Stormtyler1984dolphin Posted November 12, 2020 Share Posted November 12, 2020 Posting on here and hoping someone can help me somehow seeing as mechanics seemed to be confused about this as well. We have a 1984 Toyota Dolphin. We JUST replaced the alternator, not because it stopped working, but because it was rattling around from being so worn in where the bolts went through it that the holes were elliptical instead of round. And now the alternator isn’t feeding any power to our car battery. We replaced the wire from the back of the alternator thinking that was the issue but it did nothing. I think mechanics are confused by it having two batteries but they all keep saying that the “house” battery is charging while we’re running the engine but the car battery isn’t?? The only place the alternator attaches to is the car battery. And then there is a line that connects the two batteries together but how/ why would the house battery pull charge from the alternator and the car battery not? We had to replace the battery as we died in bumblefuck in the dark with no headlights in the rain. Quote Link to comment Share on other sites More sharing options...
Stormtyler1984dolphin Posted November 12, 2020 Author Share Posted November 12, 2020 Also 2 minutes ago, Stormtyler1984dolphin said: Posting on here and hoping someone can help me somehow seeing as mechanics seemed to be confused about this as well. We have a 1984 Toyota Dolphin. We JUST replaced the alternator, not because it stopped working, but because it was rattling around from being so worn in where the bolts went through it that the holes were elliptical instead of round. And now the alternator isn’t feeding any power to our car battery. We replaced the wire from the back of the alternator thinking that was the issue but it did nothing. I think mechanics are confused by it having two batteries but they all keep saying that the “house” battery is charging while we’re running the engine but the car battery isn’t?? The only place the alternator attaches to is the car battery. And then there is a line that connects the two batteries together but how/ why would the house battery pull charge from the alternator and the car battery not? We had to replace the battery as we died in bumblefuck in the dark with no headlights in the rain. Also we have a volt meter that’s how we knew the alternator wasn’t charging the battery. The battery was at 7 volts when we were dead on the side of the road. We have a new battery in but likely hood that it will also die eventually is very high. Quote Link to comment Share on other sites More sharing options...
linda s Posted November 12, 2020 Share Posted November 12, 2020 Use the voltmeter and check the house battery with the truck running and not running. Lets see first if the new alternator is good. Yes they can be bad right from the store. It's happened to me and I got stuck in BF too. If it's producing a charge all you can do is start replacing all of the wires. A good ground is required too. There should also be a battery isolator between the house and truck battery to protect the truck battery from being drained by the house battery when stopped and using lights or appliances. Linda S Quote Link to comment Share on other sites More sharing options...
Stormtyler1984dolphin Posted November 12, 2020 Author Share Posted November 12, 2020 2 hours ago, linda s said: Use the voltmeter and check the house battery with the truck running and not running. Lets see first if the new alternator is good. Yes they can be bad right from the store. It's happened to me and I got stuck in BF too. If it's producing a charge all you can do is start replacing all of the wires. A good ground is required too. There should also be a battery isolator between the house and truck battery to protect the truck battery from being drained by the house battery when stopped and using lights or appliances. Linda S Okay well do that tomorrow if it’s not raining too much! Quote Link to comment Share on other sites More sharing options...
Maineah Posted November 12, 2020 Share Posted November 12, 2020 It is old enough to have an external voltage regulator so it's very possible the alternator is fine and the regulator is not. Quote Link to comment Share on other sites More sharing options...
Maineah Posted November 12, 2020 Share Posted November 12, 2020 6 minutes ago, Maineah said: It is old enough to have an external voltage regulator so it's very possible the alternator is fine and the regulator is not. I also believe the alt has a fusible link in the wiring harness that supplies battery voltage to the large terminal on the alt. If I remember correctly it also had a flag on the wire with a current rating. Quote Link to comment Share on other sites More sharing options...
Stormtyler1984dolphin Posted November 12, 2020 Author Share Posted November 12, 2020 18 minutes ago, Maineah said: It is old enough to have an external voltage regulator so it's very possible the alternator is fine and the regulator is not. Okay I’ll google that and check it out Quote Link to comment Share on other sites More sharing options...
Stormtyler1984dolphin Posted November 12, 2020 Author Share Posted November 12, 2020 27 minutes ago, Maineah said: It is old enough to have an external voltage regulator so it's very possible the alternator is fine and the regulator is not. So upon a google search I realized that we do not have an external voltage regulator. The last alternator that was put it was a Chevy one wire alternator and when we replaced it we put the exact same type of Chevy one wire alternator back in. So no plug in the back of the alternator. So in theory it should work as it had worked for seemingly many years (the alternator looked like it had been there for a long while) and we hadn’t had any charging issues prior to this Quote Link to comment Share on other sites More sharing options...
WME Posted November 12, 2020 Share Posted November 12, 2020 Is your isolator a solenoid type or a diode type? A diode type is a box with fins and 3 or 4 cable studs. A solenoid type looks like an old style 35mm can with 2 big wires and 1 or 2 small wires. It is possible for a diode type to charge the house battery and fail to charge the truck battery. IN an EMERGENCY you can bolt all 3 wires to a single post and run the engine off the house battery Quote Link to comment Share on other sites More sharing options...
Stormtyler1984dolphin Posted November 12, 2020 Author Share Posted November 12, 2020 15 minutes ago, WME said: Is your isolator a solenoid type or a diode type? A diode type is a box with fins and 3 or 4 cable studs. A solenoid type looks like an old style 35mm can with 2 big wires and 1 or 2 small wires. It is possible for a diode type to charge the house battery and fail to charge the truck battery. IN an EMERGENCY you can bolt all 3 wires to a single post and run the engine off the house battery I’m fairly sure it’s a diode. Is this what you’re talking about? Quote Link to comment Share on other sites More sharing options...
Stormtyler1984dolphin Posted November 12, 2020 Author Share Posted November 12, 2020 Also we died on the side of the road at night lost all lights and we swapped the batteries to run the car off the house battery Quote Link to comment Share on other sites More sharing options...
Stormtyler1984dolphin Posted November 12, 2020 Author Share Posted November 12, 2020 This is what it looks like under the hood if it’s helpful to anyone Quote Link to comment Share on other sites More sharing options...
WME Posted November 12, 2020 Share Posted November 12, 2020 Really an Ooga horn!. Anyway you have a diode isolator, its the gold box by the clutch master cylinder. Get your volt meter and with the engine running the center post of the isolator should have 14v+ on it. Thats the alternator voltage. Less than 13 and alternator is not really good, less than 12 and its toast. If you get a bad reading check the actual output of the alternator, you could have a bad wire. The other 2 posts should have what ever voltage is on the center post - about .7v. One of those posts goes to the truck battery and the other to the house battery. So check the voltage on the posts and on the + of each battery. It should be the same. Grounds are just as important the the + leads. I also see a auto reset circuit on the house battery charge line check the voltage in both sides of it. Let us know what you find Quote Link to comment Share on other sites More sharing options...
Stormtyler1984dolphin Posted November 12, 2020 Author Share Posted November 12, 2020 5 minutes ago, WME said: Really an Ooga horn!. Anyway you have a diode isolator, its the gold box by the clutch master cylinder. Get your volt meter and with the engine running the center post of the isolator should have 14v+ on it. Thats the alternator voltage. Less than 13 and alternator is not really good, less than 12 and its toast. If you get a bad reading check the actual output of the alternator, you could have a bad wire. The other 2 posts should have what ever voltage is on the center post - about .7v. One of those posts goes to the truck battery and the other to the house battery. So check the voltage on the posts and on the + of each battery. It should be the same. Grounds are just as important the the + leads. I also see a auto reset circuit on the house battery charge line check the voltage in both sides of it. Let us know what you find Hahaha the previous owner put it in! It definitely adds character and people love it! Alrighty, it’s raining again here so once it stops we’ll fire it up and see what those spots are read. Thank you! Quote Link to comment Share on other sites More sharing options...
Stormtyler1984dolphin Posted November 12, 2020 Author Share Posted November 12, 2020 7 minutes ago, WME said: Really an Ooga horn!. Anyway you have a diode isolator, its the gold box by the clutch master cylinder. Get your volt meter and with the engine running the center post of the isolator should have 14v+ on it. Thats the alternator voltage. Less than 13 and alternator is not really good, less than 12 and its toast. If you get a bad reading check the actual output of the alternator, you could have a bad wire. The other 2 posts should have what ever voltage is on the center post - about .7v. One of those posts goes to the truck battery and the other to the house battery. So check the voltage on the posts and on the + of each battery. It should be the same. Grounds are just as important the the + leads. I also see a auto reset circuit on the house battery charge line check the voltage in both sides of it. Let us know what you find Oh actually another question. So the center post is for the alternator but there isn’t a wire that goes from the alternator to the post...should there be? The alternator is a Chevy one wire and the wire goes directly to the + lead on the car battery Quote Link to comment Share on other sites More sharing options...
Stormtyler1984dolphin Posted November 12, 2020 Author Share Posted November 12, 2020 Alright so with it running the center post reads about 12.1 and the auxiliary battery reads 15 (but we were still plugged into shore power) and the car battery side reads about 12.2 so does that mean it’s the alternator?? Quote Link to comment Share on other sites More sharing options...
WME Posted November 12, 2020 Share Posted November 12, 2020 1 hour ago, Stormtyler1984dolphin said: Oh actually another question. So the center post is for the alternator but there isn’t a wire that goes from the alternator to the post...should there be? The alternator is a Chevy one wire and the wire goes directly to the + lead on the car battery OH yes, from the alternator. The way things are now, what is the voltage on the truck battery when the engine is running? If the alternator is connected directly to the truck battery it should be charging like a normal truck no RV stuff involved...🤡stupid thought... truck battery-passenger side, house battery-drivers side. Things to check use your volt meter in the OHM function. On the isolator measure from the center terminal to one of the other posts...then reverse the leads and measure the same thing. You should have continuity in one direction and not the other (diode). Then check the center to the other post, again same thing continuity one way. Quote Link to comment Share on other sites More sharing options...
Stormtyler1984dolphin Posted November 12, 2020 Author Share Posted November 12, 2020 51 minutes ago, WME said: OH yes, from the alternator. The way things are now, what is the voltage on the truck battery when the engine is running? If the alternator is connected directly to the truck battery it should be charging like a normal truck no RV stuff involved...🤡stupid thought... truck battery-passenger side, house battery-drivers side. Things to check use your volt meter in the OHM function. On the isolator measure from the center terminal to one of the other posts...then reverse the leads and measure the same thing. You should have continuity in one direction and not the other (diode). Then check the center to the other post, again same thing continuity one way. Hm okay gotta wait for the rain to stop might wait until tomorrow to figure things out Quote Link to comment Share on other sites More sharing options...
Maineah Posted November 12, 2020 Share Posted November 12, 2020 A one wire GM alt needs a 12 volt signal to work from an external source like the key switch. Quote Link to comment Share on other sites More sharing options...
Stormtyler1984dolphin Posted November 12, 2020 Author Share Posted November 12, 2020 29 minutes ago, Maineah said: A one wire GM alt needs a 12 volt signal to work from an external source like the key switch. I’m not exactly sure what that would mean I would have to check or do Quote Link to comment Share on other sites More sharing options...
Maineah Posted November 13, 2020 Share Posted November 13, 2020 It already has a battery feed through the large wire it sits there fat dumb and happy the "onewire" is the exciter it basically kick starts the alternator. Usually it went through a warning light circuit connected to the key switch. Quote Link to comment Share on other sites More sharing options...
Stormtyler1984dolphin Posted November 13, 2020 Author Share Posted November 13, 2020 2 hours ago, Maineah said: It already has a battery feed through the large wire it sits there fat dumb and happy the "onewire" is the exciter it basically kick starts the alternator. Usually it went through a warning light circuit connected to the key switch. I’m sorry I still don’t know what that means.....there’s one wire in the back on the alternator and that one wire goes to the battery........ Quote Link to comment Share on other sites More sharing options...
WME Posted November 13, 2020 Share Posted November 13, 2020 http://www.hubbardhobbies.com/novapics/alternater-troubleshoot.htm Quote Link to comment Share on other sites More sharing options...
Stormtyler1984dolphin Posted November 14, 2020 Author Share Posted November 14, 2020 10 hours ago, WME said: http://www.hubbardhobbies.com/novapics/alternater-troubleshoot.htm This could potentially be helpful except I’m not sure we have an alternator light??? And also like I’ve said this replacement alternator that we put in is EXACTLY the same type that was previously in there with the EXACT same wiring......I would understand needing to have that wire if it had already existed but we just put everything back together the same way it was before we took it apart so in theory it should work?? Quote Link to comment Share on other sites More sharing options...
WME Posted November 14, 2020 Share Posted November 14, 2020 (edited) Just follow the diagram and check your wiring on your alternator. Broken wires do happen. Before you start trying to work on the isolator and both batteries, with the way things are hooked up you must have 14v+ on the truck battery when the engine is running. Once you get that then we can work you all the other wiring problems Edited November 14, 2020 by WME Quote Link to comment Share on other sites More sharing options...
Stormtyler1984dolphin Posted November 16, 2020 Author Share Posted November 16, 2020 On 11/13/2020 at 11:54 PM, WME said: Just follow the diagram and check your wiring on your alternator. Broken wires do happen. Before you start trying to work on the isolator and both batteries, with the way things are hooked up you must have 14v+ on the truck battery when the engine is running. Once you get that then we can work you all the other wiring problems Okay so we’ve found out that the alternator we have in there is NOT self regulating as the person that sold it to us said it was. And finding a self regulating one wire alternator has proven to be not that easy. So we bought a new alternator with the Plug that’s the same as our plug for the regulator. BUT my worry is that the old alternator wasn’t using the regulator for a reason??? Why would someone convert to a one wire self regulating alternator? So I’m wondering now if there’s a way to check the regulator before we go through all the BS of putting in the new alternator Quote Link to comment Share on other sites More sharing options...
fred heath Posted November 16, 2020 Share Posted November 16, 2020 (edited) Toyota used both a 4 wire (early) and a 5 wire (later) voltage regulator. If you have the later 5 wire regulator your alternator should have come with a short pigtail with a green end on it. Late voltage regulators are sealed electronic units and cannot be serviced. I’m sure there’s a way to test them but I never bothered. The replacement regulators are plug-n-play and not that expensive. Just buy a new regulator that matches your alternator. Will save you a lot of frustration, and you’ll know everything is new. Also, if they installed a GM single wire alternator is uses a special bracket to attach to the engine. If yes, you’ll need to find a factory Toyota bracket that works with the factory alternator. Edited November 16, 2020 by fred heath Quote Link to comment Share on other sites More sharing options...
Stormtyler1984dolphin Posted November 16, 2020 Author Share Posted November 16, 2020 5 minutes ago, fred heath said: Toyota used both a 4 wire (early) and a 5 wire (later) voltage regulator. If you have the later 5 wire regulator your alternator should have come with a short pigtail with a green end on it. Late voltage regulators are sealed electronic units and cannot be serviced. I’m sure there’s a way to test them but I never bothered. The replacement regulators are plug-n-play and not that expensive. Just buy a new regulator that matches your alternator. Will save you a lot of frustration, and you’ll know everything is new. Thank you. I’m not sure which regulator we have but now you’re making me hope that the guy at the auto parts store gave us the correct alternator lol but I guess if we replace the regulator is shouldn’t matter? God I hate that this has become such a pain in the behind. Really sucks when you live in the thing full time and are 1000 miles from the comforts and familiarity of your home town Quote Link to comment Share on other sites More sharing options...
WME Posted November 16, 2020 Share Posted November 16, 2020 This a 70 amp 1 one wire GM alternator. It uses just the battery wire, the other wires for this alternator are not used or internal. To make the dash idot light work requires adding a wire to a connector under the rubber plug https://www.jegs.com/webapp/wcs/stores/servlet/SearchResultsPageCmd?Ntt=s-10+alternator&requestYear=&storeId=10001&catalogId=10002&langId=-1&year=&make=&model=&submodel=&engine=&Nrpp=&No=&persistYmm=false. What does yours look like? Quote Link to comment Share on other sites More sharing options...
Maineah Posted November 17, 2020 Share Posted November 17, 2020 The one wire is totally regulated internally there should be only one connection the B+. If it has terminals other than the B+ they have to be connected for the alt to work. All GM alternators these days have the regulator inside some have to be excited externally if they have more than one connection. The ones with small spade connectors need an exciter wire generally from the warning light. Quote Link to comment Share on other sites More sharing options...
Stormtyler1984dolphin Posted November 17, 2020 Author Share Posted November 17, 2020 All of the words you are both saying are very hard for me to process and understand. The alternator we have in now has turned out not to be self regulating/ self excitable and therefore doesn’t work as the one wire set up we have right now. We’ve opted to try something closer to what was in there originally but only because LIVE in the rv FULL TIME and are currently parked outside of Charlotte SC (originally from Vermont and only left on our trip Nov 1) at the home of a friend of a friend of my moms. We’ve been here for a week trying to figure out how to make these things work and I can’t get parts mailed to us and continue to freeload off of these very nice people. I do not have any previous mechanical knowledge or experience and I’m apparently STUPID so all of these things you are saying I do not understand. So let me explain again and then you can explain again back to me. We do not have an alternator light in our dash so we can not have an alternator that requires us to wire it to that light as it doesn’t exist. We CAN install an alternator that is closer to the OEM with the plug in the back for the regulator HOWEVER the previous alternator that was in here was not connected to the regulator so I’m apprehensive to believe that it works SO it would be better to replace it with a single wire, self excitable, self regulating alternator but it would have to be something we could pick up in a store TOMORROW in Charleston SC. Something that requires no extra wiring as we are CLUELESS and BROKE. Quote Link to comment Share on other sites More sharing options...
Stormtyler1984dolphin Posted November 17, 2020 Author Share Posted November 17, 2020 3 hours ago, WME said: This a 70 amp 1 one wire GM alternator. It uses just the battery wire, the other wires for this alternator are not used or internal. To make the dash idot light work requires adding a wire to a connector under the rubber plug https://www.jegs.com/webapp/wcs/stores/servlet/SearchResultsPageCmd?Ntt=s-10+alternator&requestYear=&storeId=10001&catalogId=10002&langId=-1&year=&make=&model=&submodel=&engine=&Nrpp=&No=&persistYmm=false. What does yours look like? Upon looking at this Jegs website it seems that the old alternator we had in here was possibly one of these but I’m not sure if these alternators are universal or what the deal is Quote Link to comment Share on other sites More sharing options...
Stormtyler1984dolphin Posted November 17, 2020 Author Share Posted November 17, 2020 10 minutes ago, Stormtyler1984dolphin said: Upon looking at this Jegs website it seems that the old alternator we had in here was possibly one of these but I’m not sure if these alternators are universal or what the deal is This looks almost identical to the one we used to have but I’m not sure how to know if it’ll work. I can have it same day shipped but it would be a lot of money wasted if it won’t work Quote Link to comment Share on other sites More sharing options...
WME Posted November 17, 2020 Share Posted November 17, 2020 Wow long distance and you don't speak electron. 🤔 Buying by mail in this type of situation by mail can be scary. Don't give up, we'll keep trying. Here is an O'Reilly Auto Parts version, if the local parts store doesn't have this exact one maybe they can cross it to one they do have... https://www.oreillyauto.com/detail/b/wilson-5289/charging---starting-16772/alternator-11425/f7cab2ae3cc0/wilson-61-amp-alternator/90013125/4826752?q=gm+one+wire+alternator&pos=0 Two ideas, take the alternator you have to a parts store that can test it, see if it works. Can you take a good picture of the back side of the alternator you have? If you need it a jumper connector is less than $10. ALL older Toyota pickups have a charge light or an amp meter, with a factory setup the light comes on until the engine starts. Can you get a flash light and shine it on the instrument cluster. Look for a word like charge/alternator/battery or maybe its a battery picture Quote Link to comment Share on other sites More sharing options...
linda s Posted November 17, 2020 Share Posted November 17, 2020 Is there any reason for him to not buy a Toyota alternator? Lots of aftermarket ones. I've had an aftermarket one in mine from Autozone that's a decade old. Still works fine Linda S Quote Link to comment Share on other sites More sharing options...
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