DIY: Electric Exhaust Cutouts

ELECTRIC EXHAUST CUTOUTS

This article will show you how to install an electric exhaust cutout.
The differences for a dual exhaust setup using 2 cutouts are noted.

TOOLS REQUIRED:

- 3/8" Drill Driver
- Socket Adapter for drill driver
- T-20 Torx bit
- 25' roll of 16 AWG or 18 AWG (Red)
- 25' roll of 16 AWG or 18 AWG (Black)
- Wire Cutters
- Wire Strippers
- Connection Crimper
- Needle nose pliers
- Large zip ties
- Small zip ties
- Heat gun
- 3/8" Socket Wrench
- 9/16" socket
- 9/16" combination wrench
- #2 Phillips head screwdriver
- X-acto blade
- Worklight
- Thin, sturdy piece of plastic (aka "trim stick")
- Pen
Not pictured: Dremel tool with cutting bit, 2-pin connectors, 3/8" heat shrink tubing.

On this particular vehicle, the Y-Pipe necessary for cutout installation has already been welded in place.
Y-pipes can be installed by your local muffler shop (welded) or at home (clamp-type connections). If your local muffler shop does weld them in place, TRIPLE-CHECK that the mounting flange is 'clocked' correctly (so that all bolts are accessible). This will really help with installation of your electric cutouts.

Test fit the electric cutout (aka EC) onto the Y-pipe:

Make sure that the wire and connections are clear of the exhaust port and other heat-producting elements. You should be able to adjust the EC position slightly for proper clearance.
Remember that you can 'flip' the EC to possibly get a better/cleaner fit under the truck.

With our EC mounted in it's correct position with finger-tight nuts and bolts, we can move on to the wiring.

After doing a test-fit, we found that the wiring that came with the EC kit was a little short for this installation, so we needed to add some length to it.
Plus, I don't just zip-tie stuff to frame rails and call it good.

Slide both pass. and driver seat all the way forward, and grab a buddy- the rear storage tray removal is 100x easier with 2 people.
We removed the rear storage tray behind the seats using the drill driver, socket adapter and T-20 Torx bit. There are (3) screws on the floor of the storage tray that need to come out.
The tray can then be wiggled out from behind the seats. Be careful not to scratch the B-pillar panels or flex the tray so much that it breaks.

*QUAD CAB OWNERS*: Please update this regarding behind your seats and the wiring under the cab carpet.

Once the rear storage tray is removed, we can begin routing the extension wires.


On this truck, the cutout is on the pass. side, so we're going to use the floor hole under the carpet to run our wires through.
You'll see a small white (or black) plug in the floor hole. Using your fingers, remove this by firmly lifting up on the edge and pulling it out. Don't use pliers; you'll shred it. (Dual EC installs will need to pull the drivers side plug as well)

With the plug removed, we can begin running the wires:


We run a little extra length and check for basic routing and any possible binding or rubbing issues.


As you can see, it's pretty much a clean shot straight down:


And here's what it looks like from underneath the truck:

(HINT: Put about 8" of heat shrink on the wires at this point. Snug it up to the access hole in the cab.)

Since we're going for a super-clean install, we're going to run the wires through the top of the outside of the bed support:

Getting the wires through the holes in the frame was a little tricky, even with skinny hands, but patience and determination paid off. Thankfully, the hole is straight through.

Originally, I wanted going to run the wires through the oblong hole on the inside bed support:

With the position of the connector on the EC, this would have placed the EC connection and wires directly on the toasty muffler.

I re-routed them down, next to the frame rail but inside the inside bed support:

They come out almost level with the top of the EC, providing enough clearance for the connector not to touch anything hot or be in a direct line with the exhaust when the EC is open.

With the wires protected by the bed supports and frame rail, they won't be as exposed to the elements. It makes for a slightly more difficult installation, but it's worth it in long run for the protection of the wires.

I wanted to use the same connectors that came with the EC, so I stopped by JEGS and picked up a pair of matching connectors:
http://www.jegs.com/webapp/wcs/stores/servlet/product_10001_10002_31462_-1
Part #121-8173
Price: $7.99 ea.
This gave us a same-connector "extension line" to the original. It really helped with installation and will help later on with maintenance and diagnosis.

The connectors were new to me, so I had to figure out how they went together.
THERE ARE NO INSTRUCTIONS FOR THESE CONNECTORS! (Shame on you, MSD).
Also, the largest gauge wire they can handle is 16 AWG.
Here's how to assemble the connectors:
- slide 'weatherstrip ring' onto wire.
- Strip wire 1/2"
- Attach pin
- Insert pin into connector housing
- Slide 'weatherstrip rings' along wires to main connector housing.
- Close the clip on the main housing.
Notes: Make sure that the flanges on the pin are 'out' enough to snap into place when they get inserted.
It's *much* easier to prep both wires with pins THEN insert them into the connector.
Double-check the male/female connections when putting the connectors on. The pins are also male/female specific.

The wires are trimmed to the correct length (with a tad extra for strain relief/bed movement) and stripped:

Heat shrink is also installed. I used about 6", enough to get the exposed wire covered and reach the edge of the bed support and into the first hole on the frame.

The weatherproof grommets are installed on each wire:

Then the pins, and finally the connector end.

Here's the new connector installed and attached to the EC:


Now we can fire up the heat gun and melt a little heat shrink! I did the section by the EC, then also the piece we had up by the port in the body floor:

OPTIONAL: Some folks love that wire loom stuff. There's enough room to use it if you'd like.
The other good part is that it can be added at any time.


We're done under the truck, let's go back to the cab....

I kinda liked how the plastic grommet folded slightly when we test fit it back into the hole in the floor.....but I just wasn't 100% with it.
I had an idea!
I grabbed the X-acto blade and cut approx. a 1/4" slit, length-ways, starting just inside the edge of the underside of the grommet:


This was MUCH better than before:


And the end result is more pro too:

Yeah. That'll work nicely.
(When we finished the wiring and snugged everything up, about 1" of the heat shrink from underneath came through the slit in the grommet. Looks, and works, great)

No one likes working with dozens of feet of tangled wire, so we mapped out the approximate run from the grommet to underneath the drivers seat (where our original wiring connection is)...and trimmed the wires.
Ahhhh...that's MUCH better.

Now we run the wire from the pass. side over to the drivers side, underneath the carpet:

The hole on the drivers side of the carpet is our mark for "the turn" to go towards the underside of the drivers seat. (Dual EC folks will have the wires from their 2nd EC coming out of that hole)
We didn't want the wires to 'pull straight' and run at a funny angle under the rear storage tray, so for alignments sake, we pulled them through that hole.
I used the drivers side hole grommet as a "right angle guide". I pulled the grommet 1/2 way out, and ran the wire along the outside edge of the grommet.
IMPORTANT! Loop the wire at the hole then run it BACK INTO THE HOLE. Otherwise you'll have a 6" section of exposed wire.

Here comes the fun part: Getting the wires past the S-shape from behind the seats to under the seat. The body has a dip in it that makes it difficult to run wires....though I really did try:


This is really a two person job: one guy feeds the wire from the back, as far down the dip as he can...while the 2nd guy reaches under the carpet under the drivers seat as far back toward the dip as he can. A little bit of wiggling, and you can make it happen.
WAIT!
Don't pull that first wire all the way through yet! We're going to use that 1st wire as our fish line! (good idea, Keith!) Tape your other line(s) to the first wire:


THEN pull the first wire through, slowly but firmly:

And all your wires will magically appear under the drivers seat carpet!
In that picture, you can also see the wire that remains on the back tray area in a loop.

While you hold the end by the rear grommet, your buddy can snug up the other line and take out the remaining slack:

I placed the wires on the inside of the big square chunk of wires under the door trim. It fits nicely in there.

Finally, you can bring your wires up through the bottom of the drivers side carpet. There's a slot that's pre-cut at the factory for your power seat wiring:

Hey- what's that gray cable?
We'll get to that in a minute....

On this truck, Keith decided he'd like the control switch on the panel directly in front of his left knee. On some trucks, this is where the switch for the power pedals is located. On this truck, it's wide open!

The panel has to come off so we can put the switch hole in it. Removing this panel is EASY.
- Your body trim kick panel should already be off. If not, it's held in by simple clips. A firm tug on the (2) by the A-pillar, and (4) on the floor and it will lift right out.

With your "trim stick" (aka plastic sticker scraper) remove the side cover plate:


There are (2) Phillips head screws that need to come out:

(He should be a hand model, eh? LOL)

The panel is clipped in so a firm grip and a solid tug downward and it will pop loose:

It has U-shaped hooks on the bottom edge, so pull the panel down towards the floor and it will come free.
If you have power pedals, you will need to disconnect them via the plug on the back of the panel.

HINT: Regular tape does NOT stick to the dash pieces. I had to upgrade from my normal masking tape to the big boy: duct tape.
I placed a strip across the face of the panel area where the switch is going to get mounted:


Then down to the shop we go. We're using the switch mounting bracket that the company provided as our template for the switch hole:


I marked the outside edges, and a top edge line. Then I measured to find the center of that section of the panel:

The hole itself is also marked.

While it's true that there are better Dremel bits for cutting plastic, I was feeling very Jeffrey Dahmer that night:



The basic hole is cut:


CAUTION - CAUTION - CAUTION!!!
DO NOT cut the hole too large. If anything, start small and work your way up.

The hole is leveled off, and cleaned up with the X-acto blade:

The plastic is easy to cut with a sharp blade. Take a little at a time and test fit as much as possible.

Back up at the truck, we have the original wiring run behind the dash in a temporary way so adjustments can be made. Here you can see the connection for the control switch being checked, and the remainder of the original wiring run over on the left, by the door sill:

We'll tuck everything away nicely in due time.

Here we check that we have connection clearance and length. We also checked the Open/Close direction of the switch to make sure it gets mounted in the right direction.
Note that the factory heat shrink that was over the connectors of the control switch had to be peeled back:

The switch wouldn't fit through the mounting hole otherwise (on ours or the original housing!).

Everything fits nice and tight (and clean), so we pop the switch into place on the panel:

The tab of masking tape marks our "OPEN" side of the switch.

Here's a shot from behind, after the heat shrink has been folded back into place:

Okay. Switch is in and hooked up (and looks good! LOL).

Slick, eh?


Okay, only 2 more wiring sections- In-Cab and Power.
Let's start off with the Power connection....
But first......REMOVE THE NEGATIVE BATTERY TERMINAL!!!!

Under the dash, on the drivers side of the firewall, you'll see a cable for your hood release. Follow that cable from the latch to the firewall. There is the grommet we'll be using to get our wires from under the dash into the engine bay:

DO NOT use pliers to pull the grommet out. You will shred it. Only use your fingers and a 1/2 pint of elbow grease.
TIP: Have your buddy push the grommet from the engine bay while you pull from under the dash.

When the grommet is out of the firewall, stretch it a bit and slide your power connection wires through the small hole in the rubber grommet, and then through the hole in the firewall, and into the engine bay.
DON'T re-install the grommet yet. We need the wire loose so we can set distances in the engine bay.

For the ground wire, you can pretty much attach it anywhere there's a ground wire on the truck. Fortunately, there's one right on the top inside edge of the quarter panel:

A 10mm socket will remove the nut.
As you can see, I added a ring connector and some heat shrink to the original ground wire connection. WAY more pro, and totally durable.

For the 12V connection, we went with one of my Access-A-Fuse fuses. #37 in the fuse box is listed as "SPARE", so we'll use that:


The Access-A-Fuse things are cool, but not very durable. After having two of them snap on me, We decided to run a direct line to the (+) terminal on the battery with a weatherproof 5A fuse holder in the middle. Works like a champ.

Check your connections and make sure the cables run cleanly in the engine bay. Zip-tie to other wire bunches if necessary.

Now we can go back to the cab and get rid of all of our slack!

Place the hood latch cable grommet back in front of the fire wall (but don't push it in yet), and pull the wire slack through the grommet.
Now you can push the grommet into place.

Run your extra wiring along the gigantic bundle of cables under the dash. For this installation, I matched the gray cable up with that huge wire cluster and zip tied it to the wire cluster:

Looks factory, no?

The control switch wiring is connected behind the dash:

You'll see an access hole in the frame of the dash that will allow the wiring to lead almost directly to the switch location. Very handy.

Now we can take up some of that slack....

The gray wire from the EC company runs just outside the edge of the dash, then down the edge of the door frame. You can tuck it behind the insulation if you like.
When you get down to the floor, you will need to loop the connection end UNDER the parking brake control cable:

Then run the gray wire along the inside of that square wire block that's along the floor.

When you get to the area under the drivers seat, map out how much cable you'll need and then tie off the remainder:

You can also shorten it if you like.
Slide the excess under the carpet and then under the drivers seat.

Pull your connection through the pre-cut hole in the carpet. Here it will meet with the extension you made from the EC:

Note that the extension wires are prepped and ready for the connector housing to be attached.

Here's the under-seat extension connection completed:


And here are both connections finally clipped together:

The final length on the extension wire after the slack was removed was approx. from the pre-cut hole in the carpet to the edge of the drivers seat.

We did the connection under the seat for a few different reasons:
- Ability to diagnose problems w/o tearing the rear cargo tray out to check a connector.
- Ability to adjust or add wiring without having to tear out the rear cargo tray.
- If there is a wiring problem, only one area needs to be dismantled (dash or rear cargo tray). Not both.
Under the seat is a nice access point that's semi-exposed.

Now we can hook the NEG. battery terminal back up and test out our system.
Unless your arms are REALLY long, you'll need a buddy.

We found that you should count to 5 when opening and closing the system. That's approximately how long you need to hold the switch for.

If the system checks out, we can put all of our panels back on.
Start with the rear cargo tray. Make sure both of the floor grommets are seated properly, and that your entension wires are clear of the screw holes.
The screws from the cargo tray will keep the wires on the top level of the cargo tray area and prevent them from sliding down toward the seats.

Re-install the (2) Phillips head screws for the switch panel:


Re-install the dash side cover panel. It just pushes back into place.

You can re-install the door sill trim. Check that all clips are fully seated. Healthy pushes and you should hear the click.

Double check the weather stripping edges and that they are seated correctly.

Last thing to do is finishing tightening the EC onto the cutout.
(You thought I forgot about that, didn't ya? )
Using the 9/16" combo wrench and 9/16" socket, tighten down all 3 nut/bolt connections on the EC.

Here's your final installation:


You're now all ready to open and close your exhaust with the push of a button!



©2007 Kevan J. Geier
All Rights Reserved