Dual battery install: DONE! - Uh, Sort of...

4x4junkie

Explorer
I mentioned this in post #3 in this thread,

Your post (and the link within it) names tools that will do a 360° (hex or diamond) crimp (and you show a cross-sectional of one a couple posts later), it doesn't directly mention the importance of it. Without emphasis on this it tends to slip by without notice. There are several mentions of a hammer-crimper in the thread your link is from (which you did say you didn't care for)... This is the very tool that was used on many of the ones I've had fail/burn up. It creates a double-standard when you say soldering has all these caveats to getting a good connection while "forgetting" that crimping has just as many (if not more) caveats.

I'd be extremely surprised to see a terminal crimped onto an oxidized wire be even half as good as one crimped onto a clean wire. Oxidation is non-conductive and may be porous too, so all you're doing is crimping a layer of insulation around each strand into your connection and creating a failure point.
 

Martinjmpr

Wiffleball Batter
Well, thanks to Dave I now have properly (and safely!) crimped cables. Haven't had a chance to put them in yet but I'll get to that this week. After that my next task will be to push some 10g wire through the firewall and along the floor so I can install a 12v double outlet on the rear fender cover/body panel for the fridge.
.
Dave was also nice enough to help me tune my 2m antenna so that if/when I get around to installing my 2m mobile I'll have a decent communications setup.
.
After that's all done I just need new tires and then I'll have the truck set up for our trip to AZ in less than 3 weeks! :sombrero:
.
Anyway, thanks again to Dave in Denver and all the others who gave me good tips on how to get my system safely set up!
 

Martinjmpr

Wiffleball Batter
Put back together (pics)

OK, put it all back together tonight. Here are the nice, neatly crimped cables that Dave made for me:
.
DB13.JPG
.
Sweet, right? :elkgrin:
.
My experience with Dave using shrink tubing prompted me to go out and buy a heat gun and re-do my small cables, so instead of the "redneck mechanic" look of multiple wraps of black electrical tape, I have this:
.

db15.JPG
.
db14.JPG
.
Once I got those made, I popped the cover off of the fuse box so I could route the power wire for the controller underneath it. It's easy to remove the cover to the box, but you do have to take off the crescent-shaped hood brace in order to get it out.
.
db16.JPG
.
Got everything hooked back up...
.
db17.jpg
.
Tested it and...it didn't work. Then, after frantically checking every circuit, I realized that I'd re-connected all the cables - except the one from the house battery to the truck ground! :rolleyes:
.
Hooked that up and measured the voltage. Engine running, starter battery: 14.33v. House battery: 14.33v. :wings:
.
Looking into the engine compartment there are the ends of two machine screws sticking out. I was thinking this would be a great place for my insulated clamps.
.
db19.JPG
.
Only thing is, I don't know what nut size goes on here. Any ideas?
.
Should be the same as this screw on the driver's side above the ground strap:
.
db20.JPG
.
I assume this is a metric size, but I don't know. Any ideas?
.
Thanks again to everyone on this board who helped me with this and a BIG thanks to Dave in Denver who not only lent me his crimper but also a lot of good, practical knowledge! Oh, and then he tuned my 2m antenna for me!
.
The best thing about this board is the way folks are willing to help out others, share their knowledge and (even better!) their experience.
,
Anyway, next project will be getting power to the passenger compartment for the fridge, but I think I will post a new topic for that one. If anyone has any questions feel free to shoot me a PM or post up here.
.
And BTW I just want to point out that if I can do this project, as ignorant and fumble-fingered as I am, then pretty much anyone can do it. :sombrero:
 

rayra

Expedition Leader
Pretty sure it was a 10mm nut. I'll check.

eta it is

I used the stud on the driver's side outboard of the grounding strap location closer to where the wiring loom for the hood light passes.
And the same one on the passenger side, near the trans dipstick.
I was able to orient my cable clamps 180deg opposite of yours, tucked up high against the cowl, but mine probably fit because I only used a 1/2" size and no split loom and only passed one cable there.
 
Last edited:

4x4junkie

Explorer
The best thing about this board is the way folks are willing to help out others, share their knowledge and (even better!) their experience.

Sure thing. Glad to hear you made a new friend and you got it straightened out. Experience is the best way to learn things, because that is how you know if something actually works or if it doesn't work. ;) Hard to argue with that.

FWIW, those screws sticking out with nothing on them look like they have a very coarse thread, like maybe for some sort of plastic screw-on fastener. Hard to tell for sure though.
 

Martinjmpr

Wiffleball Batter
I'm just a squirrel, looking for a nut!

"I'm just a squirrel, looking for a nut! " :sombrero:
.
Drove the truck over to Ace Hardware hoping to find a nut to go on those screws sticking out from the firewall to mount my clamps. We tried and tried a bunch of different ones with no luck. Metric, SAE, didn't matter, everything we tried was either too big, too small or didn't fit the threads.
.
Then the guy working there told me about something called "Speed nuts" - made of soft metal (aluminum?) and hollow they have an oval-shaped opening and they sort of "adapt" themselves to an odd sized screw. Worked like a charm:
.
db21.JPG
.
Now, the thing about these speed nuts is, like I said, they're on the flimsy side. I would certainly not count on using them multiple times as I'm sure the fit would get sloppy and they might pop off. On the other hand, they're super cheap ($0.30/ea) so at that price I can get a pocket full of them and if/when I need to take a speed nut off, I'll toss it in the trash and put a fresh one on when I re-attach.
 

rayra

Expedition Leader
weird. When I did mine I just dug in my coffee can of 'spare' fastener hardware, found a couple that fit and yesterday I went out and put my 10mm wrench on them (again) just to be sure.

eh, whatever works, it's not a critical thing. And GM has been so freely and oddly mixing metric and SAE fasteners on their vehicles for so many years that I long ago quit giving a damn about it. You just learn which are which as you go and you get the tools you need to handle both.
 

Martinjmpr

Wiffleball Batter
Finally REALLY done!

Ah, finally finished up the project. As usual, it turned out to be much more work than I thought it would.
.
There's a cautionary tale here, too, about making sure you have the right tools and not being so impatient to get something done that you rush through the process and break something.
.
With the dual battery system functioning it was now time to turn to the whole reason WHY I put the dual battery in in the first place: So I could have a dedicated power source to run the fridge (among other things, but the fridge was priority no. 1.) In order to do that, I had to get power from my 2nd battery to the interior compartment of the truck.
.
This turned out to be a major hassle. I tried to push a wire through one of the existing wire grommets but no luck. At this point I didn't want to run the risk of damaging a critical electrical circuit so I tried to figure out what to do next. The only thing I could think of was to run the wire underneath the fender to the door, then poked a hole and ran it right through the door weatherstripping and from there I could drop it into the channel underneath the sill plate.
.
db26_zpsnljr8mwh.jpg

.
Looking at that, I'm thinking it would be prudent to either put some wire loom over the wire or even some rubber tubing to protect the wire from damage (the door does NOT contact the wire - I checked - but I don't want to run the even the risk of a bare wire shorting it out (although it is fuse protected at the battery end.)
.

It's not a particularly elegant solution, but given the fact that I was running out of time it was all I could come up with. I wish there was an easier way to put a wire through the firewall - I have to say that of all the tasks I've had to do on a vehicle, figuring out how to do this seemingly simple one has proved to be the most difficult of them all.
.
In the old days it was easy but modern vehicles have so much CRAP underneath the dash that it's nearly impossible to get through the firewall in a manner that is safe and "elegant" without looking like a hack job (It would be nice if manufacturers just put a blank "accessory grommet" somewhere on the firewall for just such things. Oh well, a man can dream, right? :rolleyes: )
.
Anyway, I was able to get most of the interior trim panels out - as others have said, they are held in with clips that just pop out. The only problem I had was with the one on the interior of the D-pillar. Since my Suburban has speakers there, the D-pillar is somehow held on with the speaker. I ended up pulling it just a little to hard and this was the result:
.
db22_zpsb27rh7hh.jpg

.
I couldn't see any way to remove a screw or anything so I still don't know how that panel is supposed to come off. Luckily for me, all the other panels came off without too much drama. The result was an interior that looked like this:
.
db23_zpsszeblsaj.jpg

.
My plan was to find a way on the fender-cover to put the dual 12v outlet. Finding a place that was both high enough that it would not be covered up by cargo, and also not on a curved portion of the panel, proved to be a little bit difficult but after looking around, I finally decided to mount the 12v outlets horizontally just behind the 3rd row seat cup holder.
.
Unfortunately, this was another area where my impatience cost me: I needed to drill a couple of 1" holes for the 12v outlets. I didn't have any actual 1" hole saws but I did have a spade bit. Of course, spade bits work great for wood - for plastic, not so much. The first hole went OK because I took my time but I rushed the 2nd hole and the result was not pretty:
.
db24_zpsij7tbimm.jpg

.
Yup, it punched out a section that was a good 1/4" bigger than it needed to be. I was able to smooth out the edges with a dremel tool and luckily for me, the cover plate for the outlet hides most of my mistake:
.
db25_zpsgjx9qb3t.jpg

.
For a ground I just ran a wire to the metal bracket that holds the fender cover up (the aluminum bracket you can see sticking out from the side of the body in the photo above.) I checked it with the volt meter and was getting a good solid 12.4v reading, so after that I hooked up the outlet and buttoned everything up.
.
Unfortunately while reassembling the plastic panels I broke off one of the smaller pins on the fender cover. Not a huge deal, but, once again, it shows the results of impatience (it was getting dark by this time and I just wanted to be DONE!)
.
You can see from the picture that there are two outlets - one is a conventional 12v power outlet and the other is a dual USB. The USB is not currently connected to anything but eventually I'll hook it up, probably by splitting the 12g wire that comes from the battery. I had thought about running another wire all the way from the battery but I don't think that's neccessary - USB has such a small power draw and it's not like we're going to connect that to anything other than a cell phone or iPod. If I had to do it over again I'd have just gone with the single 12v outlet. Easier to position and easier to fit in.
.
So, overall I have to say I learned a lot in doing this. And of course I have to thank all the folks here on the board who helped me out, especially Dave! I certainly could not have done it without you!
.
Even though this is "done" I will probably continue to "tweak" it but at least now I have a working system.
 

dwh

Tail-End Charlie
You know the old school 12v tester that looks like an icepick with a light in the handle?

It has a sharp point so it can penetrate insulation and poke directly into the copper anywhere along the wire.

That point also works for adding an extra hole in a grommet to poke an extra wire through.
 

Martinjmpr

Wiffleball Batter
You know the old school 12v tester that looks like an icepick with a light in the handle?

It has a sharp point so it can penetrate insulation and poke directly into the copper anywhere along the wire.

That point also works for adding an extra hole in a grommet to poke an extra wire through.

Tried that (with a sharpened screwdriver) but still couldn't get the wire through, even the fairly stiff 12g wire. The grommet was a very, very thick one. But it was the only one I could easily access from both the engine compartment and the interior of the truck. The harder I pushed, the more the grommet itself actually started coming away from the hole in the firewall and I didn't want to push it so far that the grommet popped out.
 

rayra

Expedition Leader
christ, might as well have used a hatchet. Should have contacted me again, I could have talked you thru it. As I described in the earlier PM, all those panels pull off in a direction straight away from the face they are attached to. Same goes for that D pillar panel at the rear, with the tweeter in it. There's a short lead on that, enough to get the plastic loose and then you dislodge the speaker from a couple plastic clips holding it to the panel. Then the panel is free and clear.

As for wiring, there's a huge main electrical bundle that passes thru a large gasket / grommet / bellows in the firewall. Has all the room in the world to pass wires thru. It's located above the brake pedal towards the e-brake. On the firewall it's between the brake booster and the throttle computer / hood hinge. I use a long philips screwdriver as an insertion tool. I tape the end of the wire I'm passing thru to the tip of the screwdriver and use the tape to blunt / cover the tip of the screwdriver as further guard against puncturing the gasket. Then it's like inserting an IV, lay the screwdriver blade against the taped bundle of wiring and slide it thru the grommet. Then get under the dash, pluck the tape off and pull the wire.

Then you've got the wire inside the vehicle and then you can just run it under the carpet edge and the pop-out door sill panels I told you about in my PM. That gets your power where you want it.

Then there's the location of the port, I have to ask why on earth you put it on top and so cockeyed? Doesn't seem wise to put a power port face up next to a drink holder. See that a lot in center console mods in the Comms forum. Accident / blown fuse waiting to happen.
The leading edge of that cargo panel, where it curves to meet the door jamb, on its vertical face should have worked nicely and been out of the way. About the midpoint just below that groove should have easily placed the internals well above the seatbelt mechanism that's located in there. But it's in now and as long as it works, I guess.
 

Martinjmpr

Wiffleball Batter
The cup holder is not a concern, as we don't ever use it (that is the cup holder for the 3rd row seat and the 3rd row seat spends all summer in the garage.) Mounting it vertically on the side of the panel was something I looked at but my concern was that I didn't want it to be blocked by either the seatbelt (if it was too far to the outside) or by any cargo I would be carrying (if too far to the inside.) I also considered mounting it on the inside of the forward "pocket" in the fender cover, my concern there was the wire from the fridge having to make a sharp bend coming out of there.
 

Forum statistics

Threads
188,132
Messages
2,902,540
Members
229,582
Latest member
JSKepler
Top