I heard I need to have one momentary button to simulate brake pedal switch and a switch to simulate parking switch. Is this correct? It would make installation easier too if I don't have to hunt for these wires on the car.

 

someone once told me that you can just ground the wire on the HU that normally hooks to the brake switch.

 

You were told correctly. The foot brake needs to be connected to a 12v source and the hand brake to a ground.

 

According to the diagram Alpine gave me, both seems to need +12V.

 

Hmm... they must have made changes from the earlier iva and cva models. The 1004, 1005, 1006, c800, and c801 all needed 12v for the foot brake and a ground for the hand brake. If you have tech sheets from Alpine, by all means, I'd follow those. I have not installed the d300 yet, so the information that I gave is from what I know of the older units and what I've been told.

 

My CVA-1005 needs a 12v for the foot brake and a ground for a hand brake. If yours is the same then get a PAC TR-7 module. It will automatically send each wire the pulse that it needs everytime you start the car so you don't have to mess with the switches everytime you start the car.

 

Oh man..I didn't know about the PAC TR-7 module. Oh well...now I got a cool push button and switch on my dash. I'll take some pics tomorrow and post them.

 

So, tell us, how did you end up wiring the switches?

 

sounds like he did.
now let's see some pictures!

 

Yeah, I see where he got it up and running. I'm curious as to whether or not he wired the thing up as we suggested or went the other route.

 

I'll take some pictures tonight. People were right. The momentary button to simulate brake pedal switch is +12V and the switch to simulate parking switch is negative ground sensing. I read the freaking diagram wrong at first. Anyway, it took me total of 12 hours to get it right. I made several wiring mistakes. I got constant +12v mixed up with ACC +12V. Way too many wires and I got all confused. The wire to sense the ground on the parking brake switch must be really low current because it wouldn't even light up the cool little LED on my switch. Damn it..maybe I forgot to hook up the ground wire for light.

 

im trying to wire up the iva d300.....so does the foot brake getting the 12v go to a constant 12 or and accessory or does it matter

 

Accessory +12V or constant +12V both will work. Since you are supplying the +12V momentary, it won't draw anything when the car is off anyway. I believe I wired mine to constant +12V.

 

thanks man....also with your ground wire...did you just solder it in with the ground wire coming out of the brain or did you give it, its own metal ground.

 

also does the ground wire need to be hooked to a switch to be pulsed or can it be grounded all the time

 

The ground needs to be switched and you can use the same ground that the head unit uses.

 

It needs to be switched. Grounding it all the time won't work. Basically, the unit is looking for

1. You to step on the brake pedel and hold it. (The momentary button +12V)
2. Pull up the parking brake. (The switch ground).
3. Letting the parking brake back down. (interrupt the switch ground)
4. Then pull up on the parking brake again (The switch ground).
5. Then let go of the brake pedal. (interrupt the m+12V)

As you can see, grounding it all the time you won't able to interrupt the switch ground.

 

1MAX2NV, DougJones, i'm from the philippines so i'm out of luck with the PAC-7 or even the "black box" modules..

can i have a detailed procedure of what you did? or maybe a diagram if possible?

 

Just do it as 1max2nv explained above your post. one switch for +12v and one switch for ground. basically, turn on the 12v then flip the ground on-off-on then turn off the 12v.