AbleThought Posted November 29, 2016 Share Posted November 29, 2016 Hi all, i believe by duel battery isolator has kicked the bucket. I get zero volts from either side posts. Center post gets altinator 14.5 ish volts. I've had to hook my battery up to center post to charge it. Two questions.. 1 does this sound like a dead isolator to you? 2 O Reilly's has a duel battery isolator in stock (image and specs attached) will this one work? If not what should I be looking for? thanks so much Quote Link to comment Share on other sites More sharing options...
WME Posted November 29, 2016 Share Posted November 29, 2016 Where do all the wires go?? Did it ever work?? A standard setup is 3 wires. Alternator center. house battery one side and truck battery other side. Some isolators need an "exciter" voltage. Quote Link to comment Share on other sites More sharing options...
AbleThought Posted November 29, 2016 Author Share Posted November 29, 2016 8 minutes ago, WME said: Where do all the wires go?? Did it ever work?? A standard setup is 3 wires. Alternator center. house battery one side and truck battery other side. Some isolators need an "exciter" voltage. The wires go exactly like you said. Post on left side of pic goes to the coach battery. post to the right goes to the cab battery. Center post is the altinator. The extra wire on center post is a cable I had to run to the center post to charge cab battery as it was not charging and there is a dead wire in factory wiring. It had a inline fuse near battery terminal. it did work at one point. I had a spout of electrical problems a while back and has not worked since then. I've had to bypass to get by. My original issue was a faulty voltage regulator. if I revert back to factory wiring I get left and right sides no voltage. Center post altinator voltage(about 14.5) Quote Link to comment Share on other sites More sharing options...
AbleThought Posted November 29, 2016 Author Share Posted November 29, 2016 16 minutes ago, WME said: Where do all the wires go?? Did it ever work?? A standard setup is 3 wires. Alternator center. house battery one side and truck battery other side. Some isolators need an "exciter" voltage. At the very least I'm getting it at Oreillys which will take it back as a return if I still have the same issue but I'm not sure if it's ok for my truck. I it's rated for 70amps and i only need 30 so I would think it's ok but I don't really know much about them tbh other than it is supposed to charge two batteries Quote Link to comment Share on other sites More sharing options...
WME Posted November 29, 2016 Share Posted November 29, 2016 OK try the new one. There 2 wires on the house battery post, are you charging 2 house battery's?. Quote Link to comment Share on other sites More sharing options...
AbleThought Posted November 29, 2016 Author Share Posted November 29, 2016 39 minutes ago, WME said: OK try the new one. There 2 wires on the house battery post, are you charging 2 house battery's?. Nope how it's wired in mine is positive battery post to circuit breaker to left isolator post to circuit breaker to coach... is that not right? I have been struggling with this since I bought the truck... it always seems off so I wouldn't be surprised if it's wrong. I attached a pic with diagram in blue Quote Link to comment Share on other sites More sharing options...
WME Posted November 30, 2016 Share Posted November 30, 2016 Weird. But electrically its OK. With the engine off, you should have coach battery v on the isolated terminal with the" blue" wire. Check both sides of the cb. Most units are setup with the coach connected directly to the battery and only one wire from the isolator to the battery. Electrically you are sort of the same. With the engine off, check for v on both sides of the " blue" wire cb. You should have house battery v (12 v). Check the battery too. Quote Link to comment Share on other sites More sharing options...
AbleThought Posted December 2, 2016 Author Share Posted December 2, 2016 On 11/29/2016 at 6:40 PM, WME said: Weird. But electrically its OK. With the engine off, you should have coach battery v on the isolated terminal with the" blue" wire. Check both sides of the cb. Most units are setup with the coach connected directly to the battery and only one wire from the isolator to the battery. Electrically you are sort of the same. With the engine off, check for v on both sides of the " blue" wire cb. You should have house battery v (12 v). Check the battery too. New isolator got the batteries charging. I get about 15v at center post. 14.07 at driving battery 14.3-14.5 at coach battery.. that sound normal? Quote Link to comment Share on other sites More sharing options...
WME Posted December 2, 2016 Share Posted December 2, 2016 Close to normal. I would still rerig the wiring so the coach is hooked directly to the battery. The long wire will cause a voltage drop. It might be just enough to keep the heater from starting with a 50% battery. Quote Link to comment Share on other sites More sharing options...
AbleThought Posted December 2, 2016 Author Share Posted December 2, 2016 6 minutes ago, WME said: Close to normal. I would still rerig the wiring so the coach is hooked directly to the battery. The long wire will cause a voltage drop. It might be just enough to keep the heater from starting with a 50% battery. Ok so coach straight to battery then wire from isolator to battery... where do the breakers come in? One in between coach and battery and one in between isolator post and battery? Quote Link to comment Share on other sites More sharing options...
WME Posted December 2, 2016 Share Posted December 2, 2016 Yep CB from battery to coach and a CB from isolator to battery Quote Link to comment Share on other sites More sharing options...
Maineah Posted December 2, 2016 Share Posted December 2, 2016 There is something really funky there. There are way too many wires. The center terminal should only have one wire and each battery terminal should only have one. The #2 terminal goes where? (The one with the shrink wrap). Your drawing shows both wires going to the coach I think one goes to the truck battery this means it is no longer an isolator. Find out where the second wire from the center terminal goes I'm guessing the truck battery. Here is what I think happened the isolator went south someone by passed it with the added wiring not having a clue how it worked so right now it's nothing more than a terminal block. It is common practice to use breakers in line that's normal but not to the same battery connection. Now this is where it might get interesting your truck may need a 4 terminal isolator and the only reason it works at all is because the second wire on the center terminal goes to the truck battery. Generally the alternators with internal regulators needed the 4th wire the ones with an external regulator did not. Find out where everything goes first no guessing allowed. Quote Link to comment Share on other sites More sharing options...
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