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Discussion Starter #1 (Edited)
The wife and I are planning a road trip in the near future and I knew the 36 gallon on-board tank was going to impede progress while pulling our trailer and trying to make good time, so I went ahead and purchased the 50-gallon Titan Travel Trekker on Amazon. The instructions are very generic so I was on my own in terms of mounting the pump, switch, wiring, and plumbing. I think my total install time was about 10-12 hours, a good bit of which was just figuring out how to do things, rather than actually doing them. Hopefully this write-up saves some folks some time (shout out to @hdrolling).

Note: please read the factory instructions and my complete write-up in their entirety before beginning installation. And be aware that while I like to think that I know what I'm doing, any deviations from the factory's instructions are your responsibility alone.

Note that the tank install instructions are designed for an essentially "permanent" installation. I wanted modularity so I did some things that may not be optimal if you have no intention of removing the tank on any sort of regular basis. In particular, I used quick disconnect fuel and electrical fittings (purchased separately from the tank). Additionally, I deviated from the install instructions by not drilling holes in the bed for the fuel and electrical lines, since our beds have capped holes in the upper part of the bed that can be used instead. I also deviated from the instructions by not grounding the tank to the brackets; more on that later.

Stuff I used in addition to the hardware provided:

Wire loom: https://www.amazon.com/gp/product/B07DW17QJZ/ref=oh_aui_detailpage_o08_s00?ie=UTF8&psc=1
3/8" fuel hose: https://www.amazon.com/gp/product/B0058I2552/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1
5/16" fuel hose: https://www.amazon.com/gp/product/B008VO5YP8/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1
Hose clamps: https://www.amazon.com/gp/product/B001HWGMBG/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1
12V all-weather quick connectors: https://www.amazon.com/gp/product/B01A6LTK44/ref=oh_aui_detailpage_o09_s00?ie=UTF8&psc=1
6AN Male Flare to 5/16 Hose Barb Fitting: https://www.amazon.com/gp/product/B07DXP22NT/ref=oh_aui_detailpage_o00_s01?ie=UTF8&psc=1
6AN Male Flare to 3/8 Hose Barb Fitting: https://www.amazon.com/gp/product/B07DXP4JMR/ref=oh_aui_detailpage_o00_s01?ie=UTF8&psc=1
6AN Female Flare to 5/16 Hose Barb Fitting: https://www.amazon.com/gp/product/B07CYY92KG/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
6AN Female Flare to 3/8 Hose Barb Fitting: https://www.amazon.com/gp/product/B07DLQGYQP/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
WD-40 silicone spray: https://www.amazon.com/WD-40-Specialist-Resistant-Lubricant-STRAW-SPRAYS/dp/B00631GRPW/ref=sr_1_1_sspa?ie=UTF8&qid=1541476911&sr=8-1-spons&keywords=wd40+silicone&psc=1

You'll also need a 10A fuse and holder, as well as additional butt connectors and ring terminals of various sizes. You will also want a set of truck ramps to make the wiring and plumbing easier. I use these and they are fine: https://www.amazon.com/gp/product/B0117EETEK/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

The first step is to haul the tank up into the bed and situate it. It should fit easily under any bed cover. The instructions say to center it but I offset it to the driver side for two reasons. The first is that it makes the fill neck closer to the bed rail, which facilitates filling. The second is that I wanted the brackets to be set such that the heads of the upward-facing carriage bolts would be in the recessed grooves in the bed. I recommend that you attach the fuel lines to the barbed fittings on the fuel intake and return lines so you can figure out how much clearance you need off the front of the bed. You have a good amount of freedom in how far you offset from the front of the bed to accommodate different style bed covers and other accessories that may cause interference.



In my short bed truck, I set the tank such that the seam down the middle was exactly 9" from the front of the bed (that's from the lip along the top that sticks about an inch or two out from the lower part of the front of the bed). I believe it says to use a 7/16" bit, but I think I used a 3/8" and it was fine. However, installation hardware may vary somewhat based on purchase date.



With the tank set in the bed where you want it, go ahead and mark the holes for the brackets. Some may find this unsightly, but I just outlined the edge of the brackets with a black sharpie. Now you can easily mark your holes.





Next, remove the small heat shield from the passenger side of the underside of the bed.



This part is important: You will be drilling directly over the fuel tank (and fill tube) and you do not want to risk going through the top of it. To that end, I recommend the following precautions: 1) use a backstop (a block of wood, for instance) placed between the on-board tank and the bed to block the drill bit when it punches through, and 2) use a 4x4 or something as an additional backstop for the drill itself to limit how far it can go through the bed.





I recommend you seal the bare metal edges with paint or caulk (I used black silicone) to prevent corrosion. Here's what it looked like when I finished the brackets.





Now go ahead and reinstall the heat shield you removed earlier. You shouldn't need to work in this area again.

I mentioned above that I deviated from the install instructions by not grounding the tank to the brackets. There are two reasons for this. The first is that if you do this correctly, the brackets themselves should not be grounded , or at best, have only a weak ground. This is because there will be some barrier between the carriage bolts and the bare metal (the paint or silicone I used); these are not sheet-metal screws that have a direct interface with the metal. The second is that I wanted the tank to be modular. I wound up just bonding the two ground wires (the one on the fitting that is supposed to be grounded to the bracket and the one on the sending unit) together and connecting them to a 12V quick connect; more on that later.

The next thing I recommend you do is to run the fuel lines from the tank to the tentative pump location. I recommend that you install the fuel quick-connects (if you bought them) at this time as well, so you'll be working with the actual length of available hose. However, before you put on the quick-connects, push the grommets onto the hoses so once everything is plumbed you can seat (and optionally, caulk) the grommets without any disassembly or drama. When you install the quick-connects, I recommend you reverse the gendering on the fuel and return lines so that when you remove the tank you can completely seal both the tank and your truck's fuel system (see second pic below). For instance, the truck side of the fuel line should be male, while the truck side of the vent line is female. This also prevents you from mixing up the fuel and vent lines during tank installation.



Truck and tank sealed/isolated and prepared for the tank to be removed:



Grommets and loom plumbed through the hole on the upper driver side hole in the front of the bed (with black silicone to prevent them from slipping):



Now, to mount/plumb the pump. The best place I found for the pump was a pre-existing bolt in the bed that you can easily remove and then run the bolt through one of the holes in the pump's mounting bracket. You may have to drill this bracket out very slightly for it to fit, but it's otherwise a great place for mounting (I only secured one side of the pump; with a bolt this size holding it, I think it's fine). You can also use a large ring terminal on the grounding wire to ground the pump to this bolt.

If you're smart and ran the loom through the hole like I mentioned above, you'll run a grounding wire for the tank down through the loom to this same bolt and ground it there as well. That will allow you to completely avoid drilling grounding screws into your bed (in my pictures you'll see an unsightly grounding screw near where I ran the fuel lines and loom through the hole; didn't think of this until after the fact).

The image below shows my configuration and it works fine. However, I recommend that you try to install the double-Y barbed fitting into the vent line at a location where the vent line is more steeply inclined because it will prevent a "fuel trap." Because the vent line is relatively flat where I installed the fitting, the fuel spraying into the fitting from the pump actually blocks the vent line to some extent, which forces the pump to fight the static pressure of the fuel associated with its height above the on-board tank. The effect is extremely minor and is only perceptible when you open the on-board fuel cap immediately after (or during) auxiliary pump operation, or try to add fuel to the on-board tank immediately after running the auxiliary pump. It's not nearly significant enough for me to re-do the installation to avoid it, but if I was doing it again from scratch and could do something to minimize it, I would. What you absolutely do not want is for the fuel line from the auxiliary pump to be higher than the vent line back to the auxiliary tank. That will cause all sorts of issues.



Here is the section I cut out of the truck's vent line:



Next step is the wiring. Following @1Blue78's advice, I tied into the "retained accessory power" by crimping a female flat blade connector (14 ga, I believe) onto the power wire for the control unit. I fused the connection with a 10A fuse and grounded it using one of the dashboard bolts, as shown below.



You can mount the control unit here with the provided velcro tape. You can see in the picture below how I ran the blue and purple wires through one of the holes.



Now comes the annoying part: getting the wires out of the cab. Again following 1Blue78's advice, I ran them through the grommet used to pass the parking brake cable through the floor. But first, I cut the tips of the wires diagonally to make them pointier, which helps in ramming them through the rubber boot/grommet.



You will need to remove the trim pieces around the floor (including, possibly, the door sill plate -- try not to crack it like I did) in order to access it. It is held in by two bolts; remove them. Spray the parking brake cable and the tips of the wires with silicone, then pull the grommet back up the cable a bit. Now stick the wires into the top of the grommet and ram them through. You may want to just hold them against the cable and slide the grommet up until you can grab them on the other side.



Now go under the truck with your loom and ram the end of it up through the hole through which the parking brake cable passes. Zip-tie the loom to the parking brake cable and pass the wires through the loom out of the cab.



Re-seat the grommet and reinstall the bolts, carpet, and trim. Secure the wires out of the way, optionally covering them with loom (I didn't but it can't hurt).









The rest is easy. Route the wires along the frame rail back to the pump. Conveniently, there were some plastic hangers already installed that I was able to use to hold my loom/wires which gives it a very OEM appearance.



Make sure you route your wires behind the cab-frame mounts, otherwise you'll feel dumb like I did and have to re-do it. Here's what you don't want:



I just hit the image limit. I will continue the write-up in the next post. If you happen to be seeing this before I've posted the rest of it, please do not reply until the entire write-up is posted; this will help continuity. Thanks.
 

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Discussion Starter #2 (Edited)
And here's what you do want:



At some point, you'll have to split your blue (pump) and purple (sending unit / level meter) wires apart into two separate pieces of loom. Cover all gaps in the loom with electrical tape.





Connect the blue wire to the pump using a heat-shrink butt connector (and make sure you heat-shrink them). Cover the wire with loom and secure it out of the way.





The completed wiring along the frame rail should look something like this. Note my use of zip-ties after the cable hangers had stopped.



Now go back up into the bed and run a piece of purple wire down through the loom that you already ran through the hole in the bed. Connect the female side of one of the 12V quick-connects to this wire along with the grounding wire that runs to the bolt where the pump is mounted (this grounding wire is instead shown grounded to the truck bed in my picture; you can avoid this ugliness by following my instructions above for re-using the ground at the pump for the sending unit as well). [See "update" below; I went back and actually rewired the sending unit this way.] Connect the other end of the wire to the purple wire that came from the control unit in the cab using a heat shrink butt connector. Cover all wires with loom, and any gaps in the loom with electrical tape.



Now bond the grounds from the tank fitting and the level meter together, and connect this consolidated ground as well as the +12V side of the level meter to a male 12V quick connector.



And that's about it, folks. Secure the tank with the brackets according to the instructions, connect the fuel and electrical quick-connects, and you're all set. Good luck and let me know if you have any questions.

Update: I got so annoyed at the thought that I could have re-used the ground at the pump for the sending unit as well that this morning I went out and implemented this design. Here are some pics.



 

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Discussion Starter #4
This is going to come in handy, thank you!
No problem. I got so pissed last night when I realized how I could/should have wired the ground for the sending unit that this morning I got up and actually did it. I edited the second post to show how it looks now.
 

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No problem. I got so pissed last night when I realized how I could/should have wired the ground for the sending unit that this morning I got up and actually did it. I edited the second post to show how it looks now.
You did a great job and a great write up, I'm going to tackle rear air bags first but this should be happening in a few months.
 

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Discussion Starter #6
You did a great job and a great write up, I'm going to tackle rear air bags first but this should be happening in a few months.
Sounds good. Post a write-up for your airbags if/when you have the time. I just discovered that the floor is rotting in one of the slideouts of our TT (and unfortunately it's the one with the stove, fridge, etc.) so I think this road trip may be its last hurrah before we upgrade to a fifth wheel. I'll probably need air bags (and possibly 19.5s with 16-ply tires) to handle the pin weight since we will likely go for a large toy hauler.
 

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Sounds good. Post a write-up for your airbags if/when you have the time. I just discovered that the floor is rotting in one of the slideouts of our TT (and unfortunately it's the one with the stove, fridge, etc.) so I think this road trip may be its last hurrah before we upgrade to a fifth wheel. I'll probably need air bags (and possibly 19.5s with 16-ply tires) to handle the pin weight since we will likely go for a large toy hauler.
There is always something with these campers, I never knew how much of a money pit it was going to be. But the kids love it and ask to go camping all the time so I just keep repairing.

The toy haulers are nice, lots of extra sleeping space.
 

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Great write up! I have a 17 that I installed my dually depot 115 gallon auxiliary tank that I had in my 07. The auto fill module had gone bad, but still gave me my fuel level, so I'm still using that for the gauge part. I bought the killer neck piece for the 17 and just wired in a stand alone switch. Will post a picture later.
 
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