Afterblow / Electronic Evap Dryer module install

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nick0789

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With the summer temps brings back the dreaded “musty AC” in my 2005 tahoe. After reading, I found I can do a cabin air filter retrofit. I got the hole cut out and am just waiting for the filter and panel to arrive so I figured I’d ask about afterblow now.
I also ordered the afterblow module but the instructions that I can see in the pictures online look like they will be vague. Is there a writeup somewhere on this forum for installing the module, or will the instructions actually be decent enough to follow?
Or does the NBS have the feature built in and just needs activating with a techII?
 
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nick0789

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I got the module in the mail and had questions regarding the wiring. Wiring is admittedly not my strong suit so I want to be sure of what I’m cutting before going at it.

Red: to constant 12V supply —> what behind the dash can I tap into? The wiring diagram shows the wire being run straight to Battery+ but the instructions say to use a supplied connector, which wouldn’t work with connecting straight to the battery

Black: straight to a ground source (wired last)

Green: splice into ground wire of blower motor —> this is the black wire correct? There are only two wires going to the blower

Blue and Yellow: cut the burgundy wire going to the blower and connect the blue and yellow wires to the respective ends of that cut wire.

The red and black wires are the longest, so I know the module is going to have to be housed somewhere behind the passenger dash. If I need to go through the firewall to connect straight to the battery, where can I run through? I haven’t had a chance to look for boots or anything yet.
 

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Rocket Man

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I got the module in the mail and had questions regarding the wiring. Wiring is admittedly not my strong suit so I want to be sure of what I’m cutting before going at it.

Red: to constant 12V supply —> what behind the dash can I tap into? The wiring diagram shows the wire being run straight to Battery+ but the instructions say to use a supplied connector, which wouldn’t work with connecting straight to the battery

Black: straight to a ground source (wired last)

Green: splice into ground wire of blower motor —> this is the black wire correct? There are only two wires going to the blower

Blue and Yellow: cut the burgundy wire going to the blower and connect the blue and yellow wires to the respective ends of that cut wire.

The red and black wires are the longest, so I know the module is going to have to be housed somewhere behind the passenger dash. If I need to go through the firewall to connect straight to the battery, where can I run through? I haven’t had a chance to look for boots or anything yet.
The main harness goes through the firewall through a huge grommet on the driver side, I have run a wire through it by cutting a hole on the side of it a little ways away from the main harness. You’ll still need to stick something through to fish it through and I would pull the knee bolster so you can see to tie it up away from the brake and gas pedal as well as any other obstacles.
 
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nick0789

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Update: still haven't installed it yet. I've been fighting a flooded passenger floorboard thanks to this rain we got from Elsa. I'm hopeful that I tracked it down to the cowling area and the plastic covers.

I figured that I would have to place the harness in the engine bay to get to a good ground and battery+ but the yellow, green, and blue wires are not long enough for me to do so. I could solder more wire to them if needed, but the [very] limited forum posts I've seen everywhere else online (corvettes, etc.) show the module going up under the glove box.
Is the 12V constant plug in my center console sufficient for tapping into? It runs through a 20A fuse, which would satisfy the "20A minimum" listed in the diagram, but I don't know if it would meet the need listed in the "Wiring Connection" section.

This kit is frustrating because it is intentionally vague so the module can be applied to multiple GM models, but the splicing connectors supplied with the kit also wouldn't seem like I could cut a hot wire and splice with the provided red wire. It's almost set up to where I need to install a lug myself (which I haven't seen done online), or find some random hot wire that isn't connected to anything.
 

S33k3r

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Is the 12V constant plug in my center console sufficient for tapping into? It runs through a 20A fuse, which would satisfy the "20A minimum" listed in the diagram, but I don't know if it would meet the need listed in the "Wiring Connection" section.
I would think not, because 20v minimum means nothing else could be drawing power on that circuit when your blower is running.
 
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nick0789

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Thanks for the heads up. Do you know of anything off-hand behind the dash then that I could potentially tap into?

I had emailed GM about it and never got a response.
 

Rocket Man

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The afterblow wouldn’t be turned on unless everything else is turned off though, correct? Doesn’t it come on after the truck is turned off and sits for a few minutes? That console power is likely the 12v accessory outlets so as long as you don’t have something plugged in there (which would drain your battery regardless) I would think it would be fine. You would know if you’re drawing too much because the 20a fuse would blow. I say give it a shot. Worse case is you blow that fuse and then you’d be back where you started.
 

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