Retained Access Power

TonyMazz · October 24, 2005

Since the RAP Class 2 signal pulses has anyone every hooked up an aftermarket radio, or other equipement that stays on after the ignition is turned off ?

From what I can tell the class -2 signal pulses at 10.4 bps and rides on a 7 volt dc ....am thinking of a circuit that would get the message, and then stay on with a micro relay driving the 12 battery voltage, but not sure...

Some one on this board must have mastered the RAP for after market stuff....

mmmikkke · October 27, 2005

Since the RAP Class 2 signal pulses has anyone every hooked up an aftermarket radio, or other equipement that stays on after the ignition is turned off ?

From what I can tell the class -2 signal pulses at 10.4 bps and rides on a 7 volt dc ....am thinking of a circuit that would get the message, and then stay on with a micro relay driving the 12 battery voltage, but not sure...

Some one on this board must have mastered the RAP for after market stuff....

<{POST_SNAPBACK}>

The Metra GMRC-01 and GMRC-02 units do this. They have a relay, I think, and their purpose is to provide RAC to aftermarket radios.

I have the GMRC-02 ($70) and mine is hooked up to a Pioneer in-dash unit. Works pretty much like the factory radio did (but of course since it's not a GM radio, it sounds a lot better).

If I had it to do over again, I'd get the GMRC-01 so it doesn't try sending the chime signal to the front left speakers. I'd rather have the chime come through the cheezy 2.5" speaker built into the GMRC-01.

TonyMazz · October 28, 2005

yeah I checked them out but they say they won't work with a 2004 tahoe...

GM-Tech · October 28, 2005

Is it safe to assume you don't have a sunroof? Even if not, the controlling circuit is probably still there in the BCM. I haven't actually checked, but it seems likely. In that case, you'd only need a relay to tie into that pin on the BCM to have it controlled by RAP. Then, the relay could power whatever you want to be on RAP.

TonyMazz · October 28, 2005

Is it safe to assume you don't have a sunroof? Even if not, the controlling circuit is probably still there in the BCM. I haven't actually checked, but it seems likely. In that case, you'd only need a relay to tie into that pin on the BCM to have it controlled by RAP. Then, the relay could power whatever you want to be on RAP.

<{POST_SNAPBACK}>

Any more specifics will help....wire color etc....

GM-Tech · October 28, 2005

Any more specifics will help....wire color etc....

Connector 2 on the BCM, which is a gray, 24 pin connector, terminal B3. The wire is dark blue if you had a sunroof. Without a sunroof, there may not be a wire in the connector in that cavity, but the pin should be in the BCM.

It's only meant to control a relay, so I wouldn't try to power up something major directly on that pin.

99-2door · November 2, 2005

I can comfirm that the sunroof circuit, does work... I used it to power the Xm adapter on my brother's 2003 Tahoe. It does not have a sunroof, but the BCM still activates that wire. I can't remember if I had to add the pin to the plug or if it was already there. Kinda thinking I had to add it.

TonyMazz · November 3, 2005

So then the BCM connector 2 Gray 24 pin connector pin B3 which is circuit 1353 RAP supply voltage feeds over to the sun roof.

GM-Tech is this a pulsed voltage ? I can't simply hook up this to my Sirius radio power directly right ?

By your last response I was thinking a micro relay and find a 12 volt source to actually power the radio. But then the gentlemen above states he powered his XM directly from B3....

I was thinking that the B3 RAP signal was a small pulsed signal of a few micro seconds in duration on top of a 7 volt dc signal. using a micro relay to the one side to open the 12 volt supply voltage on the other to feed my sirius radio...I don't know what the draw is but suspect its a few millamps....

Thoughts ?

Sierra 05 · November 13, 2005

So then the BCM connector 2 Gray 24 pin connector pin B3 which is circuit 1353 RAP supply voltage feeds over to the sun roof.

GM-Tech is this a pulsed voltage ? I can't simply hook up this to my Sirius radio power directly right ?

By your last response I was thinking a micro relay and find a 12 volt source to actually power the radio. But then the gentlemen above states he powered his XM directly from B3....

I was thinking that the B3 RAP signal was a small pulsed signal of a few micro seconds in duration on top of a 7 volt dc signal. using a micro relay to the one side to open the 12 volt supply voltage on the other to feed my sirius radio...I don't know what the draw is but suspect its a few millamps....

Thoughts ?

<{POST_SNAPBACK}>

I installed my Kenwood with the GMRC-01 and the sSWI-X steering wheel control interface. Both work great. I did retain the door chime with the radio interface, and everything works like it did the day I bought it. I talked to Best buy and Circiut CIty before, and both told me you have to keep the factory radio in place, in order for the circuits to work properly, like the dash cluster, ignition. FALSE Talked to Crutchfield about this, and since they install everything they sell, they would know a little more than the others.