Power to the back (pass side) of the 80... (1 Viewer)

[categorytheory]

So I’ve read enough threads to understand the electrical setup I’m going to wire to get power to the rear, but what I’m still questioning is how to get the actual 4 ga wire from the engine bay to the rear pass side without drilling a new hole on the firewall and going through the drive side wire port. Is this even doable and if so how to route it? Thanks.

 

[Shoredreamer]

One 4awg cable from the engine will pass thru the DS firewall grommet no problem, then you route it across to the passenger side via the footwell & tranny hump (behind the shift console & lower center air vent), then run it in along the door steps in the channel under the carpet.

 

[categorytheory]

One 4awg cable from the engine will pass thru the DS firewall grommet no problem, then you route it across to the passenger side via the footwell & tranny hump (behind the shift console & lower center air vent), then run it in along the door steps in the channel under the carpet.

Ok perfect!! Thank you!

 

[NorCalFJ100]

One 4awg cable from the engine will pass thru the DS firewall grommet no problem, then you route it across to the passenger side via the footwell & tranny hump (behind the shift console & lower center air vent), then run it in along the door steps in the channel under the carpet.

Do you run it through the same hole as the current wires or cut a new hole in the rubber? It doesn't really look like there's room to run the wires in the same hole.

I'm looking to do the same.

 

[Shoredreamer]

Do you run it through the same hole as the current wires or cut a new hole in the rubber? It doesn't really look like there's room to run the wires in the same hole.

I'm looking to do the same.

You may be thinking of the passenger side grommets? I only use the driver side quarter sided firewall pass thru grommet which has no wires going thru it. You basically cut open the grommet to the size you need to allow passing thru.

 

[deltapine1]

One 4awg cable from the engine will pass thru the DS firewall grommet no problem, then you route it across to the passenger side via the footwell & tranny hump (behind the shift console & lower center air vent), then run it in along the door steps in the channel under the carpet.

Are two cables not required to complete the circuit? I ran two 6awg to the back through the passenger grommet. I gave up at one point and consulted with a fellow 80 owner who had already done it. It is easier to pull wires from the back to the front. Use a stiff wire or coat hanger pushed through the grommet, tape the cable on the coat hanger and pull the coat hanger from the engine bay side.

 

[jpoole]

Are two cables not required to complete the circuit?

I relied on the chassis/body grounding to complete the circuit in my setup. I didn't need to add any ground connections beyond stock and have had no issues but will be interested to hear if additional grounding is needed in the experience of others.

 

[retrofive]

I relied on the chassis/body grounding to complete the circuit in my setup. I didn't need to add any ground connections beyond stock and have had no issues but will be interested to hear if additional grounding is needed in the experience of others.

This is what I did as well. Never was an issue.

 

[smritte]

If your using the existing body ground, it needs to be sized to how much power is being used in the circuit. Everything powered in your vehicle uses that same wire (except the engine). If you haven't noticed a difference, its because you haven't created enough bottle neck for a problem to be obvious.
The vehicle will start using other paths for the power flow. You could see a light on dim, it could travel along your throttle cable causing it to melt in the housing (ask me how I know this) or barely pull away from other components causing them to not work properly.
My winch is mounted to my frame, I use a 1/0 ground to the frame because of that, engine ground is 1/0 also and my body ground is a 2 gauge from battery to fender.
Overkill? Maybe but, I've seen enough issues with people not adding in enough to make the circuit work properly then end up with ghosts later that I have to diagnose.

@deltapine1 mentioned two cables. Your using the chassis as the negative side but it all comes back to the battery/alternator when its on.

 

[NorCalFJ100]

If your using the existing body ground, it needs to be sized to how much power is being used in the circuit. Everything powered in your vehicle uses that same wire (except the engine). If you haven't noticed a difference, its because you haven't created enough bottle neck for a problem to be obvious.
The vehicle will start using other paths for the power flow. You could see a light on dim, it could travel along your throttle cable causing it to melt in the housing (ask me how I know this) or barely pull away from other components causing them to not work properly.
My winch is mounted to my frame, I use a 1/0 ground to the frame because of that, engine ground is 1/0 also and my body ground is a 2 gauge from battery to fender.
Overkill? Maybe but, I've seen enough issues with people not adding in enough to make the circuit work properly then end up with ghosts later that I have to diagnose.

@deltapine1 mentioned two cables. Your using the chassis as the negative side but it all comes back to the battery/alternator when its on.

So if you are using 4awg for all your grounding straps and other chassis grounds, can you use the 4awg for the ground of your accessory fuse block and just make sure you have a good raw metal surface to attach that to?

Sorry I am learning daily about electrical!

 

[Shoredreamer]

Are two cables not required to complete the circuit? I ran two 6awg to the back through the passenger grommet. I gave up at one point and consulted with a fellow 80 owner who had already done it. It is easier to pull wires from the back to the front. Use a stiff wire or coat hanger pushed through the grommet, tape the cable on the coat hanger and pull the coat hanger from the engine bay side.

Not really. For the sake of the OPs question I mentioned one 4awg would fit thru the firewall grommet. Amazingly, I have fit up to 3 4awg cables, 6 10awg cables and numerous 16-22awg wires thru that ds firewall in the past.

Regarding accessory grounding, I have always made an effort to ground directly to the specific battery as often as possible. In addition, I have had good results adding a frame ground with a 4awg cable going down to the frame from both engine batteries and one on the psssenger side rear quarter panel battery down thru the sunroof drain grommet to the frame also. All 4awg, for charging and compressor and inverter. I’ve added a couple ground points on the body in the passenger rear 1/4 panel also.

The factory body ground points are as follows:
EA- right fender
EB-left fender
EC-firewall under accel cable
ID-left kick panel
IE-right kick panel
BF-under center console
BG-outside under tailgate/spare tire

There are plenty of addition straps going between the engine and body. Maybe somebody knows all these specifically. I guess my question is can you have too many ground points?

 

[lasoundguy]

I did 4AWG through the driver side grommet and a new 4AWG tied into the body ground in the passenger side footwell for my fuse distribution, and another 4AWG ground wire tied to the body for the fridge power in the back. Basically another take on what @Shoredreamer is describing.

 

[lasoundguy]

Forgot to mention, I am seeing a 0.2V drop between battery terminals and the fridge power at the back of the truck. Works for me.

 

[cvenom96]

I grounded mine at the back and ran the power as others have said through the DS grommet and past the shifter console. I did this when I was replacing all of the interior carpet so it was much easier than trying to fish things along past the seats and under the carpet. No issues with my setup and it reads a solid 14+ volts at the quarter panel.

 

[Broski]

I relied on the chassis/body grounding to complete the circuit in my setup. I didn't need to add any ground connections beyond stock and have had no issues but will be interested to hear if additional grounding is needed in the experience of others.

Same, I run a On board air compressor and an ARB fridge both on chassis ground.
zero problems

 

[cvenom96]

Just to add, mine is running a Kicker amp, 400w inverter, and USB ports in the console and rear doors.

 

[deltapine1]

Thank you @Shoredreamer and @lasoundguy for the info. I ran a complete circuit from + battery to the rear quarter and back to the - battery. Your info is valuable and would save a fair amount of time trying to pull two cables to the back. Pulling one would be easy.

 

[smritte]

There are plenty of addition straps going between the engine and body. Maybe somebody knows all these specifically. I guess my question is can you have too many ground points?

To answer this, yes and no.
Some years back, in the tuner world, people were installing these spider looking ground cables all over their engine. They claimed a big improvement. If there was any at all, the owner had an issue to start with. that was a waste of money. I've seen people install a series of 2/0 cabling to improve. That would be a waste of cable. think of wiring like a sprinkler system that picks the water back up and resprays it. If you have a feed system that flows enough water, would it benefit you to have twice the return if the pump cant flow any more? The other side would be, your return is too small and you have a restriction. This restriction in electricity is called a voltage drop. That's loss in the system caused by a number of things. Think of it a bottle neck. It can happen on the positive and/or the negative.