Friday, September 14, 2012

Battery Is Charging Now

I arrived at my friends house around 11:30 am, he wasn't home from work yet so proceeded to start cleaning all my connections to my house battery.
The Isolator?
I popped the hood of the van and attacked this little contraption.  Is it the isolator?  Is that the right terminology?  I know it is the link between the van battery and the house battery and it was pretty cruddy so l cleaned and polished up the connectors.  I only got one little shock when l leaned against the van, it was more of a tickle, but it got me to stop leaning against the van when l was unscrewing the bolts. 
The next step for me was to take the back box off the van so l could gain access to the house battery that is under my teeny tiny closet.  I cleaned those connectors also.
Next on the list was to take off the little cardboard door l had made (it's temporary until l get a piece of wood cut next week for it) to stop the cats from exploring another hole in the vans walls.  Behind this wall is this fuse (below)
Close up
Not so close
The fuse was blown.  That was the problem with the battery not charging.  Once l replaced it (yes, l have spare fuses in the van's tool box) the battery showed hope.
The friend showed up from work after l had solved the mystery and as l was loading the box back on the van.
I plugged in at my friends for a couple of hours, while l helped him do some finishing touches on his home before he moves into it on Saturday (yep, l'm helping him with that).
 I'm happy to report that all my house lights worked fine when l went to battery power before l left.


  1. Hi Tammy:
    Nice to see that you found the problem!
    Yes you are right, that black box with the fins is the isolator.

    On the isolator the middle wire goes to the alternator on your engine, the wire on the right (in the picture) goes to your RV battery and the 2 wires on the left connect to the engine battery wiring harness.

    The red wire on the right then goes to an electrical breaker (like a fuse that resets itself automatically unless it is busted). A bad breaker can also stop your RV battery from charging.

    Now for the purpose of my post, you mentioned feeling some tingles when you worked on the battery isolator. I would remove the negative also called the ground wire (-)(usually black) from both the engine battery and the RV battery.

    Your engine battery connector will probably need a 1/2 inch wrench. I don't know what size wrench your RV battery will need, probably uses a wing nut that will allow you to use a small adjustable wrench.

    Leaving batteries connected while working on wires can lead to big sparks and in extreme cases maybe a fire or a melted wire.

    There is usually no need to disconnect the red (+) positive wire but if you want to remove it be sure to remove the negative (ground) wire first and replace the negative wire last when everything else is connected properly.

    If you are still at your friends place I would measure the voltage at each of the battery posts and at the right and left posts on the battery isolator. With the batteries connected and the engine running the voltage should be around 13V - 13.8V(ideal) - 14V at all of the above locations.

    The center post on the battery isolator should be around 14V - 14.8V - 15V , about 1V higher than the voltage at the batteries.

    Please let us know if the voltages that you measure are not in this range.

    With moving fan blades and belts under the hood please be really careful, if you are at all in doubt just measure the voltages with the engine off, both the outside posts on the battery isolator should be above 12V with fully charged batteries.

    Testing with the engine running is the best way to check if the battery isolator is working properly.

    At least the weather is still nice.

    1. Oh My Goodness OffRoad, thank you so much for taking the time to explain all the wires for me. I will head by to the friends this week (hopefully) and test all the volts as you suggested.

      Thanks Again!!!!!

    2. Hopefully I am wrong but I have a nagging feeling that you may not have solved your house battery charging problem hence the need to take some measurements.

      That 'tingling feeling' you had may have been the fuse blowing.

      I hope that I am wrong but either way, no big deal, an inverter is less than $100 at Princess Auto not sure of the price at CTC. The small breaker is less than $20 and you can replace these things yourself but I want to wait for the measurements, everything may be just perfect again.

      OffRoadCruiser (Carl)

    3. Sorry, I meant 'battery isolator' not 'inverter'.

      A digital multimeter is less than $20 on sale and a valuable addition for any RV owners tool box.


    4. Carl, l can 't Thank you enough for all your help. I will have my laptop opened to all the hints you have told me over the last couple of weeks and figure out this house of mine. Thank you so much!

  2. Congrats! Never doubted you for a second! :) You are such an inspiration.

    "I only got one little shock, ... it was more a tickle..." Gotta say it again - You. Are. Amazing! :)

    1. Thanks Deb! You are the same as me...totally capable!!!!