I'm looking at relocating the control pack for my winch to inside the engine compartment, most likely to the rear of the fuse box or to the RHS firewall on a bracket I will fabricate (more on that later if all goes right). I'd appreciate some feedback about power cabling ideas. I really hope Tom Rowe will weigh in. (Where are you antichrist?)

To relocate the box I'd need to use cables longer than the 18" cables that came installed in it (A, F1, F2). I measured today and it looks like the new cables would need to each be 6 ft long. I'd most likely buy professionally made cables with professionally crimped ring terminals at each end.

The power cable running from the battery to the control pack is 6 ft long. It could be shortened in this installation, probably to about 4 ft.

I'm not an engineer but I tried to use an online voltage drop calculator ... but I don't know how to interpret the results.

Voltage Drop Calculator

I guessed that I should use the calculator for the full length of the cables from the battery through the solenoids and across the bus bars. I have no idea how to factor in the solenoids and bus bars but those factors will be constant so I ignored them.

A WARN table I found online showed max draw of 435 amps. Using that number and the 7.5 feet of 2AWG cable in the stock setup the voltage drop from 12v is 8.5% to 10.98v. A more likely draw of 350 amps showed a drop to 11.18v.

Changing from 7.5 ft to 10 ft yields net voltages of 10.64 (435 amps) and 10.91v (350 amps).

Those numbers don't seem all that material to me but what do I know. Like I said I'm not an engineer. Who can bring some expertise, please?

 

I don't know about those calculations either, but U can never go wrong with a very heavy gauge welding cable, when I used to instal batteries in trunk of vehicles, I allways used a heavy gauge welding cable & never felt a drop in starter output, the oversize cable might add max of 1-2,lbs compared to the cable U really need, but having reserve material in cable IMO is better than being right on the money or slightly more, & it keeps cables cool in an emergency overworked situation.(welding cables are usually pretty long , but u don't feel drop In AMPS when welding)

 

The situation you have is somewhat different since you're not extending the single cable from the battery, but the three cables from the control box to the winch motor. I'm not sure how that affects the load and I haven't had much luck trying to get an answer from from a winch mfg. Though i think I only tried Warn.
I'm doing a bit of research, hopefully I'll have an answer tomorrow.

 

Thanks, Tom. My logic, perhaps flawed, was that although I would be extending three cables power would be applied to only one of them at a time.

Separately, late yesterday I found at least one other winch manufacturer selling a set of extended length 2 AWG cables that were 67 inches long. While not quite 6 feet they are in the ballpark, indicating that at least that manufacturer considers that length cable acceptable.

 

IMO manufacturer cables are always too small.
When I did mine in a similar way, though a bit shorter, I used #1.
I should think you'd be good with #1 or definitely with 1/0.

FWIW, I make cables, so if you're interested let me know.

 

What is the Winch FLA rating?Post the manufacturer's name plate ratings.

 

435 is probably the FLA at stall (warn provides it at various loads, but not knowing which winch I can't say for certainty), or just before stall. Of course it will go even higher after stall, but hopefully he'd let off the switch if it stalls.

 

Yeah, the thing is when cable sizing for winches you can't get caught up focusing on FLA. there many other variables to consider. Winches are not rated for continuos use (as antichrist) pointed out above. Duty cycles or 'pulls' should be no more than ~1 minute in during.

 

I would throw a set of 1/0 or 2/0 welding cable on there and call it a day.

 

How about the small-gauge wire with the ring connector tagged "Motor Ground"?

In the standard setup it runs from one of the remote control terminals to the terminal on the bottom of the motor where the primary 2AWG ground cable attaches that runs to the battery.

To reach that terminal in my planned setup I'd need to splice in an extra several feet of similar gauge wire to reach the motor. But I don't know whether or not that is necessary. Can it instead be grounded anywhere else in the truck?