tofubiscuit Posted July 31, 2014 Share Posted July 31, 2014 Looked at my fuse box, converter panel yesterday for the first time, and this note is taped inside (note the date - 1995). I know absolutely nothing about electrical systems. Does this mean my interior lights, etc. are running off my engine battery? That would explain why my engine battery died yesterday. Picture of battery is my coach battery compartment - looks like a normal engine battery. Shouldn't there be some deep cycle marine battery there. Quote Link to comment Share on other sites More sharing options...
linda s Posted July 31, 2014 Share Posted July 31, 2014 Yeah that looks messed up. I'm not an electrical person either but since your supposed to have several fuses I wonder why the 15 amp fuse they say it's all on doesn't keep blowing. I think just the water pump is supposed to have a 20 amp fuse. Yes your supposed to have a deep cycle battery back there for the coach but seems like nothing is hooked up to it. Look under you hood and see if you can find your isolater. Looks like this and mounted on firewall inside engine compartment. Should be wires attached to all 4 poles. Look to for anything that looks jury rigged on your engine battery. Linda S isolater http://www.carid.com/tekonsha-trailer-hitches/tekonsha-breakaway-kits-3727158.html Quote Link to comment Share on other sites More sharing options...
Derek up North Posted July 31, 2014 Share Posted July 31, 2014 ... but seems like nothing is hooked up to it. Yes, that looks like a 'Universal' car battery with both top and the cursed GM side mounts. I see 1 wire (large) connected to each side terminal. Anyone's guess where they go. Quote Link to comment Share on other sites More sharing options...
linda s Posted July 31, 2014 Share Posted July 31, 2014 I didn't mean I didn't see anything hooked up to it. I meant according to the note nothing is hooked up to it. I do see wires there, I just don't have anyway to know what's hooked to what. Hope someone with a Sunrader who knows more about electrical than me joins in here. You might need to find someone to help you track these wires and install them correctly Linda S Quote Link to comment Share on other sites More sharing options...
Derek up North Posted July 31, 2014 Share Posted July 31, 2014 I don't think it's a Sunrader owner you're looking for. Those are DPO 'improvements'. I think you're looking for anyone who knows how to use a multimeter. Quote Link to comment Share on other sites More sharing options...
linda s Posted July 31, 2014 Share Posted July 31, 2014 Yes she needs help in person. Only way to track down what was done and put it back correctly Linda S Quote Link to comment Share on other sites More sharing options...
tofubiscuit Posted July 31, 2014 Author Share Posted July 31, 2014 I don't know what I am looking at, but here are some pictures from under my hood. Crap, I guess I found my first major issue. I know someone in town who is an electrician and can do all his own automotive work, he'd probably be cheaper than any rv place. Want to eventually attach solar panels in a few months. Was going to use the empty generator area for the batteries. Maybe should get all the work done at once, instead of fixing a problem twice. Quote Link to comment Share on other sites More sharing options...
zero Posted July 31, 2014 Share Posted July 31, 2014 Looked at my fuse box, converter panel yesterday for the first time, and this note is taped inside (note the date - 1995). I know absolutely nothing about electrical systems. Does this mean my interior lights, etc. are running off my engine battery? That would explain why my engine battery died yesterday. Picture of battery is my coach battery compartment - looks like a normal engine battery. Shouldn't there be some deep cycle marine battery there. Since the battery has a 65 month warranty - it must be just a car battery. You'd be hard pressed to find a 2 year warranty on any deep-cycle battery and many are only 1 year. That note isn't very specific. Having a 15 amp circuit "under the hood" doesn't tell us much. Obviously the water pump and refrigerator cannot both be hooked to a single 15 amp circuit. Water pump can draw 6 amps. Refrigerator 8 amps (if a 3-way). Fan around 4 amps. Propane furnace 8-12 amps. I see a self-resetting circuit breaker next to your battery. Where does that go? Quote Link to comment Share on other sites More sharing options...
zero Posted July 31, 2014 Share Posted July 31, 2014 I think "#1 you need to find out where your power-control center is getting it's main DC power from. It should be wired to some soft of battery separator so you can drain your "house" battery without draining your starting battery. #2 You need to ascertain that all the RV appliances and lights are hooked up to that power-control center and not your starting battery. #3 you ought to get a deep cycle battery for the back although a car battery WILL work. Just not as well. #4 you need to find out what you have for a device that keeps your battery system separated from your starting system when the engine is not running. Quote Link to comment Share on other sites More sharing options...
linda s Posted July 31, 2014 Share Posted July 31, 2014 I don't know what I am looking at, but here are some pictures from under my hood. Crap, I guess I found my first major issue. I know someone in town who is an electrician and can do all his own automotive work, he'd probably be cheaper than any rv place. Want to eventually attach solar panels in a few months. Was going to use the empty generator area for the batteries. Maybe should get all the work done at once, instead of fixing a problem twice. Look inside the engine compartment directly opposite your drivers seat. That's where my isolater is mounted and yours should be the same. We could at least see if it's hooked up. Power from alternator goes through isolater and then to engine battery and coach battery. 4th pole is for the ground Linda S Quote Link to comment Share on other sites More sharing options...
tofubiscuit Posted July 31, 2014 Author Share Posted July 31, 2014 Unfortunately I see nothing that looks like an isolator mounted anywhere. Here are pictures if you can make things out. I'm guessing what is mounted on passenger side is the wiper motor? Certainly an isolator is in there somewhere - wouldn't this have come from the factory wired correctly and then someone over the years has messed with it. The odd thing is how meticulous past owners were with records and receipts. Maybe this thing fell into the wrong hands for a few years. Besides wanting this fixed properly my main concern was I was going to go up to DC and Baltimore for 2 weeks starting next week. I wasn't planning on going into campgrounds and hooking up, but... Maybe that is why this wasn't an issue for past owners. The people I bought this from always stayed in campgrounds and hooked up to power. I hooked up to power at a campground for 2 days about 2 months ago - frig and all ran fine. Parked here at home my frig is running off propane and I have an electrical cord coming through a window powering a lamp, so I'm not really using the rv electrical system - but it is obviously still pulling power from my engine battery since that went dead yesterday. Quote Link to comment Share on other sites More sharing options...
WME Posted July 31, 2014 Share Posted July 31, 2014 The isolator is the blue finned box by the brake booster. AND it is supposed to have 3 wires on it!!! So I guess the note is right. Quote Link to comment Share on other sites More sharing options...
tofubiscuit Posted July 31, 2014 Author Share Posted July 31, 2014 I was wondering what that funky looking thing was! Quote Link to comment Share on other sites More sharing options...
zero Posted July 31, 2014 Share Posted July 31, 2014 I was wondering what that funky looking thing was! The item I marked #1 is a self-resetting circuit breaker. Take a look at it and see how many amps it is rated. I'm wondering how your rig is wired at the moment. Originally - the post I marked #3 would get all the power coming from the alternator. charge current would then come out both terminals #2 and #3. #2 goes to one battery and #3 to the other. The idea is that both batteries get charged but one battery cannot draw power from the other battery. That due to rectifiers that work like one-way check-valves. That circuit breaker is in an odd location. Assuming all the charge current is passing through it - it needs to be something like a 60-70 amp breaker. From the photo it looks a lot smaller. I'm wondering if that was originally the breaker only for the charge current going to the house battery and now it's carrying ALL 60 amps of potential charge current. Quote Link to comment Share on other sites More sharing options...
WME Posted July 31, 2014 Share Posted July 31, 2014 This thing is a mess and trying to fix it via the web site could lead to problems If you look at the first set of pics in the first post, there seems to be an auto breaker mounted next to the battery. 2 breakers in the charge line seems wrong. Quote Link to comment Share on other sites More sharing options...
linda s Posted July 31, 2014 Share Posted July 31, 2014 That circuit breaker on the firewall is a 30 amp breaker. I have one just like it but my isolater is on the firewall next to it. Circuit breaker is attached to engine battery wires. That's the way I got it so when I changed the isolater I didn't change them. Coach battery wires won't reach to that side anyway Linda S Quote Link to comment Share on other sites More sharing options...
zero Posted August 1, 2014 Share Posted August 1, 2014 That circuit breaker on the firewall is a 30 amp breaker. I have one just like it but my isolater is on the firewall next to it. Circuit breaker is attached to engine battery wires. That's the way I got it so when I changed the isolater I didn't change them. Coach battery wires won't reach to that side anyway Linda S Something does not make sense . . at least not to me. When that rectifier-based isolator was originally wired - all output from the alternator went to one post (the input post). On the two output posts - one gets wired to the starting battery with NO circuit breaker unless it exceeds the alternator capacity that is 60 amps. The second output post gets wired to the "house" battery and if it uses 10 gauge wire- the circuit breaker should be 30 amps or less. Much depends on the total capacity of the isolator. Right now - it appears that all alternator output is wired through that single circuit breaker. The alternator is rated 14 volts @ 60 amps. That kind of current cannot pass through a 30 amp breaker more then a few seconds. Normally with OEM wiring - a circuit breaker is never used in the main alternator charge wire. A fusible link is often used instead that matches the alternator output. Quote Link to comment Share on other sites More sharing options...
zero Posted August 1, 2014 Share Posted August 1, 2014 Here's what Toyota uses OEM with the standard 60 amp alternator . A 80 amp fusible line is used in the alternator output wire. That wire is 6 or 8 gauge (I forget). Hooking up that wire into a 10 gauge wire with a 30 amp breaker can not work correctly. Here is how my Minicruiser is wired. Just one way of many to wire things up. Alternator output has the OEM Toyota 80 amp fusible link. I have that circuit running to a continuous-duty relay. I have that relay on the fender-well rated for 150 amps continuous. It is energized by a voltage-sensing module. When the starting battery gets fully charged - the relay automatically closes and puts the rear "house" batteries into the system. The output the the starting battery is with 8 gauge wire an no fuse or circuit breaker. The wiring to the rear "house" batteries is #2 gauge and wired through a 60 amp manually resetting circuit breaker. Actually there two of those breakers. One at each end of that #2 AWG charge wire. Quote Link to comment Share on other sites More sharing options...
zero Posted August 1, 2014 Share Posted August 1, 2014 Here's a better photo of the setup I'm using with annotations. Quote Link to comment Share on other sites More sharing options...
WME Posted August 2, 2014 Share Posted August 2, 2014 Well Tofu you got 3 choices 1. Find a RV repair shop and tell them to fix your 12v setup, be sure to bring $200. 2. Camp in campgrounds like the PO did. 3. Get a volt meter and a book and fix it your self. Starting level book. http://www.amazon.com/Electrical-Systems-Troubleshooting-Repairing-Improvement/dp/007042778X/ref=la_B001ITVMYK_1_2?s=books&ie=UTF8&qid=1406938352&sr=1-2 You might as well start with #3. With a 25 year old RV having a voltmeter and knowing how to use it is as important as having tools. Quote Link to comment Share on other sites More sharing options...
tofubiscuit Posted August 2, 2014 Author Share Posted August 2, 2014 It is getting more and more mysterious. Took out the engine battery, it is totally dead and wouldn't take a jump. My interior coach lights worked. The note says it's all hooked up under hood, which then shouldn't work with no engine battery. No wire going from isolator to coach battery. Found a disconnected wire near coach battery that I started tracing to see if it is supposed to go to isolator. Had to stop, started pouring rain. When it clears up I'll just start tracing all the wires. Everything hooked up to fuses under hood looks factory, so I'm still trying to figure out out what is powering what. On my trip next week I guess I'll just have to stay places I can hook up. Quote Link to comment Share on other sites More sharing options...
tofubiscuit Posted August 2, 2014 Author Share Posted August 2, 2014 And thanks for the book suggestion. My collection of repair books is quickly expanding. I'm getting the hang of it though. All the various systems are becoming less and less daunting as I research them. Quote Link to comment Share on other sites More sharing options...
Derek up North Posted August 2, 2014 Share Posted August 2, 2014 This sounds like a classic FUBAR. I believe we're dealing with a Sunrader here? Does anyone have a good wiring diagram online of the Sunrader factory wiring? If I was in this situation, I'd concentrate on returning everything to 'original' and get rid of the DPO's 'Original' ideas!! Even if it meant disconnecting everything and carefully adding back in one circuit at a time! I hate electrics and hate even more working on electrics without a decent wiring diagram!! Quote Link to comment Share on other sites More sharing options...
tofubiscuit Posted August 2, 2014 Author Share Posted August 2, 2014 The good news is that by the end of this I will be an expert on sunrader systems. Hooking up the solar will be a breeze! Quote Link to comment Share on other sites More sharing options...
zero Posted August 2, 2014 Share Posted August 2, 2014 . Found a disconnected wire near coach battery that I started tracing to see if it is supposed to go to isolator. You've got a circuit breaker right next to your "house" battery. What is that hooked up to? Quote Link to comment Share on other sites More sharing options...
zero Posted August 2, 2014 Share Posted August 2, 2014 Here's a Sunrader diagram. Obviously not the way your rig is wired right now. There should be NO circuit breaker in main alternator output lead unless it's bigger then 60 amps. Toyota uses 80 amps. Quote Link to comment Share on other sites More sharing options...
tofubiscuit Posted August 3, 2014 Author Share Posted August 3, 2014 Thanks for the diagram. Have to take a day off from the sunrader to deal with my paying job. Tomorrow I'll be back home to deal with more wiring - hopefully weather will dry out by then. Next step will be to trace all the wiring, and find out what is powering interior coach lights and water pump. They still work with no engine battery. Before I took it out engine battery was still hooked up through isolator, but coach battery isn't. For some reason whoever felt the need to bypass the isolator. I'll test it to see if it even works properly. Quote Link to comment Share on other sites More sharing options...
zero Posted August 3, 2014 Share Posted August 3, 2014 I don't want to confuse things further, but . . . You ought to trace the big wire that comes from the alternator and figure out where it is going. It's probably #6 gauge. When your RV was new - that wire went directly to that blue isolater. I don't see how that i possible now. If your Toyota was just a bare truck - that alternator wire would go directly to the battery with an 80 amp fusible-link in the line for protection. When these trucks were made into RVs - that alternator wire was redirected to the middle post of that isolator (on most brands of isolators). Then one side would continue on to the starting battery with no fuse or breaker. The other post would often be hooked to a 30 amp circuit-breaker and then on to the coach battery. The isolator diagram attached is for a four-post unit. Many older RVs only have three post versions like you seem to have in your photo. Wiring is the same minus the extra 14 gauge wire shown. Quote Link to comment Share on other sites More sharing options...
Maineah Posted August 3, 2014 Share Posted August 3, 2014 No matter how they wired it, it cannot work. Your truck requires a 4 wire isolator and modification to the alternator wiring. It looks like what they were trying to do is use the isolator as a block the only problem the current flow would allow the coach battery to charge but would not stop it from discharging the truck battery because as the coach battery discharged the truck battery would try to charge it until they were equal. Now in order to charge both, the truck battery would have to be connected to the terminal on the isolator where there is no connection and I'm going to guess the center wire does not go to the alternator but to the truck battery. I believe they removed a relay type isolator and put the solid state isolator in place because they thought it would work because after all it is an isolator. One sure way to find out would be to remove the center wire and see if it has power with the engine off. In your case I hope it does because the fix is as simple as installing a relay. Quote Link to comment Share on other sites More sharing options...
tofubiscuit Posted August 4, 2014 Author Share Posted August 4, 2014 Thanks, when I get home tomorrow afternoon I'll trace the wires and see what happens if I disconnect. That is, of course, once I put a new engine battery in. The old one is out seeing if it can get charged, but I'm just going to get a new one regardless. Quote Link to comment Share on other sites More sharing options...
tofubiscuit Posted August 4, 2014 Author Share Posted August 4, 2014 Also, should I get a relay type isolator? If that is what I am supposed to have I would like to put the rig back to best operating procedure. May as well put it all in correctly since I'm apparently about to do a major extricate overhaul. My long term goal with the sunrader is to live in it around the country boondocking, so it is worth it to replace whatever I have to to make it long term road worthy. Quote Link to comment Share on other sites More sharing options...
WME Posted August 4, 2014 Share Posted August 4, 2014 A diode isolator will have a .7v drop across it. A relay type will have much less when new, or has high quality contacts (silver) Quote Link to comment Share on other sites More sharing options...
linda s Posted August 4, 2014 Share Posted August 4, 2014 A diode isolator will have a .7v drop across it. A relay type will have much less when new, or has high quality contacts (silver)She's new to RV's and electric stuff. I know when I need something I really appreciate when you guys post links of what and exactly where I can get it. Linda S Quote Link to comment Share on other sites More sharing options...
zero Posted August 4, 2014 Share Posted August 4, 2014 The RV being discussed came new with a rectifier-based "isolator." Note that all these devices are used to "separate" or "isolate" batteries when the "house" battery is being used. Also used to "combine" batteries when the alternator is charging. That being said - the marketing terms like "isolator" and "separate" often refer to two different types of devices. "Isolator" is usually a solid-state device using rectifiers and no moving parts. Like the Sunrader came new with. "Separators" are usually relays with moving parts and often automatically controlled. Both are easy to install. http://www.waytekwire.com/item/77053/BATTERY-ISOLATOR-90-AMP/ http://www.waytekwire.com/item/80046/SURE-POWER-702-MULTI-BATTERY/\ http://www.waytekwire.com/item/80079/SURE-POWER-702R-MULTI-BATTERY/ http://www.waytekwire.com/item/80000/SURE-POWER-1314-A-BATTERY/ http://www.powerstream.com/battery-isolator.htm Quote Link to comment Share on other sites More sharing options...
Maineah Posted August 4, 2014 Share Posted August 4, 2014 First lets find out if my guess is correct it's a little hard to see it from here. If it is the fix is simple and cheap the relay needs to be continuous duty designed for RV use most auto parts stores and on line sellers will have them. If there is a trusted shop in your neighbor hood or an RV shop they should be able to check it out for you in short order. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.