Battery Cable question

[CrazyTalkCustom]

So my starter recently started acting up. not engaging, etc.... So i'm replacing it. while i have it out I want to repalce the battery cables with some 2/0 mainly because it will be alot better than stock but also cause my cables are really old and i aid any starter problems to the cables too.

I searched and searched trying to find an answer to my question but I couldn't.

I'm going to run a new heavier wire from the pass battery to my fuse block on the firewall but am not sure what to do about the fuseable link. Curious as to what you guys that made new battery cables did?

Thanks,
Nic

[racer55]

Haven't heard of anyone having trouble with that particular cable.

There is an aftermarket source of cables sometimes available on ebay,but the vendor is not a site sponsor so I won't post the contact info.

[57diesel]

Unless you have added a ton of electrical accessories I would just re use the original cable and link going to the fuse box. I have not read about failures there either. Sometimes I read about failures on the alternator one especially with upgraded alternators.

[bigblazer]

I did exacty what your talking about.the fusible link runs down by the starter for absolutely no reason why run a wire almost three feet longer than it needs to be and run it down where all the crap can get on it. My power windows and blower motor really thanked me for it.

[JMJNet]

The most important cables are the pos to pos battery terminal, battery to starter and battery to alternator.

The one to the fuse box is important but not as critical and hardly failed.
I have replaced mine with a straight 2 gauge on that one and never have problem.

[VanBoy]

In this case, bigger is better. I ran across the seller mentioned, nice looking cables. But for the price, I think I can put them together myself for cheaper (I have one of those HD terminal clamps that pound them).

My Ford IDI's and PS all use 00 cable from the looks of it. Not sure why GM went with what they did. Just about all the cables I use in my tractors are 00 welding cable. Nice and flexible.

[Steve83]

The terminals are FAR more important than the cables. My truck still has stock cables, and everything works fine because I keep the terminals tight & VERY clean.

If you increase the size of the cable that's protected by a fusible link, you CAN also increase the fusible link size (assuming a larger one is available), but there's no reason to unless you're ALSO increasing the load (current draw) on that cable. The standard for fusible link wire is that it's 4 gauge numbers smaller (higher) than the wire it protects. So if you install 00 cables, you CAN install a 3ga fusible link. Read these captions:

. .

[Missouri boy]

I picked up 2ga fine stranded wielder wire and converted to top post batteries. Its enough to spin the motor like a top when you hit the key.

[VanBoy]

Yes, the connections are important. If they are corroded or loose, it doesn't mean squat if you you have gold wire as the cables.

But wire size does also play a roll. On a Ford gas truck w/ 361-V8, I changed the positive cable from the battery to starter relay. What it had was a 4 gauge and I bought a 2 as replacement. The relay to starter, I kept the same...but just that little size change there, I could hear it spin MUCH faster.

I'm not an engineer (let alone electrical engineer). I would guess, that they make the system "just adequate" enough to spin the engine over and start when "new" and all is pristine. But get a few years (or a few decades), add some corrosion, wear on the engine, the system may not be quite enough.... And then add the fact it is a diesel......

The cable that connects the two batteries, that should be big enough to transmit the amps to the other battery. Somewhere, there is a chart that shows the size the cable should be for the amps to transmit vs the distance.

Here is another way to look at it.....people will crank over their engine longer then they should to try to start (for one reason or another). Human nature. If this extended cranking time is enough to heat up the cables, 1 you know you've cranked too long, 2- the cables are really transmitting amps (and maybe should be bigger)..... I've had to crank my 7.3L IDI for some extended time and even those 00 cable can get warm. Just think when it's a smaller sized cable......

[Steve83]

You're assuming that the starter for a 6.5 pulls as much current as that for a 7.5, which isn't NECESSARILY true. Obviously, wire size matters, but the stock wires are big enough. The reason they don't work as well as when new is the terminals; not the wire.

361 isn't a Ford engine size; 351 is a 5.8L, and it used the same battery-to-relay cable as the 4.9L, 5.0L, & 7.5L. From '92-96, their starters all draw a nominal 140-200A on a new engine, but it can range from 60-800A depending on the actual load and the factory wire is built to handle that. As an engine ages, it takes LESS current to spin it (lower compression, looser bearings).

The charts showing current capacity for a length of wire gauge vary widely based on the author's chosen wire installation (free air, insulated, against a panel, in a bundle), chosen acceptable temperature rise, and chosen duration of that current draw (1sec, 1hr...).