I noticed that between my stereo and the truck as a whole, the positive terminal on the battery had the equivalent of 3 4ga wires coming off, while the negative terminal had *maybe* an 8ga ground strap for each battery (they look a lot more like 10 or really thinly insulated 8)

Since we know that electricity flows from negative to positive, it might be fair to assume that this setup is less than ideal.

In terms of plumbing, let’s imagine for a second you have two showers, 3 toilets and a washing machine. The water supply to your house is an average McDonald’s drink straw. The water flowing through that straw is required to keep those showers running at a constant pressure regardless of how many times the toilets flush or how often the washer is running.

To make matters worse, alternators put out anything but clean steady voltage and the batteries act as a sort of buffer. If the batteries don’t have a solid connection, the voltage is constantly fluctuating. Back to electrical terms, try keeping the constant input voltage of a sensor steady when the input to the voltage regulator is anything but.

In short, I installed a bigger pipe.

I put a 4ga wire from each battery negative to negative and an additional 4ga wire from driver side negative to frame. I was going to run an 8ga on the less used passenger battery but today’s road test proved good enough.

Changes:
The idle seems smoother and the exhaust note is quite a bit more beefy sounding. Oddly enough there was a change in the smell as well. This might be because the lift pump was having voltage issues and wasn’t giving the VP44 the fuel it wanted, or perhaps the computer was having a hard time giving the engine timing instructions.

The throttle was much more responsive and the turbo was building pressure much faster than normal (several hundred RPM earlier and ramping up much quicker)

I tried for an hour to force it to go through a lock/unlock cycle. When the truck went into lock up at ~43mph, rather than falling flat on its face, it continued to pull. When I finally found a hill steep enough that it would pull, it downshifted. This is entirely new behavior.

My headlights are brighter, but just slightly.

I have a feeling my MPG has gone up significantly judging by today’s driving. I will say for sure after 3 tanks (next week by my old MPG standards of 12 AT MOST MPG)

I’ll also post pics and perhaps even build a couple of kits to sell since I have quite a bit of the materials for the project sitting around.

Before I get too far ahead of myself, I’d like to put another 800 miles on this set up just to make sure I’m set. So far though, I’m highly optimistic about the results.


Off to sleep, its roofing in the morning... thank god sun rise isnt till after 7 these days

 

How about some pictures? What kind of terminals did you use? Did you replace the existing ground wire? It's hard to believe that this would cause so much improvement but I know these trucks are finicky and anything is possible. Shouldn't cost very much to try. Thanks for the input.

 

I'll snap some pics when it isn’t busy raining/snowing/whatever.

My fuel mileage before the ground mod was right around 10.3mpg. My first two tanks after were 13.8MPG and 14.2MPG! Quite a bit of the first tank was spent driving around like an idiot trying to get the transmission to act up, so I am more inclined to believe the 14.2 as the “right” figure.

Also, I’m pleased to note that my fuel pressure at idle has gone from 4psi to 10psi. My torque converter lock/unlock has completely disappeared.

For something like $20 in parts I’ve gained a whole new truck. I’m not sure if this will work for everyone, but I’m positive that in my case, my electrical system was entirely messed up and this was the answer.

According to my calculations, I gained over 130 miles per tank. This is huge to start with, but let my compound this by saying that I’ve already burned over 3000 gallons of fuel this year. With my improved mileage, I would have only used around 2200! Even with fuel prices where they are right now, that would be a savings of $2120, however, fuel prices were an average of $3/gallon for a vast majority of that time which would save me $2400. That’s $200 a month!

Basically I’m just absolutely giddy.

At some point I’d like to add one more from the engine to chassis. It can’t hurt, and in two tanks, the first two wires have already paid for themselves twice with over $30 in fuel savings per tank.

 

I look forward to the pictures. I think this is worth doing even though I am not having any problems right now. I need to have something to work on or my truck will feel neglected. My other projects include replacing the intercooler boots and hoses. I looked at the lower intercooler boot and it was very soft - about like an innertube - so I think it is about time. I think I'll go with Pier"S boots and hoses.