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View Full Version : Where to ground an aux fuse block to in an 80?


corsair23
07-16-2009, 12:30 AM
So all you smart 80 series owner who have installed an aux fuse block INSIDE the vehicle, where did you connect the ground from the aux fuse block to?

Obviously I don't want to run the ground all the way back to the battery right, but somewhere closer? This question came up in another thread and I answered in that thread and now I'm questioning my own answer :hill:

I plan to install the aux fuse block (Blue Sea 12 position block) under the PS inside the cab....I'm figuring that if I'm going to run power for my fridge it won't take much longer to just go ahead and install the aux fuse block and power the fridge off that :rolleyes:

Hants
07-16-2009, 06:31 AM
My fuse block is next to the passenger seat (see Christo's pictures).

I ran 2 4-gauge cables from that location, through the rubber nipples in the firewall and up to the aux battery.

There are 2 nipples in rubber. I cut the ends off, lubed the cable with gunk from Home Depo (cable lube), then chewed up my knuckles jamming the wire through (inside the cab to out in the engine compartment).

nakman
07-16-2009, 09:32 AM
My fuse block in back I'm grounded to the frame, one of those bolts that holds the little bar-shaped cross member. The one in front I have a common ground bolt near the main battery, that's also a battery ground in addition to numerous accessories. So yes if under the passenger seat I would go ahead and run the ground with the hot at the same time, and terminate it up in the engine common with one of your battery grounds. Not necessarily to the battery, but it's all going to be connected in the end.

And having "used up" the available space in the driver's side grommet, I'm now poking stuff through the grommet that Hants mentions.. it's tougher to access but if you pull the glove box you can eventually find it. But shove the wires from the engine, a lot easier on your knuckles!

jettaglxdriver
07-16-2009, 09:36 AM
In automobiles your chassis is your ground. You can ground your aux fuse box to the chassis closest to where it is installed and easy to attach.

Hants
07-16-2009, 09:41 AM
I didn't run do the chassis for 2 reasons:

1. From reading, it appears that the ground for your ham (and other radio equipment) is best done directly to the battery. I think this is due to noise (RFI).

2. My wiring, fuse box, fuses are all done to support up to 100A. I can't be sure that the existing grounds (and ground interconnects) are sufficiently low resistance to support high loads.

jettaglxdriver
07-16-2009, 09:46 AM
I have installed 1500watt car stereo amp that ground to the chassis. The key then is just making sure the chassis ground wire that goes back to the battery's negative terminal is upgraded also. I cannot speak on the Ham noise logic though since I don't have any experience there YET.

MDH33
07-16-2009, 09:55 AM
I just added the 6 position Blue Sea fuse block inside the cab of my 60 and I ran the ground back to the battery along with the positive.

corsair23
07-16-2009, 12:19 PM
Dang...I was hoping for a short (read easy) ground location :)

My buddy was telling me that you want short ground runs to reduce the chance of getting line noise etc. Of course the fact that I have 20' of power cable but only 7' of ground was helping to drive my decision process here. For the time being I won't have a dual battery setup so the runs to the battery will be longer short term (if there is such a thing for me). I figured when the time came to finally get the dual battery setup it would be a simple matter of changing the route of the positive cable in the engine bay to a shorter run to the aux battery, cut the cable, and redo the cable end.

Tim, do you have your Ham radio wired to the aux fuse block in back or direct to the battery?

Red_Chili
07-16-2009, 12:48 PM
In my case you are talking to a feller who ran 1/0 from the frame ground point next to the batteries in the back, up to a point in the frame near the engine, which serves as a ground point for the engine and the body. So no, you won't hear the answer you want from me! LOL

We typically draw up to hundreds of amps through our charging systems when winching, etc. I don't want to rely on the frame to carry that - especially as it ages, as things corrode, etc. I want ground to be GROUND. Electrons go funny places in unpredictable ways unless you provide a REALLY easy path for them to follow; then they abandon their friends and jump in the big river. Poor grounds can cause truly inexplicable behavior at times.

nakman
07-16-2009, 12:58 PM
Tim, do you have your Ham radio wired to the aux fuse block in back or direct to the battery?

In the 80 the power to the Ham (AND CB) is running through the engine bay fuse block, with a 20amp fuse, and also the in-line fuse that came with the radio. In the Taco the power is straight to the battery, and in both the ground is running all the way up to the battery- they all have in line fuses.

I know it's recommended to run Hams straight to the battery, but I think they say that just so folks don't use a paperclip in the radio fuse and then complain about interference problems, it's much "cleaner" to have it completely isolated, probably safer too. The real problem comes down to amperage and how much draw there is, and I can't tell you what that number is so I just rarely transmit on 50 watts and when I do it's very brief, and I'm into the 3rd year on this install and still going fine in my blissfully simple solution...

In the 80 my engine bay fuse block is HAM, CB, and engine lights on the "always hot" side, and rock lights, driving lights, OBA, and seat heaters on the "switched hot" side. No wait, the CB is switched on, crap.. well I'm not sure now but it's close to that. My cargo area fuse block is currently just two 12v cigarette lighter plugs on separate "always hot" circuits, and nothing in the available "switched hot" sides. One is for the fridge, the other is just a spare usually used for air mattress pumps and various chargers. As I add a sub and/or DVD players, etc. that'll get wired to the switched side of the cargo area fuse block.

My inverter and trickle charger for the camper also run straight to the battery, so they don't run through any fuse block but they do have those little brick fuse things.. I forget what they're called they came with the fuse blocks too.

corsair23
07-16-2009, 06:04 PM
Thanks Tim...

So you power the Ham off the aux fuse block but ran the ground all the way to the battery? I didn't even consider that...Does that effectively "increase" your total loop length or roundtrip length? Being the electrical noob I am I have tried to do a fair bit of reading and with regard to wiring size I read that you need to take into account the power run and ground run total length to size the wire correctly and limit voltage loss. I was figuring with the shorter power and ground runs coming off the aux fuse block the size of wire, and more important the voltage loss, would be minimized. With my aux fuse block planned to be under the passenger seat my power run to the Ham (and anything else inside) would be pretty short. I may add another aux fuse block in the engine compartment down the road for stuff that isn't inside (aux lights etc.)

I'm probably going overkill but I already bought a lot of the stuff gradually as I find a good deal so I'll be running 4ga wire to the aux fuse block. Thinking of what I plan to power off the block it will be the fridge (5.5A max), FT-8800 (8.5A max per manual), CB (<1A), and maybe up to 4 additional cig plug outlets scattered about (say 10A ea, 40A total). Grand total of 55 amps assuming everything is on and pulling max power. Of course I hadn't thought this far ahead and purchase 100A and 125A ANL fuses which are WAY too big :doh:

Well, now you know why I tend to never get anything done...Overthinking stuff is my specialty apparently rather than just doing it and adjusting on the fly or fixing it down the road.

sleeoffroad
07-17-2009, 08:02 AM
Jeff, why are you grounding the fuse block? I think those are made for boats where you don't have a chassis so you have to run separate ground runs. We never ground the fuse box. All circuits are grounded to the chassis at factory ground points that is suitable for the load you are running. As long as the battery is grounded properly to both the chassis and the body that is fine.

There is no need to run ground runs back to the fuse box. Just doubles the amount of wire and circuits. A good ideas is to also run any switching you do on the ground side of the circuits. That way it is similar to what Toyota does on all the circuits.

I know the ham purist would have you run power and ground from the battery directly, however unless you get interference from the power or ground source you can do it from a shared fuse box.

sleeoffroad
07-17-2009, 08:07 AM
I didn't run do the chassis for 2 reasons:

1. From reading, it appears that the ground for your ham (and other radio equipment) is best done directly to the battery. I think this is due to noise (RFI).

I think in the 2m world where most of the hamsters in the club play noise is not that big of an issue. Now those Millers with the big ol' towers on their trucks, grounding becomes a big issue.


2. My wiring, fuse box, fuses are all done to support up to 100A. I can't be sure that the existing grounds (and ground interconnects) are sufficiently low resistance to support high loads.

Upgraded chassis to battery and body to battery grounds will take care of this, although rarely needed provided they are in good shape. The only thing that we ground directly to the battery is a winch. The rest of the loads that you have in the vehicle can easily be handled by the chassis or body.

LARGEONE
07-17-2009, 12:24 PM
Thanks, Christo...what gauge do you upgrade the body ground to on a dual battery setup? 6? How 'bout the main ground to engine? 1/0?

Red_Chili
07-17-2009, 01:28 PM
1/0 is way overkill.

So I used it. :lmao:



But seriously, I had a mess of it and I just kept things consistent. Newer vehicles probably won't have any issues ever with much lighter gauge. I just had a long run from the rear of the truck, so... and I was concerned about voltage drop more than absolute current capacity.

Red_Chili
07-17-2009, 01:50 PM
Sooo... let's not call this thread hijacking... let's call it thread drift.

I have not yet fused my batteries in the back of the truck. But I am thinking I should, armored battery cables or not.

Not a bad option:
http://order.waytekwire.com/productdetail2/M37/46276/HIGH%20AMP%20FUSE%20250%20AMP/

These have a nice fuseholder option:
http://order.waytekwire.com/productdetail2/M37/46039/HIGH%20AMP%20FUSE%20HOLDER%20W/COVER/

Pondering loads. I am thinking 300A, what say Dave or Jeff or... ?
For those prices I really have NO excuse.

nakman
07-17-2009, 01:53 PM
Sooo... let's not call this thread hijacking... let's call it thread drift.

[/URL]

These have a nice fuseholder option:
[URL]http://order.waytekwire.com/productdetail2/M37/46039/HIGH%20AMP%20FUSE%20HOLDER%20W/COVER/ (http://order.waytekwire.com/productdetail2/M37/46276/HIGH%20AMP%20FUSE%20250%20AMP/)



That looks a lot like the one I've got on the ground for my 2nd battery. And I only run a 150 amp fuse, IIRC...

corsair23
07-17-2009, 03:04 PM
Jeff, why are you grounding the fuse block? I think those are made for boats where you don't have a chassis so you have to run separate ground runs. We never ground the fuse box. All circuits are grounded to the chassis at factory ground points that is suitable for the load you are running. As long as the battery is grounded properly to both the chassis and the body that is fine.

Well....Cause...Um, I don't really know :o. Being the electrical noob I am I did a lot of reading and this just seems to be how people do it. I just assumed you had to run power to the aux fuse block and then ground the block somewhere, whether near the fuse block to a factory ground or all the way back to the battery :confused:.

So you don't ground those Wrangler aux fuse blocks you install (I bought one of those from you 2+ years ago so that tells you how long I've been "thinking" of adding an aux fuse block :rolleyes:)?

So you are saying I can just run my 4ga + cable from the battery to the fuse block (fused of course), then run power off it to my accessories and ground those accessories to a "suitable" nearby ground point? Sounds too simple :cool:. With the aux fuse block under the passenger seat all my runs will be relatively short (power and ground) anyway but maybe taking the grounds back to the block isn't the best plan...

corsair23
07-17-2009, 03:09 PM
Pondering loads. I am thinking 300A, what say Dave or Jeff or... ?
For those prices I really have NO excuse.

Don't ask me! I think I've proven I know pretty much zero when it comes to electrical :hill: - All I think I know for sure is that you don't want to fuse it at 300A if your total load is only going to be 100A. Fuse it at something close to the max continuous amps expected, which tells me I won't be needing the 100A and 125A ANL fuses I bought, probably more around 50A. When I go dual batteries and since I have a winch, apparently I won't be fusing that stuff at all :confused: - Although I'm thinking maybe I might just fuse the leads anyway, in the 500A range...High enough for the winch draw but not so high that they'll never blow should something go horribly wrong.

jettaglxdriver
07-17-2009, 03:52 PM
Is there an echo in here? Who wires their winches off their aux fuse panels inside their trucks?


;)

corsair23
07-17-2009, 04:14 PM
Is there an echo in here? Who wires their winches off their aux fuse panels inside their trucks?


;)

Hopefully no one but you never know :rolleyes: - I think Bill is just considering protection given where he has to mount his aux battery and the long runs that stand a chance of causing serious issues. Better to have a fuse blow than the Red Chili catch on fire.

sleeoffroad
07-17-2009, 04:56 PM
So you don't ground those Wrangler aux fuse blocks you install (I bought one of those from you 2+ years ago so that tells you how long I've been "thinking" of adding an aux fuse block :rolleyes:)?

That is how the whole car works. Power to fuse box, power from fuse box to load (bulb, motor, whatever), then the other side to a chassis ground.

Blueseas come from the boat world where there is only fiberglass, so you have to run both sides.


So you are saying I can just run my 4ga + cable from the battery to the fuse block (fused of course), then run power off it to my accessories and ground those accessories to a "suitable" nearby ground point? Sounds too simple :cool:.

Yup


With the aux fuse block under the passenger seat all my runs will be relatively short (power and ground) anyway but maybe taking the grounds back to the block isn't the best plan...

There are ground points throughout the truck. Look at the schematic and you will find them. Or just look for the wires bolted to the truck.

corsair23
07-17-2009, 05:23 PM
Thanks Christo :thumb:

Obviously I've overly complicated this (again) whole thing. And, if I do end up getting any noise on my Ham I can always redo that and isolate it off by itself. I might have to rethink not using the Wrangler unit from you now...Do you sell the covers separately? Mine didn't come with one and I'd prefer to have the stuff covered/protected.

sleeoffroad
07-17-2009, 05:40 PM
Thanks Christo :thumb:

Obviously I've overly complicated this (again) whole thing. And, if I do end up getting any noise on my Ham I can always redo that and isolate it off by itself. I might have to rethink not using the Wrangler unit from you now...Do you sell the covers separately? Mine didn't come with one and I'd prefer to have the stuff covered/protected.

There is no cover for it. We made them to fit.

Red_Chili
07-18-2009, 12:58 AM
Hopefully no one but you never know :rolleyes: - I think Bill is just considering protection given where he has to mount his aux battery and the long runs that stand a chance of causing serious issues. Better to have a fuse blow than the Red Chili catch on fire.
Yep. Guess he missed the attempted thread drift... :lmao:
And that would be primary AND aux batteries under the rear deck. Explaining the fat gauge.
I figgered the other Jeff Z might pipe in...