Switchable Dual Batteries

[Matt G]

yawl need to know...about five years ago when Matt accosted me at the Binder Bee for some "help", he didn't know which way to turn the key to start a Scout II!

Wait a sec... scouts actually start???

thanks for the props kimosabe - it's all about quality instruction from binder u! Your tuition rates stinkin' rule too, btw. now that my daughter helped me rebuild the mercury carb (that little motor screams now!) it's an intractable, full-on family thang.

Best deal on the ladyfolk end of things is to show them how useful all this old garbage iron can be! About 6 months after installing my dual batteries (which my dear wife thought was a total waste of time, but she encouraged me anyway 'cause she knows what "wrench therapy" means) the oem battery in her honda accord croaks at a gas station in a driving rainstorm. She's stranded and in danger of missing a dr. Appointment, so she calls me in a mild panic. I rush over to the station, pull the dead lead out of the honda, rip my optima red top crank battery out of the Scout & drop it in the honda, then relocate my aux battery and re-fire the Scout sans problema. The honda fires right up, she looks at me like I'm a stinkin' genius, makes her dr. Appointment on time, and promises me she'll never complain about my dual battery setup again!

thanks for the info on working out the aux battery once in a while. I never do that but I should, and I know enough about batteries that I shoulda' figured that out on my own. Oh well, maybe this old napa aux battery will die soon and I can put another red top in there.

 

[ronmc1954]

Well I thought I would post my dual battery install (copied from Matt) looks the same as Matt's but I wanted to show the battery tray I made. It is as solid as a rock.

Ron

 

[blueblur1984]

I noticed a lot of guys use isolators, but is it necessary to get a diode style and a selonoid style like in the op's photos or can I get away with just the diode style? Also if anybody can recommend a cheap place to get 2 gauge wiring I would really appreciate it!

Update: nevermind! I see what the solonoid is for now! I found a great diagram that dumbs this down enough even for me. The bottom of page 2.



http://www.surepower.com/pdf/180012q.pdf

 

[Michael Mayben]

Using an isolator is far more modern and technically advanced than using the relays as we did back in the 50's and 60's.

The isolator blocks can take unlimited lifetime cycles of use, the relays have a calculated duty cycle just like a battery. And they are an electromechanical component that is subject to failure at any time.

I source 2 gauge battery cable at any local auto supply. Both in bulk on spools (sold by the foot) or in pre-terminated cables hanging on the wall in 6" incremental lengths.

 

[blueblur1984]

So a year and a half later I finally get around to the dual battery set up. I could really use some advice from some guys who have done it before. I've had a few configurations ranging from nothing when I turn the ignition to starting and being unable to shut it off (even after pulling the battery terminals). I have a rough diagram of how it's set up now along with photos. I used to have a two gauge wire from the positive post of the alternator to the left post on the new solenoid but removed it thinking that the common post on the switch would juice it enough. Anybody see any glaring errors?

Ps it's a 72 IH Scout with a 345 and a tf727

 

[ronmc1954]

Give me some time I will see if I can make a wiring diagram tonight. It's hard to tell by your pics, just from a glance thought somethings not quite right. If not tonight tomorrow for sure.
Hopefully someone else will chime in to speed things up, times a little short tonight. Sorry
ron

 

[ronmc1954]

In the mean time look at the picture of your solinoid and compare it to Matt's solinoid pic. There is a definate difference. Also there is a post on here for installing a remote solinoid you might look that over.
http://www.forums.IHPartsAmerica.com/electrical-tech/3170-electrical-system-upgrade-remote-starter-relay-installation.html

Ron

 

[blueblur1984]

Thanks for the link ron. I was doing a little more trouble shooting tonight and it's definitely the way I've got the solenoid wired up. This thing has the worst case of po I've ever seen...the wiring going from the alternator to where it originally met the starter had been splice three times. Each time a different color and guage of wire had been used. It's a miracle the thing ever worked.

Long story short I need to trace all the wires from end to end and replace the entire length with some fresh copper. I'll do a little more homework and report back.

 

[ronmc1954]

Taking a closer look at your solenoid, it looks like you have what looks to be a 10ga wire connected to one of the smaller posts on the solenoid. The two small posts on the solenoid are the coil part of the solenoid. One is the keyed "start" from the ignition and the other is just a ground. That activates the solenoid.
The 2 large posts are battery/starter connections. One would be bat+ from the bat switch and the other goes to the starter. The bat + wire is also where the 10ga alt wire goes.

Ron

 

[ronmc1954]

Ignore my last post,I was wrong
here is my remote solenoid wiring diagram:

If you have anything left of the oem wiring this should work. Without tearing my loom apart this is the best I got, see if this helps, post back if it does not.
Ron

 

[Craig]

Ron can you draw in your alternator too. Are you running a battery isolator too?

 

[blueblur1984]

ignore my last post,I was wrong
here is my remote solenoid wiring diagram:

If you have anything left of the oem wiring this should work. Without tearing my loom apart this is the best I got, see if this helps, post back if it does not.
Ron

Thanks! This is tremendously helpful but unfortunately I'm working with a pretty severe case of po. The wires going to the coil were so badly damaged I wound up replacing the green and white wires that were there with a new 16 gauge yellow and blue wire (what I had on hand). The wires look similar but I'm not 100% positive if anybody knows exactly what those should be.

After clearing out some wiring that dead ended (missing accessories?) and removing some heat shrink here is what I'm looking at. I had (originally) three white wires, two green wires, the blue 10 gauge, the 2 gauge going to the common post on the switch and another 2 guage to the starter motor. The two white wires that go to the cab I connected to the "s" post, the white and green wires (now replaced by blue and yellow) met with a red wire and connected to the coil. The blue 10 gauge I connected to the left post (after realizing the ignition wouldn't work without it) and I didn't have the green wire to the alternator connected. This allowed the ignition to work properly and the vehicle to start, but the idle sounded terrible!

So down to the brass tax. It sounds ike the green alternator wire is supposed to hook up on the same post as the blue 10 gauge, but is there anything else that seems to be missing? The copper post is getting really beat up from all the different variations I've tried so I'd like to make this next attempt my last one. Thanks for all the support and I'll keep slugging away at cleaning up the rats nest under the hood.

 

[Craig]

I was looking at my wiring and I found a green wire. In fact there all green. is there a number on your green wire?

 

[ronmc1954]

thanks! This is tremendously helpful but unfortunately I'm working with a pretty severe case of po. The wires going to the coil were so badly damaged I wound up replacing the green and white wires that were there with a new 16 gauge yellow and blue wire (what I had on hand). The wires look similar but I'm not 100% positive if anybody knows exactly what those should be.

After clearing out some wiring that dead ended (missing accessories?) and removing some heat shrink here is what I'm looking at. I had (originally) three white wires, two green wires, the blue 10 gauge, the 2 gauge going to the common post on the switch and another 2 guage to the starter motor. The two white wires that go to the cab I connected to the "s" post, the white and green wires (now replaced by blue and yellow) met with a red wire and connected to the coil. The blue 10 gauge I connected to the left post (after realizing the ignition wouldn't work without it) and I didn't have the green wire to the alternator connected. This allowed the ignition to work properly and the vehicle to start, but the idle sounded terrible!

So down to the brass tax. It sounds ike the green alternator wire is supposed to hook up on the same post as the blue 10 gauge, but is there anything else that seems to be missing? The copper post is getting really beat up from all the different variations I've tried so I'd like to make this next attempt my last one. Thanks for all the support and I'll keep slugging away at cleaning up the rats nest under the hood.

Ok let start with:

It sounds ike the green alternator wire is supposed to hook up on the same post as the blue 10 gauge

I pretty sure your right, that same post also has bat + coming from bat switch.

I guess I am going to have to cut into my harness to verify that green wire my eye sight is not what it used to be and neither is the wire numbers for that matter.
Blurblur can you explain whitch side of your solenoid is the starter side, I can't tell from the pic, it makes a difference on my preception of what I am looking at.

I do see what looks like 2 wires on the solenoid small post where your white wire is. Looks black, that post only needs a system ground which should be white. You can verify with a volt meter.

I am going to have to cut into my harness to be more detailed but then it May not be what you have under your hood with the po virus you describe. If you were here it would be no problem.

Give me untill this weekend I will see if I can come up with a complete diagram, but you need to figure how to put it in your truck I can't sort through the po virus from here, sorry.

Craig, I will include the isolator in that to, although the surefire instructions have a good drawing too.

I will be back when I have a little more time, I know you what to get it done, I know how you feel.

Ron

 

[blueblur1984]

Absolutely no rush ron. I bought a marine grade 12 circuit fuse panel so pulling out all the accesories and re-routing them was in the plan anyway. I'm thinking the more I pick through the more clear what my solenoid issue is should be. My buddy is also coming up to give me a hand too so as I figure things out I'll post. Thanks so much again ron.

Edit:

"blurblur can you explain whitch side of your solenoid is the starter side, I can't tell from the pic, it makes a difference on my preception of what I am looking at."

sure thing. As you're facing the solenoid:

left post: this has the 2 guage wire going to the common post on the marine switch, the blue 10 guage that goes to the bulkhead (I'm assuming that meets up with the blue 10 gauge at the alternator somewhere) and now the green wire that comes directly from the alternator.

Middle left post: all I have here is the two white wires that go to the bulkhead (and I assume the ignition). There is a third white wire that goes to the coil...maybe I should swap that in and one of the others out?

Middle right post: here I have a blue and yellow wire. This used to be a white wire and a green wire but they were in really bad shape so I flat out replaced them. Both of these along with another red wire go to the coil.

Right post: all I have here is a 2 gauge black wire that goes to the starter. The starter is bridged like it should be.

Again, it starts, runs, and turns off with the ignition switch like it's supposed to. The only problem is the idle sounds like there is some serious misfiring going on. I'm guessing it has to due with the wiring around the coil?

 

[blueblur1984]

I've got it running like it's supposed to! It was actually a simple fix. The issue was that I had two white wires on the middle left post, and one white and one green on the middle right. I noticed that the diameter of two of the white wires were the same so I paired the matching white wires with the green wire on the middle right post and left the thicker white wire on the middle left post. Now everything works the way it should.

Thanks for the help guys and best of luck on your own projects!

 

[ronmc1954]

Glad to here that blueblur! It's a good feeling getting it to work and you have the confidence of not needing a jump. Are you planning a winch install also?
Ron

 

[blueblur1984]

Actually ron it came with an older model 6k warn winch...in fact it had electrical goodies ranging from an onboard air compressor, aux lights, power seat, sound system. I'm sure there's more that I'm not remembering. All of it along with the ignition were running off of one deep cycle marine battery, and they had used the speaker amp as a fuse box to run the accessories

so within the first few weeks I replaced the battery to get the cold cranking amps I was looking for and removed everything else not necessary to run the truck. Now I'm picking through hoping to get all the cool accessories I hacked out wired up and running properly.

Speaking of running properly I could use some more advice. I have been driving the Scout on and off the last couple of weeks and last night I notice my alternator was smoking. After putting it out I drove home and noticed my alt gauge was bottomed out (ie no charge) and by the time I got home my headlights were getting dim. I think it's the original alternator and from what my friends figured it was just the alt not being able to handle the juice. I'm skeptical because whether it's battery 1, 2 or both the meter still reads 12v, but they were convinced this was the culprit. Either way I need a new alternator but I'm hoping to get some advice before burning up another perfectly good part.

 

[ronmc1954]

Well without an alternator there is not much to test other than the batteries, charge them up and have them tested either a good parts store or gas station that still does service work. They can bring the tester right out to the Scout and test.
But when you get an alternator you can test the charging circuit, starting with batt voltage with the Scout off then again with it running and check both batteries that way.
You should see 12.5vdc without the truck running and approx. 14.5vdc with it running, again you should see it on both batts.
Also your stock amp gauge should read just like normal when you batt switch is in the stock or batt a position, but if you switch to batt b you dash amp guage will show some discharge but the stock amp guage does not work in the batt b position.
You can do amp readings also but you will need a volt meter that reads dc amps.

Now having said all that did you notice any over-charging before the alt started smoking? I have seen my system go it to an over charging situation just a couple of times since I install the dual batt system. As near as I can tell it is the batt isolator sticking (for a lack of a better term) when it happens I turn the batt switch to off and ground the posts on the isolator just for a second, turn every thing back on and its fine. Just fyi and my install was back in 2010 so this issue has not been a big concern, but I do watch my amp guage a little more than I used to.

Ron

 

[blueblur1984]

I tried testing the batteries with a multimeter when I first installed and they were running within normal vdc parameters. During the drive I noticed the alternator gauge's needle was bottomed out to the left and the battery was slowly being drained, but this was about 15-20 minutes in. I pulled the alternator and brought it to my local kragen yesterday where they bench tested it and it seems to be dead.

I didn't explicitly notice over charging but I didn't notice the problem until after I had been driving for awhile. The only thing I can think of is that I screwed up and was running both batteries the entire drive. Normally I only do that if it's having a tough start and then switch to one. While it runs around 12vdc on both batteries the amperage May have been more than the tired old alternator could handle.

Now that I know I have to replace it I May as well upgrade...hopefully my issue is the dual battery set up demanding more amperage than the alternator could handle. Of course kragen only had 37-68 amp models (which I think they had 70 from the factory?) but they were able to recommend a place in town that rebuilds alternators to better than stock specs. Thanks again for the help and I'll report back once I know more...hopefully by the time this is all squared away the electrical will the most solid feature of the truck.

 

[ronmc1954]

I didn't explicitly notice over charging but I didn't notice the problem until after I had been driving for awhile. The only thing I can think of is that I screwed up and was running both batteries the entire drive. Normally I only do that if it's having a tough start and then switch to one. While it runs around 12vdc on both batteries the amperage May have been more than the tired old alternator could handle.

Running with both batt's should not have caused the problem. With a battery isolator both batteries are always being charged. The isolator prevents the system from from drawing the charge from one batt to the other when switching.
If I were to have a starting problem and I pulled my engine batt down, then switched to both batts the dead battery can not pull power out of you winch batt. It prevents the inrush of current from one battery to the other which can cause battery damage.
As I said the alternator is always charging both batteries no matter where your batt switch is set. I have had not problems running off of the stock 63amp alternator with my system.

Ron