Auxiliary battery hook up help

[Bohemian scout]

I want to make sure I get this right. I unhooked my auxiliary battery to install a floor,.I'm hooking it back up and also want to connect a 12 volt plug to charge my fridge with the auxiliary battery. These pics show what I have, I'm not sure where to hook in the 12v plug. I'm not sure what the small red/black wires are for, isolator?  The person who installed it said he would hook the battery directly to my 12volt plug shown in pic but I asked a mechanic to check, he said it wasn't.  Feel free to ask questions. I don't know what I'm doing but trying...can you help?

 

[Bohemian scout]

The 2nd pic is of the battery before I uninstalled it.

 

[XERTYX]

Based on what I'm seeing the larger red and black wires I would assume are connected to the charging method.

The smaller red and black wires I would also assume go to power other loads.

The 12v cigarette plug (I think that's what you're connecting) I would connect to the bolts on the sides of the battery terminals.

Normally red is positive and black is negative for DC connections.

Those ring terminals on the adapter you're installing I would ratchet down onto bolts on the main battery terminal connectors.

Assuming everything was wired correctly red to red black to black.

 

[XERTYX]

Also, as a matter of curiosity what exactly is the charging method for that AGM? (Pics) battery?

Like solar? Household plugin? Generator? Engine?

Does the 12v ciggy plug in pic 1 run off of this battery? Is this a Dodge vehicle?

 

[highdesertranger]

Yes your plug can connect directly to the battery pos and neg as there is a fuse in the system. I have no idea where the smaller red/black wires go but it to needs a fuse and it looks like a poor crimp. also that terminal on the large red wire is about the worse one you can have. See I just made more work for you aren't you happy, LOL. Highdesertranger

 

[Happy Camper]

also that terminal on the large red wire is about the worse one you can have.  See I just made more work for you aren't you happy,  LOL.  Highdesertranger

 You're a giver

Good advice

 

[XERTYX]

Sorry, I noticed the positive lug just had a compression fitting with untinned wire. I forgot that part. I'm a big believer in if it ain't broke dont fix it, but that is a very very valid point.

 

[XERTYX]

Btw the reason I asked if it was a dodge is because someone working on a budget could very easily connect the starting and house batteries. I doubt it would stand the test of time... but I can foresee a caravan being wired functionally but very poorly for super cheap by "some dude".

And I dont know what you're working with.... so that's why.

 

[Bohemian scout]

The dude that sold me the wrong kind of battery also installed an isolator. He claimed he was the king of 12 volt turns out he was a meth head.
This is a 2006 FordE150 passenger Van. I Assume the auxiliary battery gets charged by the main vehicle battery and there's an isolator under the hood very hard to see but I tried to take a few pics.
I'm thinking the Thinner red and black wires were his attempt to wire my 12v cigarette lighter plug to that battery so I could plug my refrigerator into that plug and the power would come from the auxiliary battery not the main battery. I don't think it worked because when I plugged my fridge in for several days at a time without my Suitcase solar connected to the auxiliary battery my Van's battery would get run down. The auxiliary battery supposedly charges when I drive and when I hook up my suitcase solar. I ordered the 12 V adapter to hook up to my aux battery so I could plug my refrigerator Into it .

 

[Bohemian scout]

Isolator

 

[XERTYX]

My first thought is that the fuse block like the dodge does has a fuse that has 2 positions. Always on auxiliary sockets, or ignition only auxiliary.

If the 12v outlet was wired to the AGM house battery in theory it would provide 10A of charging current to the house battery.

This would allow the house battery to run loads, and appear to function perfectly until it suddenly DIDNT.

 

[Bohemian scout]

Pics

 

[XERTYX]

Ah. So it does have alternator charging. Ok then. That one connects to the alternator I believe. That's above my pay grade.

I dont wanna screw anything up.

 

[Bohemian scout]

Photo of where the wires come up through the floor

 

[Bohemian scout]

Ok so what if I don't reconnect the small wires, Can II cap them off some way, would it be dangerous If they are just left there until I can figure out what theyre connected to?
Is the terminal on the black heavy wire correct? Do I need to replace the red it with one like that? Do I need to disconnect the main Van battery when I do this?

 

[Bohemian scout]

Ok so what if I don't reconnect the small wires, Can II cap them off some way, would it be dangerous If they are just left there until I can figure out what theyre connected to?
Is the terminal on the black heavy wire correct? Do I need to replace the red it with one like that? Do I need to disconnect the main Van battery when I do this?

 

[highdesertranger]

We don't know where the smaller wires go so it is impossible to say what happens if you don't connect them.

The terminal on the ground/negative/black wire looks ok from here.

Some one with a meter should be able to get to the bottom of all this pretty fast. What general area are you in? Maybe someone can give you a hand. I will if you are close by.

Highdesertranger

 

[bullfrog]

Quiet the mess you have there. As long as the vehicle is turned off there should be no power coming through the large red wire as it should run from the isolator to the house battery positive post. Once it is connected to the house battery positive post and the house battery is grounded to the frame it will have power, so be careful not to short it out. I normally use military spec battery terminals as they are made to be used with battery cables with lug (large eyelet) terminals. It appears a chassis ground was used for your house battery negative circuit. Which if I were doing it would be the large black wire attached to the negative post of the house battery and the other end possibly bolted through the eye terminal on the other end of the large black wire to a bare metal surface of the frame of the vehicle. Any smaller red wires attached to the positive post of the battery should be fused as close as possible to their connection at the positive post of the house battery. the smaller black wires should be attached to the negative post of the house battery negative terminal. Do you have and know how to use a multimeter? Do you know how to and have the tools to properly crimp lug terminals? If not learn or go to an automotive electrical shop and get the work done. Search this site as this has been discussed here before. My guess is the small black and red wires go to the aftermarket ciggy plug in the panel above. This can easily be verified with a multimeter. I would not connect anything that I had not verified and would tape them off until I did. Hope this helps.

 

[Bohemian scout]

I have a multi meter that I use to check my batteries. I'm not sure how to check other things or what setting to use but want to learn.. When the small wires were connected to the battery I plugged my fridge into the 12volt (cig lt) and it worked fine while driving for several years. It even worked fine sitting for a.few.days when I couldn't set up solar. Sometimes it would drain my starter battery then I realized my fridge setting was suppose to be.set on high not low. This had to do with how much drain it would put on main battery when the auxiliary battery got too low. Took me a while to figure that out!
When I bought a new battery I asked for them to check out all the wiring concerning the battery system. He said he didn't think the aux battery was hooked up to the cigarette lighter. I didn't get to talk to the mechanic directly because of covid. How can I check that?

 

[Bohemian scout]

I live in Oregon on the Columbia River east of Hood River at the dalles. I would be willing to drive to get help. I've also been wanting to find help taking the charge controller off my renogy 100 watt suitcase solar, moving it inside so I can mount my solar panel on my roof rack.