Yep! Hit the nail on the head!

 

Unfortunately, the previous owners did not take as good of care of the truck as I do. The main positive cable going to the starter is chewed through in the center by a rat. It didn't damage much of the actual copper but it was shorting out on different parts of the truck when bouncing around. Of course for now it is taped up so that it will not ground out but it needs to be replaced and if I'm going to replace the one cable, I might as well replace all the 21-year-old / 420,000 mi old cables.

I have checked out the military grade battery clamps and decided that was what I was going with. Lucky for me a kind FTE'r is it going to loan me his crimper when he gets done with it so that I may use it on my job as well! With my mild OCD, you can believe I will make sure everything looks tidy!

 

That would be the confusing since he said from battery to chassis which is still a large gauge cable from the factory, battery to body is a smaller wire.
Overkill is under rated. Like I said for mine, I used 3/0 for all main power and ground then added 2/0 from the engine to passenger frame and 2/0 for passenger body to frame. I used one of those woven straps( I think 4 gauge equivalent) from a starter mounting bolt to the frame. Still have to add some wiring from the alternator to the drivers side battery.

 

as I had said, I miss worded what I meant. The only 6 gauge cables I will use are the battery to body grounds and maybe the block to chassis ground (not sure). Not sure why I wrote battery to chassis. Everything else is 2/0. I could be wrong but I do not believe that this truck has a direct battery to chassis ground from the factory anyway. It might be indirectly connected one way or another through the block ground but, there is not a cable running from either of my batteries directly to the frame. I will be adding one or 2 though.

I hope this cleared up the confusion.

 

You are correct. The factory cables have a relatively small cable coming off the passenger side battery to block negative cable that goes to the frame. This smaller cable sprouts from the passenger side block attachment point. This is the only factory battery to frame connection.

 

Why?

 

125°C × 9/5+32 = 257°F

You'll notice that many if not most of the OEM Ford split convoluted wire loom (with Green stripe) is wrapped in tape.

I do the same thing with any wiring harnesses I add or modify. Sprial wrap the split convoluted wire loom in tape.

Hence, I don't worry about what color the split convoluted wire loom is. I only worry about it's construction... seeking thermally rated nylon instead of cheap plastic. If the loom has a stripe, then it is rated. No stripe, then it probably isn't.

To get the color red, I wrap the loom in red tape.

Just like regulations wrap us all up.

 

Y2K, what kind of tape are you using? I'm assuming that it's not standard (cheap), parts store PVC electrical tape. That stuff turns gummy.

I've been using Tesa brand of tape. I've got both the "interior tape" as well as the under hood, higher temperature tape. Both Tesa tapes are cloth backed (flat black) and not smooth and semi-gloss like yours. I'd like some high quality, high temp, smooth tape to re-wrap some of my electrical wires and connections under the hood of my Fox Body Mustang coupe project. I've got a Holley Dominator computer to run the engine and Holley used a smooth, semi-gloss black tape to wrap their covering over the wires. I'd like something like that but i haven't been able to find it.

 

Maybe Scotch Super 35? I'm curious too.

I've been using Super 33+ on my electrical stuff for years, but I've only seen it in black. This thread made me go look and that's because it is only available in black. Looks like Super 35 might be the red equivalent though. Might have to get some for future use.

 

For black, I use 3M Scotch Super 88. (220°F continuous temperature rating).

I find Super 88 to be a lot better than Super 33+ (176°F temperature rating)

For red, this is a case where you might do as I suggest, but not as I do.

3M doesn't offer Scotch Super 88 in red, so I have used 3M Scotch 35 instead. (I'm a poet and didn't know it but my feet show it... as they are Longfellows) (176°F temperature rating)

Being far better organized in my much younger days then nowadays, I bought a few rolls of every color that 3M makes in Scotch 35 many years ago (even brown, and lavendar, and green, etc) and while I've depleted most of that stockpile over the years, I have a few rolls remaining which I will continue to use until my supply is fully exhausted, like I am. Then like you, I might be looking for a higher rated red, unless I'm dead.

Keep in mind, if the concern is heat from an overloaded wire, there is still the higher rated wire insulation (if using SXL, or cross linked wire jacketing), and the higher rated, flame retardant split wire loom (if using striped spit loom)... to burn through before any flame or wire related heat ever reaches the red color coding tape.

If externally sourced heat is the real concern, you can overwrap the wire harness with aluminum coated fiberglass tape, as I have done in the photo below, where a cable is routed past and proximal to the exhaust manifold.

 

I just had to go verify this on the 3M website, but all three of those are rated at 221°F.

The the 33+ and 88 have a lower minimum working temp (0°F) than the 35 (32°F).

There are some other small variations, but probably the biggest difference between the three is that the 35 is available in colors, and the 88 is flame retardant.


I'd also use similar insulation if running near a high temperature point. Either the tape like you used or sleeves.

 

Because........... IDK

I figured it would be beneficial but in all reality all I really need are the block to chassis grounds. I know I'm going to have extra cable because I'm buying it in bulk. I will probably just save it for another project though and stick with block to chassis grounds. Not really sure what was going through my head to be honest

 

Excellent answer. Your honesty that is. Not knowing.

This type of instrospection and evaluation does anyone good stead... because rather than follow along what everyone seems to be doing, one can instead stop and consider WHY it is being done. And without being able to answer why, the next logical question returns to IF it should be done.

Since we know that the highest amperage electrical loads served by the batteries alone is the starter, and next the glow plugs, which are both grounded through the engine block itself... what need is there for big fat grounding wires to the frame?

Automotive electrical engineers design grounding zones within a vehicle. Ford calls them zones. GM calls them clean grounds and dirty grounds. Issues related to electrical noise and signal integrity interplay with grounds.

That is why we have an issue with the intermediate windshield wiper setting interferring with the hall effect camshaft position sensor... the sharing of a ground point on the firewall.

We know that electicity is often compared to water, which flows following the path of least resistance.

So let's suppose you keep your original ground lead from the battery to the block. It's old, maybe a bit wonky, but you leave it there, and focus on adding your new postitive cables.

You have some cable length left over, so you figure while you're at it, why not add some thickazz wires from the block to the frame, and from the frame to the battery to make a nice good resistance free ground path.

Over a period of time, the long standing corrosion that wicked into your original battery to block ground wire built up an increasing amount of resistance.

Like water, electricity flows through the path of least resistance, so now all the heavy starting current begins flowing through your battery to frame, and frame to block cables that you created and added after the fact of vehicle manufacture.

The body is grounded to frame, and the PCM is grounded to the body.

So now, the PCM could potentially be in the ground loop of the starting current.

There is a likely a REASON why Ford uses a smaller ground wire (that @FordTruckNoob described earlier) to ground the frame, than Ford uses to ground the engine block.

It is the engine block that grounds the highest electrical loads, so if a smaller wire is used to ground the frame, that makes for a path of higher resistance, which disincentivizes starting current from flowing through the frame, as the engine block, and the fatter wires from the battery directly to the engine block, offers the path of least resistance.

 

I had what they call an 'aha' moment while reading this post. I can't show enough gratitude for you taking the time to write all of this to teach me. I truly appreciate you!

 

Here's what I found for flame retardant nylon wire loom.
it was difficult to find a website that actually sold it with the stripe on it. Does it look good and trustworthy to you guys?

https://wiringproducts.com/products/...dant-wire-loom