Ok, I finally bit the bullet and had an auxiliary fuel tank made like I wanted. none of the aftermarket ones had a 'real' toolbox on them, and none of them sat on the bed rails.

I now have a full size toolbox, and a 60 gal aux tank as well.

The issue is, the sender for the aux tank is the wrong resistance range to work with the stock dash gage (but it is supposed to). I am gonna try and get in touch with the manufacturer tomorrow, but in case that fails, anyone know of a sending unit that will work with a 97 dash gage (97 ohms empty, 32.5 ohms 1/2, 9 ohms full) ?

I supposed I could use a 90-0 ohm gm sender, and wire in a resistor to get he correct ohm range if needed.


Here's the tank by itself



Here's the whole deal, toolbox and tank



Once I get this level sender worked out, I hope to get a fuel door, frame, and fill neck from a wrecked truck, and put it in the side of the bed, so I can fill both tanks from the outside, having one fill door for each tank.

I hate the thought of diesel fuel in the bed of the truck from spillage.

 

An easy way is to just gravity feed into the main from the aux. When the dash gauage starts to move you know the aux is empty.

 

If you wanted a "on the rail" box... that is the way to go... I wouldn't want 500lbs of fuel, plus the weight of the tools and stuff in the box, beaten the bed rails to death.
The way you did it distributes the weight to the bed floor instead... good job!

Oilguy

 

If you decide on the gravity feed from the aux to the main tank, I
would also add a cutoff valve "at" the fuel line outlet on the aux tank.
You could run with it open all the time but also have the option
of opening the aux tank valve when the main tank gets towards empty.
I think the latter would be safer.

I filled both my tanks one day and forgot to close my cutoff valve "AND" put the cap back on the filler neck of the main tank. I went into the store to pay up and when I got back to the truck fuel was dribbling out the filler neck on to the asphalt. I guess about a pint or so ran out which is bad but it wasn't catastrophic. had I decided to eat lunch or just goof off for an hour or so.......

My cousin has the cutoff valve but under his truck. he runs with open all the
time because he doesn't want to have to reach waaaay under his truck to
open and close it. It finally caught up with him with some kind of fuel line
break between his aux tank and factory tank while he was away from his truck for awhile. And to make it worser, he has a 100 gal tank. All didn't leak out but was more than a pint. I wasn't there but he said it wasn't pretty.

Your filler cap will be behind a locked door so you needn't worry about someone coming along and removing the cap and letting the fuel run out.
I have a hauler bed with the filler cap exposed to the whole wide world so
murphy's law could easily rare up,,,,ie, a kid could walk by and remove the cap.
Although I use a locking fuel cap, I'm still concerned about it. The fines for a serious fuel spill are very high $$s I here.
A conveniently located $5 cutoff valve is cheap insurance.
You can get higher priced electric and manually controlled valves that you can
operate from inside your truck.

I got longwinded I know,, and I think you probably know everything I've written here so just a reminder of the high dollar fines nowdays on the enviromental stuff not to mention the envoromental damage and embarrasment.

But a real, real nice tank/box you have. I'm jealous. I wish I had an
answer for the gauge/sender thing but ohms and things like that aint my
cupatea.

 

I have one of KSH's combo boxes and do find that the gage works good but does read lower than what the aux tank really has in it. This is on a 07 with the 6.7.
Have you called and talked with them (a tech) to discuss the sending unit issure with them??

 

Yes, I have called and talked to Brian more than once. While the tank looks awesome, I am not exactly pleased with the customer service. When I pay as much as I did for the tank and the installation kit, I expect it to work as advertised, and since it was a custom made tank, it should have been made to the detailed drawings I provided.

To begin with:

1) They did not ship the install kit with the tank as they told me they would, which cost me a week because when they realized it wasn't shipped, they sent it normal ups ground vice overnight (afterall, it was their mistake), and when they did ship it, they sent it sig required, which meant had I not had that day off work for other reasons, I'd have had to wait another 3 days to get it.

2) The tank was not made according to my drawings, and it cost me $ 75 locally to fix it (fill neck was at an angle vice 90 deg to tank top which made it impossible to fill).

3) The sending unit will not work with stock gage as it is supposed to. I questioned them to make sure the sender would be calibrated to the tank and the factory gage. I was assured it would be. Well, the sender they sent read 3/8 tank when the float was all the way up. They claim I am the only person to ever have this problem, but their sender was a 240 ohm empty - 33 ohm full generic unit, and my factory dodge gage requires 97 ohms empty and 9 ohms full, (with 32 ohms being 1/2 tank) to read correctly.

4) The instructions that came with the install kit are very confusing, because there are a lot of mistakes and inconsistencies, most notably the wrong wire colors are listed for splicing into the factory harness and the wires they provided were referenced by end connection, and the actusal connections provided did not match the instruction sheet.


I have lost almost 2 weeks over this, and when I asked them to send the replacement sender (which was obviously their mistake) overnight, they initially refused. I was about to get less nice about it when Brian called me and said he was going to overnight me the correct sender (the closest he could get that is). I had to go fill up my stock tank and measure the resistance on the sending unit to prove to him that my factory service manual was right and that a sending unit that reads 33 ohms full would not give the correct tank reading on the dash gage.

The only reason I even ordered their install kit was because I wanted a remote gage readout, and since theirs used the factory gage, that meant one less gage to clutter up my dash with.


As I said, the tank is awesome, but the customer service is less than average as far as I am concerned. This isn't meant to bash anyone, as I am not really mad at them, but to simply and honestly relate the problems experienced. Mistakes happen, but when a company makes a mistake, they should own up to it and fix it ASAP. but when that same company makes more than 1 mistake on the same order that affects the customer as well as the quality of their product, the company should jump thru hoops to make it right, and I don't feel they did so.

 

update:

They did send the replacement sender overnite...on firday so it still came monday.

It will work close enough, but since it is a chevy sending unti, it isn't exact. the full works, and the empty works, but the low fuel warning light comes on at 1/4 tank.

They did 'resolve' the problem, but it took a lot of prodding to get them to fix their mistake.