Wiring for a front winch

[Quest4vertical]

So, I've been reading a lot of threads and watching a lot of videos on how folks have solved the winch wiring issue. Specifically, making a home run from the 12v battery in the back to some type of wiring terminal under the hood. I thought I would share a few things here.

In a nutshell, I'm running 1/0 battery cable, positive & negative, from the battery in the rear to a terminal bracket under the hood. There will be a mega fuse holder very close to the battery on the positive wire in case of any catastrophic damage that could be caused in an accident. I'm going to start with a 250-amp fuse, most seem to be running this size without issue. However, the fuse holder can handle more amperage if needed. I will route the wire through the rear wheel fender well with waterproof wire glands as many have successfully done.

For the fuse holder, I came up with a simple bracket that will mount onto the battery tray cross support. I will post some pictures once installed. It's made to mount the Littlefuse Fuse Holder.

In the engine bay, in the empty space in front of the driver side fuse box, I will install this terminal bracket that will have two stand alone junction blocks. The wire will come from underneath and pass through the oblong slots that will have rubber grommets. The bracket will have room to mount an additional plate on standoffs above the junction blocks for future lighting control mounts.

I will post pictures as I progress through the install.

 

[BigMF]

I literally just did this 2 weeks ago with a few differences. I did NOT run a negative wire all the back and instead grounded directly to the chassis because the battery is connected directly to the chassis also. I'm still having some second thoughts about that option versus a dedicated wire.

How are you going to fabricate the brackets, especially the one up front? 3D-Print or metal?

If you don't want to drill any holes, you can get at least one 1/0 gauge wire and possibly two through the grommet in the rear quarter panel behind and below the 12V battery. See below where the grommet is (battery, battery tray, and jack mount removed). I ordered some of those waterproof glands for 1/0 gauge wire and they are massive. You have to drill a hole that is something like 1.25" in diameter.

External location:

 

[Quest4vertical]

I literally just did this 2 weeks ago with a few differences. I did NOT run a negative wire all the back and instead grounded directly to the chassis because the battery is connected directly to the chassis also. I'm still having some second thoughts about that option versus a dedicated wire.

How are you going to fabricate the brackets, especially the one up front? 3D-Print or metal?

If you don't want to drill any holes, you can get at least one 1/0 gauge wire and possibly two through the grommet in the rear quarter panel behind and below the 12V battery. See below where the grommet is (battery, battery tray, and jack mount removed). I ordered some of those waterproof glands for 1/0 gauge wire and they are massive. You have to drill a hole that is something like 1.25" in diameter.

View attachment 40268

External location:
View attachment 40269

The folks over at Borne [the winch I will probably get] say to run a negative directly to the battery. So, I'm going that route. Definitely more difficult. I have seen it done your way and I haven't heard of any issues, so not sure what the answer is there.

Yea, the glands are scary big, a lot bigger than I pictured. But there is plenty of room on that flat spot in the wheel well for the 2 glands. Most are using the 1" NPT gland; however, I found the 3/4" fits the 1/0 cable better and it's 1.025" in diameter at the thread so they have more clearance around the nuts.

The 2 brackets are laser cut from steel. The smaller battery tray bracket is 16g steel and powder coated flat black. It has 8-32 PEM nuts on the back for easy mounting. The front terminal bracket is 12g 304 stainless with a flat black powder coat. I'll post some pictures once I finish them.

How difficult was disassembling the rear trim and battery tray? You took the interior trim panels off?

Side note: I have seen a lot of folks run the 1/0 through the gland with a mesh wire loom on the cable; it's not 100% watertight that way. The gland can't get a perfect seal over the mesh. I leave the mesh off for the very short distance through the gland.

 

[ultane]

I literally just did this 2 weeks ago with a few differences. I did NOT run a negative wire all the back and instead grounded directly to the chassis because the battery is connected directly to the chassis also. I'm still having some second thoughts about that option versus a dedicated wire.

I am NOT an electrical engineer, but I did stay at a Holiday Inn Express a couple of weeks ago.

That’s a lot of current, traveling to a lot of places, even if only rarely, to potentially mess up a lot of OEM Toyota bit’s and pieces.

I would run the wire..

 

[BigMF]

I am NOT an electrical engineer, but I did stay at a Holiday Inn Express a couple of weeks ago.

That’s a lot of current, traveling to a lot of places, even if only rarely, to potentially mess up a lot of OEM Toyota bit’s and pieces.

I would run the wire..

Dang it! I hate you @ultane! Now I'm REALLY stressing about it.

Fortunately (or unfortunately), I'm probably not going to be in a position where I'll actually need to use the winch in the very near future. However, I'll probably look at running the wire next month. My financial budget as well as my wife-ok-with-me-working-on-the-truck-instead-of-spending-time-with-her budget is nearly maxed out for June.

 

[Quest4vertical]

Dang it! I hate you @ultane! Now I'm REALLY stressing about it.

Fortunately (or unfortunately), I'm probably not going to be in a position where I'll actually need to use the winch in the very near future. However, I'll probably look at running the wire next month. My financial budget as well as my wife-ok-with-me-working-on-the-truck-instead-of-spending-time-with-her budget is nearly maxed out for June.

Now that you said, "I'm not going to have to use the winch", you will most definitely be using it tomorrow.

 

[BigMF]

The 2 brackets are laser cut from steel. The smaller battery tray bracket is 16g steel and powder coated flat black. It has 8-32 PEM nuts on the back for easy mounting. The front terminal bracket is 12g 304 stainless with a flat black powder coat. I'll post some pictures once I finish them.

I'm jealous of the access to a fabricator or shop that will do that for you. Have you considered using aluminum instead of steel for its superior rust resistance? May be too late since it sounds like you already have them in hand. Also, from what I've read, most types of aluminum don't bend very gracefully.

How difficult was disassembling the rear trim and battery tray? You took the interior trim panels off?

So, I've taken the rear trim off multiple times now (sound deadening, etc.) it gets easier each time. I know it sounds like overkill but I take the metal cage/cover over the hybrid battery off (8 bolts) and then pull the interior trim on the side. Having the trim out of the way is a game changer and removing the metal cover over the hybrid battery is very easy and makes removing the trim MUCH easier to do without breaking anything. It took me about 10-15 minutes total to get to where the trim was completely off. Well worth the investment in time to not have to try and poke both hands and tools through the opening in the trim. There is a thread I started about removing interior trim that you may find helpful. The tray for the battery and the jack mount were simple once you get the trim and battery out of the way.

Side note: I have seen a lot of folks run the 1/0 through the gland with a mesh wire loom on the cable; it's not 100% watertight that way. The gland can't get a perfect seal over the mesh. I leave the mesh off for the very short distance through the gland.

Yeah, I also thought about the "watertight'ness" with the mesh loom but figured if I'm in water that deep, it's going to already be coming in through the small vent right next to that grommet. Also, there are two trim clips right there as well and you can see daylight peeking through around them. No GREAT solutions, we just have to make the best of some adequate options in my opinion.

Last but very much not the least, be sure to hook your positive up to the screw that holds the battery clamp on to the post and NOT the very convenient screws on the front or top of the cable that is already connected. Apparently, if you connect to one of those spots, you risk frying that "link" with the fuses in it and you have to replace the whole unit and reportedly costs well north of $1,000, especially when you factor in labor. You can ask @JordanJ about it if you need more details.

 

[Quest4vertical]

I'm jealous of the access to a fabricator or shop that will do that for you. Have you considered using aluminum instead of steel for its superior rust resistance? May be too late since it sounds like you already have them in hand. Also, from what I've read, most types of aluminum don't bend very gracefully.

I would definitely consider aluminum and actually I only have a prototype made at this point. I figured the stainless-steel is corrosion resistant enough. The aluminum would bend fine as I have bend relief cuts in the top of the part.

Last but very much not the least, be sure to hook your positive up to the screw that holds the battery clamp on to the post and NOT the very convenient screws on the front or top of the cable that is already connected. Apparently, if you connect to one of those spots, you risk frying that "link" with the fuses in it and you have to replace the whole unit and reportedly costs well north of $1,000, especially when you factor in labor. You can ask @JordanJ about it if you need more details

Dissent attaches to the top post that you have crossed out, so that must be safe. The other two you have crossed out are definitely the risky ones.

Ha-ha, I didn't realize there are so many little spots that aren't watertight! In that case I'm going to run the mesh loom right through the grommet.

 

[Quest4vertical]

Last but very much not the least, be sure to hook your positive up to the screw that holds the battery clamp on to the post and NOT the very convenient screws on the front or top of the cable that is already connected. Apparently, if you connect to one of those spots, you risk frying that "link" with the fuses in it and you have to replace the whole unit and reportedly costs well north of $1,000, especially when you factor in labor. You can ask @JordanJ about it if you need more details.

That post you attached to looks like it doesn't require the thick washer needed on the front post? Probably the better option.

 

[BigMF]

Dissent attaches to the top post that you have crossed out, so that must be safe. The other two you have crossed out are definitely the risky ones.

Yeah, that one is probably safe since it's "before" the fuses. However, if you connect to the one in the back, it's a bit easier to re-use the OEM cover to protect all those charged, metal points. I only had to do a small amount of trimming to be able to clip that original cover back into place and still have the protection it provides. Just something to think about.

 

[BigMF]

That post you attached to looks like it doesn't require the thick washer needed on the front post? Probably the better option.

Yeah, I think you'd need a thick washer under the lug to avoid the "lip" around that post on the front one:

 

[BigMF]

One other thing, FYI, that bolt at the back is the one you loosen to get the terminal off of the battery post. It's a different "style" than I've seen before such as the old school lead terminals. Hard to explain how it works but essentially, as you tighten the bolt, it forces a u-shaped bracket down over the ends of the terminal, squeezing them together.

 

[Quest4vertical]

One other thing, FYI, that bolt at the back is the one you loosen to get the terminal off of the battery post. It's a different "style" than I've seen before such as the old school lead terminals. Hard to explain how it works but essentially, as you tighten the bolt, it forces a u-shaped bracket down over the ends of the terminal, squeezing them together.

Have you load tested you winch?

 

[BigMF]

Have you load tested you winch?

Load tested in which way? Pounds or AMPs drawn? The answer is 'not yet' to both but wasn't which you were referring to.

 

[Quest4vertical]

Load tested in which way? Pounds or AMPs drawn? The answer is 'not yet' to both but wasn't which you were referring to.

I was more thinking just pulling your rig up a nasty hill to see what happens!

 

[BigMF]

I was more thinking just pulling your rig up a nasty hill to see what happens!

Ahh, not yet. Just finished on Sunday and haven't gotten the chance to wind the winch rope up properly onto the spool. Maybe this weekend I'll do a bit of a test but need to find a good hill with a good tree at the top.

 

[MaximusLC]

So, I've been reading a lot of threads and watching a lot of videos on how folks have solved the winch wiring issue. Specifically, making a home run from the 12v battery in the back to some type of wiring terminal under the hood. I thought I would share a few things here.

In a nutshell, I'm running 1/0 battery cable, positive & negative, from the battery in the rear to a terminal bracket under the hood. There will be a mega fuse holder very close to the battery on the positive wire in case of any catastrophic damage that could be caused in an accident. I'm going to start with a 250-amp fuse, most seem to be running this size without issue. However, the fuse holder can handle more amperage if needed. I will route the wire through the rear wheel fender well with waterproof wire glands as many have successfully done.

For the fuse holder, I came up with a simple bracket that will mount onto the battery tray cross support. I will post some pictures once installed. It's made to mount the Littlefuse Fuse Holder.

In the engine bay, in the empty space in front of the driver side fuse box, I will install this terminal bracket that will have two stand alone junction blocks. The wire will come from underneath and pass through the oblong slots that will have rubber grommets. The bracket will have room to mount an additional plate on standoffs above the junction blocks for future lighting control mounts.

I will post pictures as I progress through the install. View attachment 40208

Can we group buy these things? Love me some clean brackets.

 

[Quest4vertical]

Can we group buy these things? Love me some clean brackets.

Yea, if we get a decent group they will be very reasonable.

 

[Bad1975]

I wouldn't stress on a dedicated winch ground wire going to the battery, ground is ground and since the battery is grounded to the chassis, drivetrain and body in multiple locations a dedicated winch ground to the battery is a redundancy item.

If the resistance through the frame to the winch is lower than the ground cable you ran to the battery the current will travel through the frame vice the cable (path of least resistance).

Also for folks that think the ground wire will protect other components from the current drawn from the winch it won't, everything requiring power is attached to ground and therefore connected to one another via the common ground, there is no way around it unless the component is operating on a floating ground (not used in the automotive world). The more sensitive items (ECUs and such) have reverse current protection on their ground points and I've never seen one of those fail ever.

I installed a dedicated ground wire to the battery when I did mine but no harm will come without one, I installed purely for redundancy and the ability to wire multiple items to the new negative battery post I installed under the hood. It's also nice for jump starting or hooking up a charger but as discussed the dedicated ground wire still isn't required for either.

FYI, I've been working in electronics/electrical for 32 years on much higher tech and sensitive equipment, you'll be fine with or without it.

 

[Quest4vertical]

I wouldn't stress on a dedicated winch ground wire going to the battery, ground is ground and since the battery is grounded to the chassis, drivetrain and body in multiple locations a dedicated winch ground to the battery is a redundancy item.

If the resistance through the frame to the winch is lower than the ground cable you ran to the battery the current will travel through the frame vice the cable (path of least resistance).

Also for folks that think the ground wire will protect other components from the current drawn from the winch it won't, everything requiring power is attached to ground and therefore connected to one another via the common ground, there is no way around it unless the component is operating on a floating ground (not used in the automotive world). The more sensitive items (ECUs and such) have reverse current protection on their ground points and I've never seen one of those fail ever.

I installed a dedicated ground wire to the battery when I did mine but no harm will come without one, I installed purely for redundancy and the ability to wire multiple items to the new negative battery post I installed under the hood. It's also nice for jump starting or hooking up a charger but as discussed the dedicated ground wire still isn't required for either.

FYI, I've been working in electronics/electrical for 32 years on much higher tech and sensitive equipment, you'll be fine with or without it.

Good info, thanks. Tell us about your winch. Have you used it much? How does it perform under load? Do you have a fuse at the battery? If so what size? Wire size you ran to the front?