navtool/backup camera questions..

[TerminatorX5]

we need to figure out where you can pick up a reverse signal without going to the reverse lights... let me check into something...

[Turbo_Bimmer]

Originally Posted by TerminatorX5

we need to figure out where you can pick up a reverse signal without going to the reverse lights... let me check into something...

I didn't try it, but feeding the pulsating signal of the backup light through a diode to isolate it, then feed a relay coil with a big capacitor in parallel should work.
The value of the capacitor will depend on the duty cycle of the PWM signal and current draw of the relay coil.

BTW, having a PWM signal at the backup lights make them light dimmer than a full 12V, why would BMW do that?

[pw44]

Originally Posted by Turbo_Bimmer

I didn't try it, but feeding the pulsating signal of the backup light through a diode to isolate it, then feed a relay coil with a big capacitor in parallel should work.
The value of the capacitor will depend on the duty cycle of the PWM signal and current draw of the relay coil.

BTW, having a PWM signal at the backup lights make them light dimmer than a full 12V, why would BMW do that?

Could you please explain? I also have the idea to hook from the reverse light the positive to the relay, and was also thinking to have a 6800 uF 50V connected to the relay coils. Do i need the diode?

The 6800 uF 50V capacitor i did use on my led tails lights which were flickering due the pwm and it solved the flickering.

[Turbo_Bimmer]

Originally Posted by pw44

Could you please explain? I also have the idea to hook from the reverse light the positive to the relay, and was also thinking to have a 6800 uF 50V connected to the relay coils. Do i need the diode?

The 6800 uF 50V capacitor i did use on my led tails lights which were flickering due the pwm and it solved the flickering.

Do you have the LED tail lights + capacitor right now?
If yes, hooking up a relay (with high coil resistance) should work since the PWM signal would already be smoothed by the big capacitor.

If you still have the incandescent bulbs, the reason for the diode is to isolate the charged capacitor from the low resistance of the bulb, so that the capacitor remains charged in between the 12V pulses.
The LED bulbs draw a lot less current than the incandescent bulbs, so a diode may not be necessary.
I will experiment with that in the next month(s) because I want to install a camera, Navtool + portable DVD.

[TerminatorX5]

what year is your car? month/year?

you can pick up the reverse signal from the indicator lamp from the gear selector indicator, where it says "P", "R"...

You will have to use a small electronics relay, not the 40A relay - you can pick one from the Radio Shack for a few bucks... The current in the indicator light is very small, it will not be enough to drive a big relay, just enough for a small relay... i have posted the spec sheet for the one I am talking about...

Pin 3 on the connector X1599 has the reverse light signal.

[euge]

2005, mfd aug 05

[TerminatorX5]

here is a possible option for connecting the trigger wire to the reverse lights that are "pulsating" with the PWM:
H3FA-AU-DC12V Omron Electronics Inc-IA Div | Z3012-ND | DigiKey

this is a time-"delay off" latching relay, from Digi-Key. they sell it for about $50 a pop, but it might be the solution that the folks without the PDC might need.

Are there any electrical engineers outhere that can collaborate on this specs with me?

[euge]

What spec relay should i pick up from radioshack? Also, what would be the easiest way to gain access to the shifter light? Once i am finished with this project i will post a complete guide on the process!

[TerminatorX5]

this is a spec sheet for relay - radio shack has only one type of the variations, so you can't go wrong.

the skirt can be lifted - i haven't done it myself but there are other threads that might say how to get to shifter

[euge]

Picked up the relay from radioshack, considerably smaller than a standard automotive relay lol. there's 5 pins on the relay and looking at the data sheet you posted, which pins would be 30, 85, 86, 87?