the tracker to, and use the same power source.

[fgwinn]

The 12v accessory socket is definitely wired through the ignition switch.

bsharp - 1/19/2005 10:18 AM

....and nor will it turn off with the ignition where as the 12v socket hopefully will.

[joyfulheart]

Chris H...have you got pics of the road angle in your car? I am getting this and planning on using the 12v socket, but also expecting it to be ugly which is a pity, so wondering how to find the best set up. I dont want to be removing the dashboard, my RX7 creaked for the rest of its life after this was done. I would like to keep the set up simple.

[chris-h]

Currently I've just used the mounting bracket for the RoadAngel 2 which has suckers which stick to the the windscreen. I rests on the top of the dashboard and sticks to the base of the windscreen directly infront of the passenger. Its currently plugged into the 12v socket under the glove box. The mounting bracket is reasonably neat and does damp out any vibration. I actually prefer it on the passenger side of the car because the little blue screen is quite bright if it's directly in your line of vision at night. The alarm on it is pretty loud so not much chance of missing it.
The big issue is the power cable. I'm using the curly cable stretched over the dashbord into the 12v socket under the glove box temporarily, which looks pretty naff - hence the desire to wire it in permanently. It would be OK if I could get the wire to the back of the 12v socket inside the dashboard but I'm a bit nervous about taking the underneath of the dash to pieces. Sorry don't have a photo of it -but will try to organise.
Road Angel 2 is worth its weight in gold though - it's much better than my old Geodysis and has stopped me being flashed by cameras at least twice a week!

[joyfulheart]

Its a shame they are not rechargeable, then we could forget about permanent cables, and also move it between cars. MB sell the road angel, I wonder if they run the cables discretely when they install it.
I will ask the MB service team.

[bstronger]

I am not sure what is meant by 'external' but I can tell you that my Garmin Quest GPS works faultlessly situated on my fully extended steering column.
I continue to be amused at the discussion of 'ugly external', poor display, etc etc. The elegant solution is very simple - and the data base is superior to MB, at least in the USA. -Robert

[ianx, manchester]

ianx, manchester - 12/11/2004 7:39 AM

Well yes it may be!

Here's what i know about US SLKs. They use the same GPS antenna for both the SatNav and the Teleaid.
They do this via a Splitter located on the module bridge in the trunk.

Just so we have it recorded for posterity, the part number for the GPS splitter is A210 820 24 89
I'll post the hi-res picture later.