Class C House Battery Not Charging on Engine

[CarolynRose]

Hi,

I have a 1993 Class C Jamboree on a Ford E350 Chassis. I've been living in it about 4 months and at first the house battery was charging when I drove, but all of a sudden it stopped. It does charge when I run the generator and I think it still charges if I plug into AC (it's been a while).  

It's a brand new battery, I just replaced the old one about 2 months ago. It's a deep cycle marine battery. 

I was plugging in about once a week to charge it but have been boondocking for about 3 weeks and I'm having trouble keeping it fully charged. Like I said, it used to be that all I had to do was drive for a few hours and it would be fine. But now I have to run the generator a couple hours a day. 

Has anyone had any experience with this and know what the problem could be? Any ideas would be appreciated. 
Thanks!

 

[highdesertranger]

somewhere there is a battery isolator/solenoid. it's either gone bad or it's not getting a signal from the ignition to charge the house battery. I will try to find some pictures so you know what to look for. highdesertranger

 

[highdesertranger]

here's some pics.


this is your typical isolator.


this is your typical solenoid.  there are other types but these are your most common.

here's your basic 2 battery set up.

hope this helps.  if you could locate the isolator/solenoid we can help you troubleshoot it.  highdesertranger

 

[CarolynRose]

here's some pics.


this is your typical isolator.


this is your typical solenoid.  there are other types but these are your most common.

here's your basic 2 battery set up.

hope this helps.  if you could locate the isolator/solenoid we can help you troubleshoot it.  highdesertranger

Thank you for this! 

I took some pics of what I think are these same parts.  What I think is the isolator is very hard to get to to snap a good pic, I hope these help. 
Thanks again.

 

[highdesertranger]

it the first 2 the third is the ignition module. in the first picture you can see 2 large wires connected to the top. they should be hot all the time. if you disconnect the positive on the house battery only one should be hot. that is your feed(line) the other is your charge wire for the house battery(load). the 2 small wires on the bottom, one is you energizing wire that causes the solenoid to connect the 2 large terminals. this wir should be hot with the engine running. test it make sur it gets hot. if it doesn't you probably have a blown fuse. if it does get hot disconnect the load wire and see if its hot with the engine running if it's not your solenoid is bad. let us know what you find and if you need more help. highdesertranger

 

[Gary68]

i would start by getting all those connections shinny and clean,disconnect batteries then take them apart and hit them with some sandpaper,then check fuse,then get a multimeter or find someone with one and do what hdr says

 

[SternWake]

The first pic makes it appear as if Somebody previously ran a jumper across the solenoid/ contactor. That red U shaped wire, if it goes between the two bigger studs is a bypass, likely installed because the solenoid was not being activated or had otherwise failed.

If so, there has been no battery isolation with engine off.

The wires and contacts are looking in bad condition.

Put digital multimeter ground on engine battery with engine running and put positive probe on both of those two bigger bolts. They should read the same with engine running and not the same with engine not running, if it were operating properly.

Fuses on these large wires to and from the solenoid is recommended, but often ignored by installers. Do follow these bigger wires from solenoid to either engine battery or alternator (+) stud. There very well might not be an inline fuse.

Also the house batteries could be grounded directly to frame. Follow the (-) wire from house battery (-) to frame. These frame grounds are very problematic and are likely in way worse condition than the connections in your photos. YOu must remove the bolt holding it to frame, and make shiny, and retighten. You cannot visually call it good, or bad. But if it looks like it is white and crusty, it is likely bad.

 

[CarolynRose]

it the first 2 the third is the ignition module.  in the first picture you can see 2 large wires connected to the top.  they should be hot all the time.  if you disconnect the positive on the house battery only one should be hot.  that is your feed(line) the other is your charge wire for the house battery(load).  the 2 small wires on the bottom,  one is you energizing wire that causes the solenoid to connect the 2 large terminals.  this wir should be hot with the engine running.  test it make sur it gets hot.  if it doesn't you probably have a blown fuse. if it does get hot disconnect the load wire and see if its hot with the engine running if it's not your solenoid is bad.  let us know what you find and if you need more help.  highdesertranger

 

[CarolynRose]

Thank you all so much for your help. I followed your advice and checked the connections with the Voltmeter and there is a charge going into the Solenoid from the engine battery, but not out to the house battery (the reading is the same on the house battery connection from solenoid with engine running and not). There is also no inline fuse on any of the cables running from it. I was able to pull out the engine battery to get a better look at the solenoid and cables, but I couldn't get the house battery connection off the solenoid to do further testing, the nut just kept turning the nut next to the solenoid and I couldn't get in there with any of my tools to keep it stable while trying to wrench it off. (what a pain!). 

My guess, from your help and the tests, is that the solenoid is bad. Unfortunately I'll have to take it to a shop to have it changed because I can't get the darn nuts off! .

At least I know what it is. All of your advice and suggestions were very helpful. Thank you!!! - Carolyn