hardwire - which fuse to use

**scruffymmh** · 04-01-2007, 01:42 PM

I just bought an x50 and ordered a direct wire yesterday. I want to hard wire to my 2007 jetta's fusebox next to the driver's side. I know we usually tap into the radio fuse, but that's actually in a separate fuse box under the hood. I'd rather tap into the fuse box inside the car, for convenience purposes. I've got a few fuses in there that might work: "Power Outlet" (i think that's the 12V in the center console) and "Cigarette lighter" (probably the 12V cig lighter), as well as some others. I figure one of those two should work fine, but should I be concerned about overloading the circuit if I plug something into the 12Vs (cell phone charger for instance)?

I have pictures posted of the fuse diagram from the drivers manual as well as a photo I took of the fuse box. the jpegs are posted at http://www.hulihan.net (not a commercial site; it's just my own machine with those pictures posted)

Any recommendations would be much appreciated. Thanks!

**batwings** · 04-01-2007, 02:28 PM

Like you stated above: power outlet or cigarette lighter would be fine. cell phones dont draw ALOT of current even when dead.

IF cigarette lighter fuse (25A) blows... replace and go to power outlet...

**thestaton** · 04-01-2007, 02:39 PM

I was use IGN or ACCS fuse.

**scruffymmh** · 04-01-2007, 02:51 PM

cool. thanks, I'll probably try the cig lighter.

Any idea if the "Vacant"s are ever charged? Ignition-switched?

The add-a-circuit comes with the proper fuse to use for the RD correct?

**thestaton** · 04-01-2007, 02:58 PM

just get the add a fuse. put it in the IGN / ACCS they are usually open. good to go.

**STEEDA77** · 04-01-2007, 03:53 PM

For the VW... I use the 75X terminal. This will have power when the car is running.

Look up under the dash, there may be a panel that you may have to pull off to get to it.

**spyder2000** · 04-02-2007, 07:00 AM

From my radio transmitter installation experience: fuse both leads.

If the negative lead from the battery to the starter/engine fails or becomes high resistance for whatever reason, the electrical system will search for another ground path. The RD or its' power circuit could become that.

If this happens, in all probability your wiring will go first but if it doesn't... and you can easily get by with an inline fuse holder on the negative lead.

**Orbital75** · 04-02-2007, 08:06 AM

I have a 2004 Jetta, here's how I did mine.

I used a " FUSE TAP " on the 15 amp " Accessory " (cigarette lighter ) fuse.
Then ended up cutting the Blade part off the Hardwire and replaced it
with a female connector that would slide right into the fuse tap.

The Ground wire is under the dash bolted to the firewall.

I do like the "Add A Fuse" connector but at the time didn't know about
them. I would try that instead. I believe that they Max out at a 10 amp fuse but I would just insert a 15 amp just like what suposed to be in the Acc slot. I doubt very seriously it would hurt anything.

My Current Wiring

**scruffymmh** · 04-02-2007, 10:07 AM

Thanks for input so far...On the VWs there's the 75x tap which is appealing but then I'd have to worry about fusing the Direct Wire. Does anyone know if the Direct Wire (plain, NOT the smart cord) has a fuse built in? if I go into the 75x I'd probably want to fuse the positive... Another consideration is whether my tapping into the 75xor fuse box will give me warranty problems since I lease my car....

I'm looking at the add-a-fuse too. I don't have an ACC, Radio, or IGN fuse in the fuse box by the drivers side. Those are under the hood in a separate fuse box. I'd probably put the add-a-fuse in the cig lighter. My cig fuse is 25 amp though, so can i just put the add-a-fuse into that cig slot, put the 25amp cig fuse into the add-a-fuse, and leave the 10amp fuse it comes with in there for RD? [If the cig ever gets over 10amp from the battery which is likely, right, since there's a 25amp in there now? My add-a-fuse is gonna blow if that's the case, yes?]

**Orbital75** · 04-02-2007, 11:37 AM

I spoke to a Stereo installer that stated that when they do Radar Detector installs that they will use a higher amp fuse in both slots of the "Add A Circuit". He said that it's never caused a problem or blown a fuse. However, Just don't go too high. 25 amps is about all I would try to push with it.
Also don't go higher then what was already in the location.