I am having some difficulty getting my house battery in my 1992 Ford E350 Class C Four Winds to charge properly. I think the solenoid between the engine battery and house battery is failing. On the engine battery side of the solenoid, with the engine running, I get a 12.7 volt reading with my tester, with the positive tester lead on the solenoid post and negative lead on the engine negative battery post.On the house battery side of the solenoid, with the negative lead on the engine negative battery post and the positive lead on the post on the house battery side of the solenoid, I get an 11.7 reading.With my Onan generator running, I get a 13.8 reading at the engine battery and engine battery side of the solenoid, and an 11.8 reading at the house battery side of the solenoid.Does this mean my solenoid is failing? Both batteries are brand new.I am in Europe and it may be difficult to find an appropriate soleinod. Can I bypass the solenoid to get my battery to charge until I find the proper replacement part if I need one?ThaNks.

Yes but a casual reader might ask--How do you start a generator when you are in Europe?

Well, I push the button on it and it starts. It is mounted on the vehicle. Is that answering you question? And does that yes you posted mean I can bypass like I am thinking? Thanks again.

mdecorso wrote:Well, I push the button on it and it starts. It is mounted on the vehicle. Is that answering you question? And does that yes you posted mean I can bypass like I am thinking? Thanks again.Yes, you can bypass the solenoid. My curiosity was about the distances but now that you've explained that your arm reaches from Europe to Alaska, I'm all good.

First you must find out if the control voltage of the solenoid is there before you throw the baby out with the bath water.Of course you can bypass the solenoid. Just pile up the big wires on one side or the other.Before doing that check the small terminals on the solenoid. You should be getting 12 volts on one and zero on the other. This is the control voltage. If you have a blown fuse somewhere the voltage might not be there.

This doesn't make sense. When the Onan is running, you should be getting more than 11.8V at the house battery.mdecorso wrote:With my Onan generator running, I get a 13.8 reading at the engine battery and engine battery side of the solenoid, and an 11.8 reading at the house battery side of the solenoid.ThaNks.

House battery not charging properly. Bypass solenoid?

YC_1
Nomad
Nov 13, 2015
Wolfe is on the trail. You have bad connections. Ditto on the solenoid only needing one small terminal. However, make sure you clean the mount where it is bolted in place because that is the ground connection,.
Salvo
Explorer
Nov 13, 2015
That still doesn't make any sense.

With engine off, and gen on, you get 13+V at the chassis (car) battery and only 11.8V at the house battery? Sounds to me you have chassis and house battery mixed up. Instead of measuring at the solenoid, measure directly at the chassis and house batteries.
Get solid measurements.

Is this how your solenoid looks?

If it is then you're in luck. Disconnect both chassis and house batteries ground and remove solenoid. Take a hacksaw and cut the aluminum cover just below the electrical connections all the way around. Don't cut deep, just the cover. Now you can see the contacts that need cleaning. Get some fine sand paper to remove the pitting. Duct tape the cover back on and install. I've done this, it works.

mdecorso wrote:
With generator on I am getting 13+ at the car battery, and then fluctuations of 11.82 to 12.04 at the house battery.
Sam_Spade
Explorer
Nov 14, 2015
mdecorso wrote:
I get the same voltage reading coming off of that, 12.7.

I sorta need the battery to charge NOW or I can't start the generator

You are missing out on a critical point:
With no voltage readings above 12.7 present, NOTHING will be charging very much or at all regardless of what you do.

You should be able to start the generator with another vehicle battery and jumper cables but you might have to leave them connected for a few minutes before starting.

I have a STRONG urge to comment on "shipping" an RV to Europe.....but that's a subject for a different thread.
Sam_Spade
Explorer
Nov 14, 2015
mdecorso wrote:
With generator on I am getting 13+ at the car battery, and then fluctuations of 11.82 to 12.04 at the house battery.

I think this means that your house batteries are DEAD and you don't have a good connection at or near them somewhere.

In order to get things back to a workable situation you may HAVE to charge your house batteries with an external charger somehow to be sure that they will take and hold a charge.
RJsfishin
Explorer
Nov 14, 2015
I wouldn't turn a hacksaw to anything. I would find the problem. You have a bad/poor connection somewhere. Once you find the problem, the solenoid will more than likely be fine.
You need 12v power now ??? Jumper the 2 batteries together, and you will have power to the house.
Harvey51
Explorer
Nov 15, 2015
Easy to tell if a poor connection or wire is dropping the voltage - disconnect the charging wire from the house battery. With no current flowing, a resistance will not cause a voltage drop between the solenoid and the end of the disconnected wire. Connect again and a drop in voltage indicates current flowing through a resistance between the measuring points. Could be in ground connections.

Looks like alternator trouble to me, too. I would put a voltmeter across the engine battery and watch while someone starts the engine. The voltage should initially be well over 14 for a few minutes.
Salvo
Explorer
Nov 15, 2015
There shouldn't be any speculation whether solenoid is bad. Place voltmeter probes across the two big lugs of the solenoid.

With engine off, voltage will be greater than 1V. Depending on which probe goes where, measurement may be greater than -1V.

With engine running, voltage will be less than 1V. If voltage is greater than 1V then solenoid is bad.

Forum Discussion

House battery not charging properly. Bypass solenoid?

About Technical Issues

Related Content

Battery disconnect solenoid

winterized properly?

Solenoid Question

HWH 325 solenoid fuse blew

Battery Disconnect Solenoid