NanMWright Report post Posted February 3, 2019 Hi Folks, My house batteries will not recharge when I am driving. How do I test the isolation solenoid? Nan Share this post Link to post Share on other sites
wolfe10 Report post Posted February 3, 2019 Nan, With a solenoid-based battery isolator (as opposed to a diode-based battery isolator) you will have two large lugs and either one or two small terminals. One large lug should have chassis battery voltage all the time. When the solenoid is activated, that same voltage will be on the other large lug that goes to the house bank. If one small terminal, it will 12 VDC positive from the ignition switch (to close the solenoid). And ground would be through the metal body of the isolator to coach metal. If two small terminals, one is the 12 VDC positive (as above) and the other one is to chassis ground (likely any clean metal). So, to test: Verify chassis battery voltage at one large lug. Turn on ignition/start the engine and see if that same voltage (probably in high 13's-low 14's) now reads on the other large lug. If so all is good. If not, check for 12 VDC positive to one of the small terminals with your voltmeter ground either to the second small terminal or chassis ground if a single small terminal. If no 12 VDC to the small terminal, disconnect it and use a small jumper from the chassis battery large lug to that 12 VDC positive terminal. If large terminal voltage not the same now, solenoid is bad. If it works now, you need to find out why the ignition signal is not getting to the small positive terminal. Share this post Link to post Share on other sites
NanMWright Report post Posted February 3, 2019 Thanks, The 2-prong solenoid tests good. It has two small and two large posts. Where do I go next? Can I test the board? Share this post Link to post Share on other sites
wolfe10 Report post Posted February 4, 2019 Nan, Tell us exactly what brand/model solenoid/battery combiner you have. As soon as you mention "board", it is certainly more than a basic solenoid that combines batteries when the ignition is on and separates them when the ignition is off. Another suggestion-- go in and edit your signature to include info on your rig, That will often shorten the guessing time and give you quicker answers. Share this post Link to post Share on other sites
NanMWright Report post Posted February 6, 2019 On 2/4/2019 at 6:51 AM, wolfe10 said: Nan, Tell us exactly what brand/model solenoid/battery combiner you have. As soon as you mention "board", it is certainly more than a basic solenoid that combines batteries when the ignition is on and separates them when the ignition is off. Another suggestion-- go in and edit your signature to include info on your rig, That will often shorten the guessing time and give you quicker answers. Thank you for your response on the solenoid and panel comments. This RV is a 1999 Bounder that I have been considering swapping for my 2007 Sunseeker. I want to trade up (?) to a Class A and I've decided that this Bounder has too many problems for me to tackle. I won't work on the Bounder any more, but I will keep looking for a small Class A for a future purchase. Thank you for your time responding to my questions. Nancy Share this post Link to post Share on other sites
dickandlois Report post Posted February 7, 2019 Nancy, this is a link to a Multi-Battery Isolator PDF file that is used to connect the engine alternator to both the coach and chassis battery system. https://www.waytekwire.com/datasheet/80051.pdf The information should allow you to make charging all the batteries off the engine alternator or from a battery charger. Rich. Share this post Link to post Share on other sites
wolfe10 Report post Posted February 7, 2019 Rich, The isolator you mention is diode-based. Unless the alternator has an external sense terminal connected "downstream" of the isolator, charging voltage will be about .7 VDC LOW due to loss to heat in the diode. And, not sure how it could be used to charge from 120 VAC converter or charger. You sure wouldn't apply converter output to the center post which would back-feed the alternator. At least the only bi-directional systems I am familiar with are solenid-based, not diode-based. Share this post Link to post Share on other sites
manholt Report post Posted February 7, 2019 Nan, What length class A, year, price, make, gas or diesel, are you looking for? I have friends in the NW WA. OR and Canada. Carl Share this post Link to post Share on other sites
dickandlois Report post Posted February 7, 2019 6 hours ago, wolfe10 said: Rich, The isolator you mention is diode-based. Unless the alternator has an external sense terminal connected "downstream" of the isolator, charging voltage will be about .7 VDC LOW due to loss to heat in the diode. And, not sure how it could be used to charge from 120 VAC converter or charger. You sure wouldn't apply converter output to the center post which would back-feed the alternator. At least the only bi-directional systems I am familiar with are solenid-based, not diode-based. Brett, This is the system used on our original Fleetwood gas unit. Kind of small -with a good current level. Yes all diode systems have a .7 volt drop and the standard alternator regulator voltage is 13.5. It should not need any wire larger then a good transfer switch (ATS) Rich. See Nan mentioned that the Switch measured good, but not sure that one is mounted in the Bounder or the Sun Seeker. Share this post Link to post Share on other sites
manholt Report post Posted February 8, 2019 It has gotten confusing Rich. I agree, the board must be in Bounder...what happened to OP in ref to no charging batteries when driving? Share this post Link to post Share on other sites
wolfe10 Report post Posted February 8, 2019 From Nancy, the OP: Thank you for your response on the solenoid and panel comments. This RV is a 1999 Bounder that I have been considering swapping for my 2007 Sunseeker. I want to trade up (?) to a Class A and I've decided that this Bounder has too many problems for me to tackle. I won't work on the Bounder any more, but I will keep looking for a small Class A for a future purchase. Thank you for your time responding to my questions. Nancy Share this post Link to post Share on other sites
