How to / Where to Connect to Factory Electrical Wiring (Pics)

forlexinotme

New member
I know this information is available elsewhere on the forum, but I thought we could start a thread where it is consolidated a bit. There are many ways to tap into the existing factory wiring to connect dual batteries, run house loads, etc. Here is where I have found you can make straightforward connections with pictures. These are not the only ways, but I have used each of these and know it can be done safely. I have not worked with the fuse block/relay box under the co-drivers feet. If someone else had, hopefully they can add to this.

For positive connections there are 3 main spots depending on your vehicle options (details and pics to follow in other posts):
  1. Terminal Strip EK1, located in the drivers seat base, aft, inboard corner
  2. Fuse Block F150/4, located in the drivers seat base, center, outboard on the bottom
  3. Fuse Block F150/1, located in the main battery compartment under the drivers feet, connected to the positive terminal.
For negative connections there are a few options (no pics, they look like bolts with grey varnished nuts):
  1. There are three grounding studs in the drivers seat base, under the mount for the PSM/other control modules on the inboard side just forward of EK1. All of my studs already had ring terminals attached to them, but there was enough length to add 1 terminal per stud.
  2. There is an exterior stud just forward of the rear axle on the right hand side of a cross member. Again, it had ring terminals on it, but I was able to add a 2/0 wire/ring terminal that was .090" thick.
  3. There is a stud in the interior rear of the van, drivers side, top corner. It is heavily utilized on my van, but could probably take 1 more terminal.
  4. According to the upfitter Body and Equipment manual there is another stud under the floor, near the right hand sliding door, see page 252. My van does not have this stud. It may only be for certain body types.
 

forlexinotme

New member
Terminal Strip EK1 Details

EK1 is located in the drivers seat base, aft, inboard corner.
Drawing EK1.jpg

EK1 provides three terminals which have over-current protection already and are powered under different vehicle conditions (alternator on, direct battery, ignition on). It is pretty well detailed on page 245 of the upfitter BEG document freely available online. Here is a screen shot with some of the detail
EK1 Terminals.png

This one is very straight forward. Just terminate to the studs with ring terminals with the appropriate wire size for the available current.
 

forlexinotme

New member
F150/4 Fuse Block Detail

Fuse Block F150/4 is located in the drivers seat base, center, outboard on the bottom. It can be hard to see because of all the wires feeding the fuse blocks on the outboard side of the seat base (where the door is at). Look for at least 4 BIG wires going into a black mystery box. You cant miss it. To access the block I removed the K100 relay rail mount to the top of the seat base and removed F55/1 through F55/6 (all the fuse block rails that you access from behind the plastic door) so I could push the wires out of the way. You must then remove any wires terminate to the studs. By removing the wires you can then loosen the clips on the cover and remove it. If you do not remove the wires, your cannot remove the cover.

What is connected to F150/4 will vary widely depending on your vehicle options. Everything that follows is based on my van which has the premium package and parking package. I do not have a second alternator, powered steps, rear a/c, etc. etc. Check your option list then consult pages 11 and 12 of your "Fuse Assignment Supplement" which should have come as a separate booklet with your owners manual. This will tell you what all the possible connections are and you will have to work back to see what may be available.

20210123_121820.jpg

This is the block is fed power on terminal #4 via an approximately 2 awg cable that goes directly to the battery and is fed from F150/1. There is no circuit protection on this main wire. On my van terminals 6 and 7 are not utilized, but the bus bar extends to these positions. The 80 amp midi fuse was already in place from the factory. I was able to simply add another MIDI fuse to terminal 7. This provides me with two, high amperage tapping points right in the seat base, fed directly from the battery. As you can see, terminal positions 8 through 13 are not available and those bus bars are not installed. If you have other options these may or may not be present. I am utilizing the 80 amp connection to run auxiliary loads via a fuse block. I am utilizing the terminal 7 connection to run a battery to battery charger to charge my house batteries. The small studs are M6x1, you will need to provide your own nuts.
 

forlexinotme

New member
Fuse Block F150/1 Detail

Fuse Block F150/1, located in the main battery compartment under the drivers feet, connected to the positive terminal via a post with a 13mm nut. Once you remove the nut you will be able to pull up on the plastic fuse block/cover and pull it out to work on it. Just pop open the cover by undoing the plastic clips.

20210123_144700.jpg

Inside there are limited connections but a few options:
20210123_145336.jpg

On my van there is an extra terminal next to the main cable that goes back and feeds F150/4. The distance between this terminal and the one to the left in the photo above is exactly right for a MIDI fuse. Unfortunately the factory bus bar is not connected to the supply terminal. A few other posts around the form have folks making their own bus bar to jumper over.


20210123_144832.jpg
Here is an example of what I did as a temporary solution. Its basically an 1/8 piece of copper bar stock whittled out to fit. Not pretty, but it worked for a few months before I removed it. I had to use spacers under the bar/fuse to get everything to line up. At work I have access to copper washers, so this was no problem for me but this is NOT the way to do this. Ideally you would make a new bar that would connect everything and that will eliminate the need to have dodgy spacers.

Ultimately I am not using this connection anymore, as I have plenty of space available on F150/4 and this eliminated the need to make a bus bar. It also keeps everything in the battery compartment factory. If you want to use this option, search for the other threads where folks are making these bus bars, there as some good photos/descriptions out there.
 

forlexinotme

New member
F150/5

F150/5 is an optional fuse block next to the EK1 terminals on certain vans. F150/5 is not an option on my van. As I understand it, this is only present when you have the factory auxiliary battery installation. This may or may not be accurate, as I said I dont have it so I cannot comment on what may or may not be available through it.
 

goldihop

Member
F150/4 Fuse Block Detail

Fuse Block F150/4 is located in the drivers seat base, center, outboard on the bottom. It can be hard to see because of all the wires feeding the fuse blocks on the outboard side of the seat base (where the door is at). Look for at least 4 BIG wires going into a black mystery box. You cant miss it. To access the block I removed the K100 relay rail mount to the top of the seat base and removed F55/1 through F55/6 (all the fuse block rails that you access from behind the plastic door) so I could push the wires out of the way. You must then remove any wires terminate to the studs. By removing the wires you can then loosen the clips on the cover and remove it. If you do not remove the wires, your cannot remove the cover.

What is connected to F150/4 will vary widely depending on your vehicle options. Everything that follows is based on my van which has the premium package and parking package. I do not have a second alternator, powered steps, rear a/c, etc. etc. Check your option list then consult pages 11 and 12 of your "Fuse Assignment Supplement" which should have come as a separate booklet with your owners manual. This will tell you what all the possible connections are and you will have to work back to see what may be available.

View attachment 168625

This is the block is fed power on terminal #4 via an approximately 2 awg cable that goes directly to the battery and is fed from F150/1. There is no circuit protection on this main wire. On my van terminals 6 and 7 are not utilized, but the bus bar extends to these positions. The 80 amp midi fuse was already in place from the factory. I was able to simply add another MIDI fuse to terminal 7. This provides me with two, high amperage tapping points right in the seat base, fed directly from the battery. As you can see, terminal positions 8 through 13 are not available and those bus bars are not installed. If you have other options these may or may not be present. I am utilizing the 80 amp connection to run auxiliary loads via a fuse block. I am utilizing the terminal 7 connection to run a battery to battery charger to charge my house batteries. The small studs are M6x1, you will need to provide your own nuts.
Do you happen to know what size and thread pitch those connections are?
 

Built.Vans

'19 4x4
To confirm, yes F150/5 is present with the auxiliary battery option. I have the auxiliary battery mounted under my hood and have tapped into the F150/5 fuse box to power my Victron Orion DC-DC charger. But I am currently working on a van that does not have this option and thank you for posting this as I will be tapping into the F150/4 to power their DC-DC charger. Question though, do you know if this is a constant connection, even when the van is off? I don't want to run the risk of draining the starter battery. Or will I also have to tap in the EK1 (ignition on) to trigger and turn off the DC-DC? I do not have this issue on my van as the DC-DC charger disconnects when voltage drops below a certain point.
 

moses

Member
To confirm, yes F150/5 is present with the auxiliary battery option. I have the auxiliary battery mounted under my hood and have tapped into the F150/5 fuse box to power my Victron Orion DC-DC charger. But I am currently working on a van that does not have this option and thank you for posting this as I will be tapping into the F150/4 to power their DC-DC charger. Question though, do you know if this is a constant connection, even when the van is off? I don't want to run the risk of draining the starter battery. Or will I also have to tap in the EK1 (ignition on) to trigger and turn off the DC-DC? I do not have this issue on my van as the DC-DC charger disconnects when voltage drops below a certain point.
I also have an under hood factory aux battery. The supply for my DC-DC is connected to the F150/5. I use the EK1 to trigger my DC-DC charger. I ran a wire from EK1 #1 to a dash switch, through the temperature relay on my BMV, and then to the enable port on my DC-DC. This all might be a little extra but I like the ability to shut the DC-DC off. The temperature relay just disables charging in low temperatures for my LiFePo pack.
 

hilld

Active member
This is a great place to consolidate all of the info. What I would add in one of your posts perhaps so it is at the top of this thread rather then buried back here is the proper way to disconnect the batteries and fuses that connect / disconnect the small lithium battery under the seat (lane assist and other functions) so you don't set off the airbag light when removing the seat to get to the components under the drivers seat.
 

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