I am considering installing heavy duty, thicker battery cables. I see a few places on line that will custom make them, any size or length or ends. Commen sence tells me the thicker the cable the more power to the starter to help in the hot start problem. So.... I am considering new cables and a new high torgue starter. I just put new cables and a rebuilt starter, but feel it's just a matter of time before failure here with temps around 100 on a daily basis.
Will I fry anything?

 

Thick battery cables were only used with 6V .. 12V battery cables are much thinner.

12V introduced in 1956, 1928/55 are 6V

 

Thicker cables won't cause harm electrically. Mechanically, a larger wire may be harder to route and "might" put stress on the terminal but I doubt it'll be a problem.

The starter will only draw the current it needs. A bigger wire can't push more current into it. Because of this fact, there is a point of diminishing returns but without measuring the current draw and voltage drop of your particular truck, I couldn't tell you what it might be.

Google "how to measure starter voltage drop" or some variation for images and techniques for testing the voltage drop of your existing cables and solenoid. If you don't have a meter, the ultra cheap harbor freight one will work just fine here. I would be shy about using it on 120VAC though.

The general consensus is no more that 0.8 volts (800mV) with 0.3 volts (300mV) being preferred, total drop from battery post to starter terminal and no more than 0.1 (100mV) drop for any one connection.

And as NumberDummy points out, 6 volt systems needed larger cables due to the lower voltage.

Michael

 

Some additional thoughts.

Make sure the ground cables are up to snuff also. You need a ground between the engine and frame and frame or engine to cab. The solenoid also needs a good ground, usually provided by it's mounting bolts.

Michael

 

You can never oversize cables.. no worries there. Ideally the largest you practically want to run are 2/0 cables anything above that is just over kill on a 12V system. Actually 1/0 will cover 99% of installations.

Most factory cables in the era are #2

Your ground cable can be one size smaller than the positive.

If you want to make custom cables let us know and I walk you though the steps to make life time cables that will never ever need to be replaced.

Don't forget the battery terminals cheapo terminal are worse then under sizing the cable.

I always opt for Mil Spec Battery Terminals.

https://www.napaonline.com/en/p/PHI8619
https://www.napaonline.com/en/p/PHI8618

 

I was looking to have all three made up from 1\0 cable. That will include the positive, negative, and the selonoid to the starter.
The price for all 3 comes to 61.00 with free shipping and that's to my specs.

 

Ha at that price just get em made up. You'd be hard pressed to buy just the cable at that price.

Have them use eye lugs on all the ends and then use the Mil spec battery terminals.

 

In general, no harm with bigger cables... and cable size required for adequate performance depends on length of run.

Common parts store "heavy" cables are 4 gauge. Just or barely adequate for short runs. Make your own or buy 2 gauge or heavier will improve starter performance.

Also do not forget the charge or alternator side. OE charge wire was pretty light. If you have upgraded alternator, heavier charge wire is highly recommended. With common upgrades, 6 gauge is good and 8 gauge OK.

 

With new cables, should I be concerned that the selonoid is a week link in the system? I read all the time about there low quality in the aftermarket parts world.
I actually did some very simple investigating and I now am running 4 gauge cables from a discount autoparts store. 1\0 should be a big help

 

I had some 2/0 cables made for my truck, both battery cables and the starter cable. They made a huge difference. My old cables were toast (melted in spots and brittle from long hard starts) and I'm sure just new replacements of the same size would have been fine, but I wanted to make an improvement if I was going to go through the trouble of replacing them all anyway. I would also recommend replacing and/or adding new ground cables for your truck in general, block to body, body to frame, etc etc.

Also, check this thread out. https://www.ford-trucks.com/forums/1...ire-gauge.html

 

The solenoid should be the weak link in the system. Better to have it go up smoke then you cables. And Made in USA Starter relays are readily available. The issue is people do not want to pay Made in USA prices, then complain when their cheap China made crap fails.

As with many things in life you get what you pay for.

 

Thank you for this, i read everything and will definetly have bigger cables made. Last week i redid and added all new grounds with ground straps. Besides the factory grounds i also added new body, frame and engine grounds. Would you remember how long the selonoid to starter cable was and did you use straight or angled ends at the starter?
I think i have a good measurement, but courious how long you had that made.

 

I honestly don't remember how long they were. I took the cables off and took them with me and handed them over once cable size and terminals/lugs were selected and said make them the same length as these. All my terminals/lugs are straight. I'll probably get the ends redone at some point with different lugs and/or terminals to make it a little easier to connect a couple of them due to the fact that 2/0 cable doesn't bend as easily as the factory size does. Some 90 degree lugs might help me out, like connecting to the starter positive post and the negative connection from the battery to the exhaust stud. I think the one that had the sharpest bend was the positive from the battery to the solenoid, but I don't think a 90 would help there, it's basically a 180 degree turn. I recommend looking at your setup now and just visualizing all the cable runs and where each one will be routed and if there's a potential for any stress on them where a different lug might help. Also, consider the position of the lugs before they are crimped on or soldered. Mine are designed to be mounted with one side facing a certain way, so if they're crimped/soldered on without consideration of that you'll risk having to twist the cables in order to get the lug to lay flat against whatever you're bolting it to. I'll try to show an example of what I mean.






I seem to learn a lot in hindsight! Another thing I learned is that the lugs on my 2/0 cables are thicker than the oem lugs, so they take up more real estate on the solenoid post. I can't hook anything else up to my solenoid now, granted it does have three factory wires connected AND the battery positive, but that battery positive lug is THICK.

Have fun.

 

On another note , bigger cables work better for sound systems and winches

 

If you're having legit hot start issues, battery cables won't fix that. you've got a heat soak issue. Put a heat shield on the starter.