2005 GMC Sierra RAP Relay Location

hello,

     i am new to the forum and i am sure someone probably have asked this question before, but i need some direction on the location of the rap - relay so i can switch it out.  i have been having issues with  my truck dying out after 2 or 3 days of not starting it up.  i have disconnected the amps and even the fuse to the battery power cable and it still dies out.  recently i have encountered problems with the radio staying on when i open the doors and take the key out.  it doesnt happen all the times but it does here and there.  when it does i have to start the truck back up and close the door and turn it off and open the door back up to cut it off.  this weekend that didnt work and i had to wait on it to cut off on its own. 

    i checked in the fuse box under the hood, the fuse panel on the drivers side dash board, the panel by the brake pedal, and the wire harness that is considered the bcm.  no luck finding any relays for the rap i purchased from autozone.  i called the dealer and they told me they dont have any wiring documentation that will help locating the rap relay.  i see diagrams online for the wiring but none of those diagrams point to anywhere else besides the fuse box which i checked repeatly. 

 any help will be greatly appreciated as i have been at this for a week,

thanks...

https://www.automotiveforums.com/t931989-rap_relay_location.html

joegene6312-06-2008, 12:11 PM
Answering my own question in hopes this helps somebody else.
The RAP (Retained Accessory Power) relay is on the passenger side on the right hand side.

Note: I was looking into this relay since my power windows (passenger and driver) were not working. It turns out the relay was fine. The problem was the wire that feeds the power to the passenger and driver side window switches. GM spliced this wire so that the single wire splits into 2 wires - 1 for passenger the other for the driver side. This splice is located on the floor by the passenger side door. Overtime the carpets got wet and this splice was sitting in water and slowly the splice corroded. There was another splice beside it that was corroded, which fixed my rear quarter panel power windows. These splices are definitely a weak spot in the wiring harness and the fact they are under carpet that gets wet only makes it worse.

Also Check Here https://www.the12volt.com/installbay/forum_posts.asp~TID~49157

The BCM (Body Control Module) is under the driver side dash. It has 6 plugs in it, the purple plug is on the back.I think the R A P Relay is inside of the BCM.

https://www.gm-trucks.com/forums/index.php?showtopic=97615

-------------
John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Also check your ignition switch.

-------------
Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

A Little Electrical Spray goes a long ways. Excellent Idea Howie II.

-------------
John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Thanks for the hlpe, but I broke after weeks of no resolution and checking all over the place and brought the truck to the local electronic shop i have dealt with in the past with other vehicles.  After 3.5 hours of diagnotics time, the issue was with the factory amp was staying on.  I had a aftermarket radio installed shortly after getting my truck back in '05 and I think I purchased the wrong PAC 02 unit.  We forgot to disconnect the factory amp's power and ground back then and I rarely went days without driving it back then.  I will find out for sure if that was the problem because I am out of town and wont be back for 4 days and get back to the forum.  BTW the factory amp is under the middle console in those trucks for those that didnt know.

I would have never guessed that one.

This is one for the X-files of Problem solving.

-------------
John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

The number one diagnostic problem, they never tell you the full story.
Scirocco 20 years ago and the locks aren't working on the passenger door. Can't find any thing wrong in the car, ring the customer, has this car been in for accident repairs?
"Yes"
"Passenger door, how did you know".
"OK sir come and get your car in an hour"
Popped the door panel and refitted the vacuum tube the body fitters had forgotten.

-------------
Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

How about this. I had a customer with an extended cab 2005 Chevy Silverodo. The power windows would only operate while the truck was running. they would not operate in the ingnition or accessory position. Every thing else worked fine. It was a pain to tint the front door windows because I had to leave the truck running in the shop while I did the job.( The windows have to be rolled up and down durring a window tint job) Since I do 12volt auto installs and repairs I tried to figure out what was wrong with the truck but I had no luck. I figured I had to do with the rap system. But it was hard to tell since it had an aftermarket stereo system installed, along with amps box ect. The stereo turned off with the key, didnt stay on untill the door opened.

-------------
Solartech Window Tinting and Electronics,contract installer

For future reference, RAP is serial data controlled. The following is from the repair manual.

Repair Manual wrote:

---

RETAINED ACCESSORY POWER (RAP) DESCRIPTION AND OPERATION

Serial Data Control of Retained Accessory Power (RAP)

The class 2 modules receive the power mode message from the body control module (BCM) over the serial data circuits, indicating when the retained accessory power (RAP) power mode is current. The BCM monitors the ignition switch position, battery condition and passenger compartment doors status to determine whether RAP should be initiated. The modules then support the operation of the systems under their control as required by their RAP power mode operation.

RAP will end when one of the following conditions is met:

• The BCM receives an input indicating the opening of any compartment door.


• The BCM internal timer for the RAP expires after approximately 10 minutes.


• The BCM detects a decrease in battery capacity below a prescribed limit.

The BCM then sends a serial data power mode message Off-Awake ending the RAP function.

The class 2 RAP functions are:

• The power windows


• The radio

---

-------------
This information is provided only as a reference.
All circuits should be verified with a digital multi-meter prior to making any connections.