I'm building a car-pc and need a way to trigger my double din screen to turn on. I decided to do this by using a simple bosch relay connecting to something that turns on/off with the ignition. Couple of questions...

1. What is the best way of doing this? Is a fuse tap the preferred method to get a +12v signal when something tied with the ignition turns on?

2. Noob question but, what should I use as a trigger? I'm thinking something like the fuse for the heated seats since my car doesn't come with them from the factory.

All replies are useful.. thanks in advance.

 

if youre just looking for a signal, there are good wires coming from the ECU that will have what youre looking for

 

That sounds good but the ECU isn't something I want to mess with for a DIY job

 

Cig lighter ...

 

Doesn't the cig lighter come on as part of the ACC circuit

 

Do it from the 12v from the carPC PSU. I ran a wire on the power side of the vehicle from my PSU back to my screen.

What setup are you running btw?

 

what difference does it make? unless you spend a lot of time in the car with just the ACC on, it would be the same

 

Don't have a dc-dc psu yet, I initially thought about using an inverter but apparently there's too much interference. Still in the planning stages

My setup is the following:
lilliput eby701/gxe bezel
Centrafuse 3 Frontend
2GB DDR2 pc6400
amd x2 5000+ @2.2ghz (65w)
auzen x-fi prelude 5.1 tapped into the stock bose amp until I get a new amp/speaker set up/ also tied into 300w kenwood mono amp/alpine sub

what about you?

 

Shuttle K45 Barebones
Intel Core2Duo Processor (35w), 2GB RAM, 160GB 2.5" HDD
Opus 150W Shuttle DC-DC PSU
Lilliput EBY710 7" Touchscreen in Bybyte Double-DIN Enclosure
Santa Cruz Sound Card to Metra Harness to Factory Bose Speakers
OEM GXE Dash Trim

The Opus has three wires, which is easy. One for positive (runs to battery with fuse), One to ground (right in the trunk) and One for remote to trigger it on (runs to fuse in box near hood release). The screen has a power connector wired to two wires that run back to the Opus into one of the 12v connections. It's regulated that way, rather than 14-15v you'll get somewhere on the car.

Let me know if you have more questions.

 

Tell me more about that sound card->metra harness setup, sounds like it makes life a hundred times easier

 

If I recall correctly, its the 70-7551? The one that provides two pairs of RCA inputs. You use those. So let me break it down...


5.1 Sound Card gives you Front and Rear sound channels in 3.5mm ports >

3.5mm to RCA adapter for each port gives L & R > RCA cables (2) > RCA Male to Male Adapter >

Metra Harness 70-7551 > Stock Harness.

 

I recently just hot-wired my Radar to a switched 12v directly off the fuse block. Mine's a 2003, but I assume they are similar. 2003 fuse block has 3 open circuits. All 3 are 12v+ switched with ignition. I am running a 15 amp fuse in that location, then a standard bus fuse in the radar wire.