bought a cheap tomtom for my w124/w123 and for times when i rent a car..... and am looking into hardwiring it in my w124 so i dont have to plug it into the cig lighter when the internal battery dies...

my dad hard wired my radar detector years ago into my w123 via the glove box light bulb... but as most of you know... 94-95's dont have glove boxes.

so... for the guys that have electronics hardwired...

where did you tap into?
what wires (fuse holder?) did you use?

any help would be great
-thanks
carino

 

should be a a fairly easy splice or hardwire. I did one on my dirtbike and just hardwired directly to the battery with an inline fuse. you can run it to a switch if ya want. I just unplug mine and there is no power drain...plug it in and you don't need the ignitions on if your hardwired or spliced to a constant 12v

 

That's a wonderful idea...never thought of that...HATE using the charger all the time and since you (charles) read the issue I am having with my cigarette lighter, this may be the option!

 

I had a hardwire done for my V1 in the W124 coupe. Tapped the dome light.

 

I hardwired a cradle for my PPC to use as a gps....I hooked it up through the cig lighter...cords are a pain to use and look bad....so hardwiring is always worth the time I think

 

You should have an empty fuse terminal in the fuse box, use that and it will look slick too.

 

I'm going to invest in a Valentine1 very soon and wire it to my domelights so its consealed.

Got my second speeding ticket within three weeks today on my way to work.

 

I hard wired my Radar Detector in as well, like 2phast did on his 500e :

http://www.2phast.com/500e/default.htm

I just used my volt meter, unclipped the two wire harnesses for the dome light and found which had 12v with the ignition on, then used the ground connector that is screwed into the body just behind the dome light when u take it out.

I also plan on installing my GPS system soon , the same way - I just haven't got around to it yet and now i am dealing with tranny problems. The reason I keep the cig-adapter free from 'goodies' is because I plug my ipod monster cable into it for the time being. Soon I'll get that put into a cradle though, and hard wired into the Apline head unit.

 

you can always find a 12v source and ground anywhere easily or hook it up to the fuse box. I hate cluttering up the cig light. I need it at times for my car charger. I was thinking of hardwiring my IGO car charger but too much of a pain. If I hardwire it, I can't find a place to dock my phone.

 

This is where I found my key on / 12v source :



The black / red striped wire is hot with 12v with the key in 'on' position, here is a pic of the ground connection just beyond the dome light where the wires come up into the roof:

 

Hmmm....very nice idea...do you have anymore pics or a write up? Could you do one for those of us less DIY inclined who would like to hardwire?

Thanks in advance!!

 

DAMN son. slow the f\/ck down.

 

I just took some pics today of mine in hopes that it would help, sorry no write up - I'll do one if you guys want me to, but if u can take out your dome light and you know what wire to tap into you can do this easily with a wire nut ; then use the ground screw that's already there for your ground connection. So you only cut 1 wire it's pretty easy.

There has to be an easier method than this because this was the easiest setup for a radar detector, which was pretty easy to wire from that point - after you pop your rear view mirror out. It all depends on where you are putting the GPS - as a power source such as behind cig. lighter might be a better location, but I guess you could just route your 12v wire under the headliner, and down the pillar like this if you are going to be installing it on your dashboard :

 

id like a write up with pictures....

i have no clue myself as in what kind of wires to get.

would i have to get a fuse holder?

and if so... what size fuse do i put in it?

for me... i guess i would tap into the dome light the run the wires behind the headliner and down the driver side pilliar to mount right above the driver side speaker.

basically my plans are to cut the cig lighter end of my power supply.... and (a) either use those wires (if possible) and tap them directly into the dome light..... or (b) wire those to a fuse holder then run wires from the fuse holder to the dome light.

you guys with electical knowledge... would either of these ideas work?

any input would be appreciated

-thanks
carino

 

I second that idea for a write up if you will, please Mr. Capthook, sir!!

 

What do u guys need pics of when i do mine? i'll do a (real) write up with pics once i get around to installing mine. I have to fix this transmission first though.. one MBZ thing at a time. However, here is exactly how I will end up doing this job when I finally get around to doing it:


[ FIRST RULE OF THUMB : WHAT VOLTAGE IS YOUR GPS UNIT - CHECK THE ADAPTER - 12v or 5v? IF 5V, DO NOT WIRE DIRECT! ]

1. pull the dome light down

2. on the pass. side dome light harness, locate the black / red striped wire

3. cut the wire back at the harness 3-4 inches or more; strip the wires and reconnect them into a 'I' to prep for a wire nut, and your gps' power wire

4. locate your ground connection (a philips head) , just above where your wires to the dome light come up into the roof.

5. Strip the wires on your GPS's harness - it (could) be four wires or two:

Red - connect to 12volt Power w/ 2a inline fuse
Black - Connect to Ground
White - data in.
Brown - data out.


6. Route the GPS unit harness up in through the drivers side pillar, into the roof / dome light area if extra wire isn't necessary. If so, only small gauge wire is necessary for a GPS unit. Test the connection with your GPS unit in the car to make sure the length of the wire / look is going to be right

7. Use a 2A fuse with in line fuse holder if you want to fuse the power connection to your GPS unit (I would) ; then connect the black / red striped wires to your gps' in line fuse holder / 12v power cord.



8. Connect your ground wire using a wire washer to the philips head ground connector above the dome light.

9. Test the GPS system with Key ON

10. Reinstall your trim & Domelight


P.S. - what TomTom unit are you installing, be careful, as I am pretty sure some have a built in 5v fuse in the plug and you cannot cut off the plug & feed them 12v. You might need to use a voltage regulator. Read the output on your GPS' adapter, FIRST. Mine is 12v 1A ; so I can plug right into the car's 12v power source. Yours might be 5v, so you'll need to voltage reg it

 

I have the Garmin Nuvi 350...built in antenna.

 

ZorroAMG ; the Nuvi 350 uses a mini usb cable for power - i'm not aware of any hardwire kits for it yet but I know it can be done:

The Nuvi's original cigarette lighter adapter says its output is @ 5 Volts / 1 Amp. At Fry's, u can find a cigarette lighter adapter with a female USB port. It also outputs 5V, 1A & has your fuse built in

Look here:

http://www.simonbee.com/index.php?op...id=17&Itemid=9

...as for the tomtom, I think it's 5v / 2a if i remember correctly... you could just cut off the Cigar plug / Power Adapter that comes with your TomTom and expose those wires inside of the sheath. You will have a red wire (the power wire) and a black wire (the ground wire). Leave the in-line fuse in the power adapter line that comes with your TomTom in place.








Then just connect the red wire to your 12v ignition on/off wire in the dome light, and your ground to the philips screw head ground connector beyond the dome light

 

hey thanks...

you are correct... 5v/ 2a.

so i can cut the cigar plug off?

after i do that.... expose the red and black wire, correct?

connect the red to the 12v lead and the black to ground.

then im done, correct?

i am confused with the last sentence. i dont need to worry about the inline fuse.. correct?

-Thanks

 

No, don't cut the cigar plug off of a TomTom as it runs at 5v 2a. If you do that, you'll be putting 12v to the GPS unit ; when it wants only 5v 2a.

You'll have to use the GPS cigar plug's internals ; with it's inline fuse as it's converting 12v into 5v 2a at the plug. Or ; use a Voltage Regulator which converts 12v to 5v 2a. Sorry I confused you - what I would do is just pop the plug open,( keeping the fuse in place ) - then wire that 12v line into the end of your cig plug for the gps - and the plug itself will convert your 12v connection (black with red stripe wire, right dome light harness) to 5v 2a for your GPS

You'll see the ground connection when you pop the dome light out. It's just beyond the dome light, up past the headliner:

 

okay.... first of all thanks for your help capthook!!!

so i took the cig adaptor apart and i only have one white wire. is this white wire the one i hook into the 12v connection (black with red stripe wire, right dome light harness)? no need for ground?

here are some pictures... both kinda crappy, so let me know if you need better ones.

-carino

 

VERY nice capt'n!

SMEEEEEEEEEE!

 

This is the most usefull thread I've seen in a while, awsome idea on the hardwire.

For those not looking to hard wire anything, I use a palm treo 680 with TomTom software, battery on my phone last about 10 hours. Wire free.

I have it paired with the Holux GPSlim 236, the unit is 1.5" in length, I hide it in the cigarette console, since I dont smoke :-))

On the navigation units, I really like this one.



Tomtom GPS Navigation System (GO 720)

I'm also digging everything about this next unit but the price, it's the future of nav units I think, an actuall picture of where you are. Give it 2 years or so.



Navigon 7100 GPS Navigator System

 

okay.... first of all thanks for your help capthook!!!

so i took the cig adaptor apart and i only have one white wire. is this white wire the one i hook into the 12v connection (black with red stripe wire, right dome light harness)? no need for ground?

here are some pictures... both kinda crappy, so let me know if you need better ones.

-carino



General rule of thumb with these cigarette adapters - is that the 'clips' or the metal sides of the cig. adapter are always ground, and the tip is positive. Wire in your connection to use that existing fuse in the cig. adapter and you'll be good 2 go with 12v input and it will convert that into 5v 2a.

A car adapter can be opened simply by using a flat head screw driver to the end cap, unscrewing the tip, and carefully pulling plastic sides apart (don't caveman it) . This will yield you a wire with a spring soldered to it, a wire with one of the metal sides soldered to it, and a fuse.

The wire that is attached to the spring (in this pic) is your +12v and the wire attached to the metal side is your 12v ground.