Re: Alternator not charging house batteries Reply #25 – April 08, 2020, 02:27:32 pm The fins on a isolator shows it consumes a lot of power. Makes the entire system work harder. Longer gen run time. Quote Selected
Re: Alternator not charging house batteries Reply #26 – April 08, 2020, 02:29:47 pm If the boost relay is toast, you can easily bypass it by connecting both large battery cables to the same terminal on the relay. Either side is fine. That will create a jumper around the relay and directly connect your 2 banks, which should restore charging until you get it fixed. Note that as you drain your house bank, you will also be draining your chassis batteries. Not good to leave it this way any longer than you have to. Quote Selected 1 Likes
Re: Alternator not charging house batteries Reply #27 – April 08, 2020, 02:38:46 pm I'm looking over the drawings that we have and trying to get an understanding of what all is happening. I don't really understand what each component does or how it does it. Quote Selected
Re: Alternator not charging house batteries Reply #28 – April 08, 2020, 03:04:50 pm Quote from: Chuck & Jeannie – April 08, 2020, 01:55:36 pmWith dash BOOST switch OFF, there should be no voltage at either of the small terminal posts on the BOOST solenoid.With BOOST switch ON, you should see 12 volts at one (either one - doesn't matter) of the small terminal posts on the BOOST solenoid.If you are getting 12 volts at the small solenoid post (with boost switch ON) try tapping lightly on the top of the solenoid to see if it frees up and closes (percussive persuasion). If so, it is probably corroded inside (or weak coil) and needs to be replaced.If tapping on it doesn't work, it is toast.We are getting 12v to one of the small posts on the solenoid but tapping on it didn't produce any results. On the drawings we have they show both the start and boost solenoids with only one small post instead of two. Do both small posts have the same function? And are these solenoids or relays? Everything says solenoid but they seem similar to a relay to me. Quote Selected
Re: Alternator not charging house batteries Reply #29 – April 08, 2020, 03:07:47 pm A solenoid is a type of relay.If one small terminal, the solenoid grounds by its body being connected to chassis metal If two, one small terminal is wired to ground. Quote Selected 1 Likes
Re: Alternator not charging house batteries Reply #30 – April 08, 2020, 03:09:58 pm Quote from: Caflashbob – April 08, 2020, 02:27:32 pm Longer gen run time.The isolator has nothing to do with the generator as it feeds the batteries from the main engine's alternator.Tyler,Think of the isolator as a swinging gate. If it sees one set of the batteries (whether it be coach or start) low it swings the gate open to feed that side more juice.Mike Quote Selected 1 Likes
Re: Alternator not charging house batteries Reply #31 – April 08, 2020, 03:18:47 pm Quote from: Pamela & Mike – April 08, 2020, 03:09:58 pmThe isolator has nothing to do with the generator as it feeds the batteries from the main engine's alternator.I think he was referring to the power consumed by the isolator, which means the generator has to run longer to make up for any charging that the alternator can't complete. A few seconds extra generator time on a typical charge cycle, I would imagine. In reality, I think the small amount of power wasted by the isolator just means a little (very little) extra work for the alternator. Quote Selected 1 Likes
Re: Alternator not charging house batteries Reply #32 – April 08, 2020, 03:27:55 pm bdale,What I am saying is if the system is working properly the batteries should be fully charged or close to it after you have had the engine running down the road. The voltage regulator makes up the difference in the isolator.All this discussion about mili amps really has nothing to do with helping out with the OP problem.Mike Quote Selected
Re: Alternator not charging house batteries Reply #33 – April 08, 2020, 03:35:20 pm Quote from: Pamela & Mike – April 08, 2020, 03:27:55 pmbdale, The voltage regulator makes up the difference in the isolator.MikeLet me state it a little differently. The sense wire tells the alternator the voltage on the battery side of the battery isolator. So, if the "target voltage at the battery" is 14.0 VDC, the sense wire communicates that to the alternator. The alternator must put out about 14.7 as about .7 VDC is lost to heat in the diode-based battery isolator. Quote Selected 1 Likes
Re: Alternator not charging house batteries Reply #34 – April 08, 2020, 04:29:01 pm Just out of curiosity, if someone had a decent sized solar setup could an alternator be eliminated all together? Quote Selected
Re: Alternator not charging house batteries Reply #35 – April 08, 2020, 04:31:52 pm Quote from: The Soft Boulders – April 08, 2020, 04:29:01 pmJust out of curiosity, if someone had a decent sized solar setup could an alternator be eliminated all together? NO. You would have to have a very large solar system to keep up with day time driving and ?? night driving??? Quote Selected
Topic: Alternator not charging house batteries