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Rap How-to On Nbs (keyed Accessory Power)

Diesail

By Diesail
in Audio, Electronics & Software

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Diesail Enthusiast

Diesail

Posted
Posted

The question of where to locate RAP (Retained Accessory Power) on the NBS trucks seems to come up often so I thought I would post this info for everybody.

RAP is available to us in the MBEC (Mid-Bussed Electrical Connector) located behind the instrument panel to the left of the brake pedal. The MBEC has 10 positions and the one we are going to us is X14. The problem is that RAP here is limited to only 300 milliamps but there are two other battery feeds in the location as well, one is 15 amps and the other 30. So to use the RAP power for anything but the smallest loads is going to require a relay.

Here are the parts you are going to need and the source that I purchased them from but they are available from many other sources as well.

 

3 Female GT 280 terminals Delphi Part number 15304711 Mouser part number 829-15304711

 

1 Relay pigtail Parts express part number 330-075

1 Bosch style relay Parts express part# 330-079

1 GM Connector 20791502 (optional)

 

Here is the relay harness, relay and connectors.

 

wol_error.gifThis image has been resized. Click this bar to view the full image. The original image is 800x471 pixels and 37KB in size.RAP_Relay.jpg

 

There are 5 wires in the harness connected as follows.

 

White wire – Relay trigger positive – relay pin 85

Black wire – Relay trigger ground – relay pin 86

Blue – Constant 12v source – relay pin 30

Yellow – NO (normally open) circuit – relay pin 87

Red – relay pin 87a, this wire is not used and needs to be removed.

 

You will need to install the female terminals on the white, black and blue wires. Since I elected not to spend money for the GM Connector I went ahead and covered my connectors with shrink wrap. I may still pickup2_bing.gif the connector but needed to get this done and hadn’t had a chance to get to the dealer and didn’t want to pay GMPartsDirect their freight charges. Here are my finished cable ends.

 

wol_error.gifThis image has been resized. Click this bar to view the full image. The original image is 1024x833 pixels and 54KB in size.RAP_Connectors.jpg

 

Remove the cover to the MBEC, it looks like this

 

wol_error.gifThis image has been resized. Click this bar to view the full image. The original image is 761x508 pixels and 43KB in size.RAP_Cover.jpg

 

Here is a diagram of the MBEC connectors; we need to use X14

 

RAP_MBEC.jpg

 

A close-up of X14

 

RAP_X14.jpg

 

The connections will be as follows

 

White wire to Pin 8 - RAP feed

Black wire to Pin 1 - Ground

Blue wire to Pin 2 or Pin 5. Pin 2 has 15 amps which was plenty for my needs. Pin 5 has 30 amps. - Battery feed

 

The remaining yellow wire will feed your accessories.

 

Enjoy….

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Diesail
Diesail

The question of where to locate RAP (Retained Accessory Power) on the NBS trucks seems to come up often so I thought I would post this info for everybody. RAP is available to us in the MBEC (Mid-Buss

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mfennema Enthusiast

mfennema

Posted
Posted

Great write-up. Nice to see it all with pictures. Only thing I would add is that you should put a fuse in the main power line for safety.

 

Excellent work!!

Diesail Enthusiast

Diesail

Posted
  • Author
Posted
Great write-up. Nice to see it all with pictures. Only thing I would add is that you should put a fuse in the main power line for safety.

 

Excellent work!!

 

 

The two circuits outlined are part of the provisions for upfitters and are already fused at the 15 and 30 amps described. In my installation the output from the relay feeds an accessory fuse block giving me four fuse locations with a total of 15 amps available. Currently I am powering two items, a GPS and a cigarette lighter output that is RAP instead of always on.

Harvey Halabookie Enthusiast

Harvey Halabookie

Posted
Posted

Thanks for the great write-up. I hardwired my Sirius radio yesterday following these directions. I also used the hardwire install kit from TSS Radio as well as one of the noise filters they sell. It sounds great now with none of the noise I had when it was hooked into the cigarette lighter.

khancock Enthusiast

khancock

Posted
Posted

Do you happen to have the part number for the GM connector? I have no idea what this costs and would like to look into this option. Thanks!

Diesail Enthusiast

Diesail

Posted
  • Author
Posted
Do you happen to have the part number for the GM connector? I have no idea what this costs and would like to look into this option. Thanks!

 

1 GM Connector 20791502 (optional)

 

It lists for only $12.10 and I almost ordered it from GMParts direct but with there shipping price went up to $24 bucks. Since I hadn't made it to my dealer to order and I needed to get the project done I elected to finish without it. I may order one next time I'm in the dealer and peel the heat shrink and install it just to make it look a little more complete. The connector comes with only a single wire in the ground positions so you still need the other parts.

khancock Enthusiast

khancock

Posted
Posted
Do you happen to have the part number for the GM connector? I have no idea what this costs and would like to look into this option. Thanks!

 

1 GM Connector 20791502 (optional)

 

It lists for only $12.10 and I almost ordered it from GMParts direct but with there shipping price went up to $24 bucks. Since I hadn't made it to my dealer to order and I needed to get the project done I elected to finish without it. I may order one next time I'm in the dealer and peel the heat shrink and install it just to make it look a little more complete. The connector comes with only a single wire in the ground positions so you still need the other parts.

 

 

Thanks, I guess it would help if I read the entire dam post next time! :lol:

silveradope Enthusiast

silveradope

Posted
Posted

Awsome post!!

very easy to understand. thanks for the pictures too!

I will be installing my xm radio into my truck soon and needed this info.

Thanks for taking the time to do this for everyone!!!

  • 2 weeks later...
mopester Enthusiast

mopester

Posted
Posted

Thanks for the great write up. I'm going to install headrest monitors using your instruction. I have one question. Am I supposed to connect both red and black power wires from the headrest monitors to the yellow wire? Thanks for your help.

Awsome post!!

very easy to understand. thanks for the pictures too!

I will be installing my xm radio into my truck soon and needed this info.

Thanks for taking the time to do this for everyone!!!

Diesail Enthusiast

Diesail

Posted
  • Author
Posted
red and black power wires from the headrest monitors to the yellow wire?

 

Without seeing the directions for your monitors I would guess that the black wire is ground. If so then no, only the red wire to yellow. Also anything connected to the circuit should be fused.

mopester Enthusiast

mopester

Posted
Posted

Thank you so much for your quick reply. There is a fuse on the wires coming from the headrest monitors. I'll give it a go and let you know how it turns out in a few days.

red and black power wires from the headrest monitors to the yellow wire?

 

Without seeing the directions for your monitors I would guess that the black wire is ground. If so then no, only the red wire to yellow. Also anything connected to the circuit should be fused.

 

Bill in Niantic Enthusiast

Bill in Niantic

Posted
Posted
The question of where to locate RAP (Retained Accessory Power) on the NBS trucks seems to come up often so I thought I would post this info for everybody.

RAP is available to us in the MBEC (Mid-Bussed Electrical Connector) located behind the instrument panel to the left of the brake pedal. The MBEC has 10 positions and the one we are going to us is X14. The problem is that RAP here is limited to only 300 milliamps but there are two other battery feeds in the location as well, one is 15 amps and the other 30. So to use the RAP power for anything but the smallest loads is going to require a relay.

Here are the parts you are going to need and the source that I purchased them from but they are available from many other sources as well.

 

3 Female GT 280 terminals Delphi Part number 15304711 Mouser part number 829-15304711

 

1 Relay pigtail Parts express part number 330-075

1 Bosch style relay Parts express part# 330-079

1 GM Connector 20791502 (optional)

 

Here is the relay harness, relay and connectors.

 

wol_error.gifThis image has been resized. Click this bar to view the full image. The original image is 800x471 pixels and 37KB in size.RAP_Relay.jpg

 

There are 5 wires in the harness connected as follows.

 

White wire – Relay trigger positive – relay pin 85

Black wire – Relay trigger ground – relay pin 86

Blue – Constant 12v source – relay pin 30

Yellow – NO (normally open) circuit – relay pin 87

Red – relay pin 87a, this wire is not used and needs to be removed.

 

You will need to install the female terminals on the white, black and blue wires. Since I elected not to spend money for the GM Connector I went ahead and covered my connectors with shrink wrap. I may still pickup2_bing.gif the connector but needed to get this done and hadn't had a chance to get to the dealer and didn't want to pay GMPartsDirect their freight charges. Here are my finished cable ends.

 

wol_error.gifThis image has been resized. Click this bar to view the full image. The original image is 1024x833 pixels and 54KB in size.RAP_Connectors.jpg

 

Remove the cover to the MBEC, it looks like this

 

wol_error.gifThis image has been resized. Click this bar to view the full image. The original image is 761x508 pixels and 43KB in size.RAP_Cover.jpg

 

Here is a diagram of the MBEC connectors; we need to use X14

 

RAP_MBEC.jpg

 

A close-up of X14

 

RAP_X14.jpg

 

The connections will be as follows

 

White wire to Pin 8 - RAP feed

Black wire to Pin 1 - Ground

Blue wire to Pin 2 or Pin 5. Pin 2 has 15 amps which was plenty for my needs. Pin 5 has 30 amps. - Battery feed

 

The remaining yellow wire will feed your accessories.

 

Enjoy….

 

 

I went to many local shops, including GM Dealer. Nobody carried Delphi 15304711-L. I had to order it on the Mouser Site and pay the "shipping". But I bought 6 instead of 3, for the next project whenever it happens, or if I screw it up.

wild willy Enthusiast

wild willy

Posted
Posted

Is this the same type of connector plug that is used when installing a trailer brake? I recall someone else on one of the forums calling out another plug supplier for that part-

 

Thanks for a great, clear write-up. I think even I can follow these directions ;^)

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