yotastrange Posted March 27, 2016 Share Posted March 27, 2016 I have a dual battery system mounted under the hood, passenger side is starting and driver side is coach. The system works fine, but, I want to go to one battery. I already bought a type 24 marine battery from Walwart. Question is, how to hook power to the coach.? would that be disconnecting the leads going to the coach and tying them into the truck battery posts, that would bypass the isolater, I believe. I don't think I want to hook the posts leaving the isolater that used to charge the house battery to the truck start battery.. I think that would short or "double charge" the truck battery. help appreciated, I'd like to keep the existing circuitry because I do not plan on running just the single battery for very long, I just need to get past a rough patch, the Gen quit on me and the house batt quit on me and the truck batt quit on me .. ROFL.. so I am doing this to repair the gen for now and then I plan to eventually move up into GC batts or LiIon Quote Link to comment Share on other sites More sharing options...
zero Posted March 28, 2016 Share Posted March 28, 2016 1 hour ago, yotastrange said: I have a dual battery system mounted under the hood, passenger side is starting and driver side is coach. Question is, how to hook power to the coach.? If you have a three-post isolator - all you have to to is attach all the leads to just one post. Doesn't not matter which one. Just use the post=stud to tie them all together. No such thing as "double-charge." Alternator senses voltage and cuts off at 14.2 volts. Quote Link to comment Share on other sites More sharing options...
yotastrange Posted March 28, 2016 Author Share Posted March 28, 2016 I do have a 3 terminal isolator, standing in front of vehicle looking at it from left to right there is black red and white. Black is common chassis ground, red is positive house batt and white is neg house batt. Which wires do I move and where? Tried to upload a pic got an error. After I move the wires do I put the batt on the house side after the isolator or on the truck side ? Is there a trick to uploading pics? Quote Link to comment Share on other sites More sharing options...
zero Posted March 28, 2016 Share Posted March 28, 2016 If the photos are on your computer - just hit the link at the bottom of the reply box that reads "choose files" and . . choose the files you want to post. I assume JPG or JPEGs. You stated . . " 3 terminal isolator, standing in front of vehicle looking at it from left to right there is black red and white. Black is common chassis ground, red is positive house batt and white is neg house battery. . . " That does not make sense to me. An isolator with three posts has this . . #1 post to main battery positive, #2 post to alternator positive output, and #3 post to aux battery positive. No "black to chassis ground" and no 'neg to house battery." Quote Link to comment Share on other sites More sharing options...
yotastrange Posted March 28, 2016 Author Share Posted March 28, 2016 I will get out tomorrow and look at it again, I had two batts starts the truck the other runs the cabin, but if either one is disconnected the function it performed ceases to function. I am trying to connect the new battery to the house and have it run the house and still start the engine. but...the new battery does not fit on the driver side area that is reserved for the cabin batt which would run the cabin but not start the truck... It does however fit on the passenger side which will start the truck but not run the cabin.. JD pics are on phone..That is right. I am going by colors and first glance.. after looking at them it appears the black that I thought was grounded has an insulator between the mounting block and the fender well and the other two wires I assume one goes to the start batt and the other to the house batt positive leads.. the red I think goes to house batt and the white returns to the start batt.. but if I am understanding ... the black wire is a feed wire from the alt and the white and red are feeding the batt positives for both the cabin and start batts.. so fi I want to run both the house and the truck from one battery I need to ...what connect the wire going to the start batt and house to the alt feed lug ? the one lead that would have gone to the house battery really will just hang there in the air? Quote Link to comment Share on other sites More sharing options...
yotastrange Posted March 28, 2016 Author Share Posted March 28, 2016 (edited) looking at my picture it seems the black wire is the alt line feed and is connected to the house and the isolator and something else I can't see right now. but If I disconnect the wire going to the start side and connect it to the alt feed lug it should work and I can just disconnect the house batt lead that goes to the house batt since it wont be there anymore... and that should work.. you think ? sounds good to me LOL... EDIT: ok upon further examination... black wire on left from mounting block on fender well is connected to a lead that returns to the cabin and connects to the isolator and goes to the cabin batt positive connection...., The red and white wires return to wire bundle and heads toward the alt, since I have the Toyota "star" cluster near the start batt position on the passengers side and the wire going to it is red, I am going to say the red wire goes to start batt and the white wire goes to the alt.. I will suss all that out tomorrow, but I see what you mean .. if I connect the red and white to the black that should power everything and still start the vehicle..and I can just tape up or remove the hanging house batt cable connector that would have connected to the house batt.. Edited March 28, 2016 by yotastrange I'm a dumb sh!7 Quote Link to comment Share on other sites More sharing options...
Maineah Posted March 28, 2016 Share Posted March 28, 2016 You do understand if you are using the coach lights,pump,heater etc. you run a risk of killing the battery then your truck won't start. If you are going to use just one battery all you need to do is remove one battery wire and put it on the same terminal as the other one. The isolator will have 3 heavy wires the terminals should be marked B one and two and A (alternator) if it's a 4 wire there will be a small one marked E. Remove one battery wire and land it under the other B terminal along with it's wire. Quote Link to comment Share on other sites More sharing options...
jjrbus Posted March 28, 2016 Share Posted March 28, 2016 Well you made me go look. My isolator only has 2 heavy wires, heavy being relative, looks like #8 or #6 and the small wire appears to be #14. Jim Quote Link to comment Share on other sites More sharing options...
yotastrange Posted March 28, 2016 Author Share Posted March 28, 2016 maineah yeah, I know, it isn't something I want to do, just a necessary evil atm. I was having issues with the generator (among other things) when I parked it and since I bought it, it never has had anything but automotive batteries in it (even the coach batt was auto batt). Inexperience is an unkind teacher...the coach battery failed and I have been just starting the truck occasionally, then I removed truck batt to use in another vehicle and it failed soon afterward... Now I am being forced to relocate to a place I do not yet have shore power, so I just need to get it started, drive it to my purchased property and be able to flush the toilet and test gen during repair process.... So My thinking is that if I am just flushing and trying to get gen to start I can keep it charged by starting and running the vehicle.. I have read (since I found this site awhile back) that the battery can be charged many different ways.. from shore power, or from gen on the vehicle, and even some solar stuff, which interests me, I have to do more digging when I get situated. But for now I am just trying to get everything working off a single batt so I can move and begin the troubleshooting process, all while being able to flush...not planning on using lights fridge or ac Quote Link to comment Share on other sites More sharing options...
yotastrange Posted March 28, 2016 Author Share Posted March 28, 2016 this is my isolator the wire on the left goes back to the cabin and has a battery terminal connected to one end that would have connected to the house batt, common sense would make the red wire going to the Alt and the white lead going to the starting batt.. So all I need to do is connect all 3 wires together and that will join the house and starting batts into one so then I can start the truck and run the house from just the single battery on the drivers side...? ROFLMAO.. still wont upload the picture from my computer .. maybe because it was too big in filesize? Quote Link to comment Share on other sites More sharing options...
yotastrange Posted March 28, 2016 Author Share Posted March 28, 2016 I know running one batt is frowned upon, and don't want to run just one, but in order to use two I need to swap the physical locations of the start and cabin batts locations... in the pic above the black lead coming from the firewall jumping to the isolator and then continuing on to what would be the cabin batt (however the cabin batt will not fit in that location, but will fit in the passenger side start position).. if I wanted to make that the location for the starting batt (as it will hold the tiny recommended batt for starting in this position) and assuming the red wire is in fact the ALT wire lead... If I wanted to swap the spots.. then I would only need to put the white wire on the multi lug mounted on the fenderwell and move the black battery post lead to isolator top where the white wire was..? as far as I can tell, only running the engine will charge the cabin batt, it just wont fit on the driver side location that it is wired for.. There is a tag somewhere that states the gen diodes not charge the cabin batt.. I doubt shore power will .. and I have no solar..so I have to run the truck in order to charge either battery in any case.. regardless of whether I am using one battery or dual batteries suggestions? Eventually I plan on relocating the cabin batt in the cabin and close to the distribution panel, but for now...... Quote Link to comment Share on other sites More sharing options...
yotastrange Posted March 29, 2016 Author Share Posted March 29, 2016 bump Quote Link to comment Share on other sites More sharing options...
Maineah Posted March 29, 2016 Share Posted March 29, 2016 Connect the red one to the white one. In your case I would buy a pair of alligator clips and a wire loop because most likely the post will break off if you try to remove it. The isolater is designed to charge both batteries while keeping them separated when the engine is off. That by the way is a strange mess of wires some thing you may want to look into in the future. Quote Link to comment Share on other sites More sharing options...
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