Which fuse to hardwire V1?

Jgordon · 02-05-2005, 05:58 AM

I spoke to my wrench, and he suggested that rather than crimp onto a wire under the dash, I should go straight to the fuse box in the trunk to hardwire the V1s power source. I'm looking for a 12 volt lead that's hot when the car's on, and is not too essential in case of a short. Any good suggestions? Also, any thoughts on the best way to lead off the fuse would be welcome.

Thanks,

wilke3169 · 02-05-2005, 06:08 AM

I attached mine to the cigarette lighter fuse. Not sure of the number but it does operate with the key.

scottb · 02-05-2005, 06:52 AM

Contrary to what your wrench said, if it were me I'd tap into the lead to the radio, but I'd be sure to have an inline fuse for the V-1.

Jgordon · 02-05-2005, 08:42 AM

Definitely has an inline fuse. Cigarette lighter is a good idea, but would that get overloaded if I then plug a cell phone into the lighter itself?

Also, dumb question - does it matter whether I put the wire for the V1 into the top or the bottom of the fuse wiring?

Thanks.

Quicksilver · 02-05-2005, 10:13 AM

Is your wrench used to working on Porsches? If not he would be shocked to find that the controls on the dash have UNFUSED power. For some reason Porsche puts the switches between the battery and the fuses. The fuses are just before the load in the circuit.

Weird. . .

Wayne

randywebb · 02-05-2005, 10:22 AM

3M makes a little T-tap thing & the V1 comes with that (at least mine did). You can get them at Radio Shack, etc. if not a hardware store.

Check the current draws on your manuals or stickers on the units and add them up to see if the fuse will handle it. Include a saftey factor for spikes.

In some years, I think the cig. lighter is on all the time. Probe it to be sure.

t.brady · 02-05-2005, 11:35 AM

I agree with scottb. I tapped into the radio lead then soldered a small fuse, I believe it was a 5A, into the V1 lead. Careful when probing anything related to the dash circuitry, badly scorched wire or even a car fire could result. I soldered a fuse into the dash circuitry as well. I believe it's the 59A post on the headlight switch, should be the same in your car.

Jgordon · 02-06-2005, 07:17 PM

Well this was much easier than I had thought - it was my first electrical venture, and visions of frying my DME were dancing in my head. I pulled out an early-mid-nineties nokia hands-free system (charging jack, speaker, mic), which freed up some space and took some wiring out. That left crimp leads from the radio - power and ground. I just ended up cutting off the fork-lead for the V1 grounding wire and crimping on a spade and jacket connector, and re-using the phone system leads. Even stuck the V1 accessory Y-jack to the back edge of the cruise control module, making it neat and out of the way.

Next up, I'm going to pull the old K40 radar system out. Thanks for all the tips.