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Randall, RVIA Certification
Category: RV
Satisfied Customers: 11925
Experience:  RVDA/RVIA Master Certified Technician with many years experience.
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House lights work when connected to chassis battery but not

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house lights work when connected to chassis battery but not when connected to house battery. all batteries are charged
JA: Just to clarify, what are the exact lights you're talking about?
Customer: the 12 volt house ceiling lights
JA: Are you fixing your Volt yourself? What have you tried so far?
Customer: checked all breakers. ran engine to charge all batteries. checked voltage on all batteries. with lights on, I've switched th aux switch from off to on. when the aux switch is on, the lights burn. when aux switch is off, the lights don't burn
JA: Anything else you want the mechanic to know before I connect you?
Customer: the chassie battery has 12.6 volts, the house batteries have 13.4 volts. the house lights worlk on shore power but fail whe shore power is off
Customer: replied 1 year ago.
RV is a 2006 Winnebago 34A
Customer: replied 1 year ago.
Lights work on chassis battery or shore power but not on house batteries

Hi! My name is ***** ***** I can assist you with this. I may need some additional information from you first in order to give a complete answer.

This sounds like one of two things. Either the disconnect solenoid isn't working and the house batteries aren't on and in the loop (most probable) OR the house batteries are not viable. Any that are over 3 years old are suspect and should be load tested to see. Dirty cables on the house batteries, especially the ground lead could do this as well. Start there and then get back to me if we need to go further or do some testing. A small digital multimeter is very helpful for this sort of testing and those are about $20 or so at most hardware stores and easy to use. All follow ups are included in our fee and fully expected.

Customer: replied 1 year ago.
Have cleaned terminals. No change in result. I'm standing by with multi meter

Sorry for the delay........I have a shop and Mondays can be a zoo! Take your meter and see what kind of DC volts you have going INTO and OUT OF the disconnect solenoid for the house batteries. That is the unit that makes that distinct "click" when you hit the disconenct switch. Check the fuse(s) on there as it may be a blown fuse and just not working. The voltage should be the same on both sides.

You need to take that cover off where is says "Battery Mode and Relays" and the disconnect solenoid is on the right. Test between a ground and the large cable on each side. Set the meter on 20 VDC.

Customer: replied 1 year ago.
The solenoid is obscured by the fuse panel inside the case. Is there a way to test it without removing the fuse panel?

Not really, unless you can get to the start of those leads so you don't have to take that loose. If you do, disconnect the negative lead first on the batteries and then pull that fuse panel forward and out of the way and put something in there to keep it from shorting out and then reconnnect the cable and test.

Customer: replied 1 year ago.
Voltage is 12.88 on both sides of solenoid

Is that with you plugged into shore power or not?

I think you mentioned that you had over 13 VDC at the batteries before?

Customer: replied 1 year ago.
Not plugged into shore power. House battery has 13.08 volts

What do you read when it is plugged into shore power? Do each side.

Customer: replied 1 year ago.
13.10 left
13,70 right

So you have .6 VDC difference and that is a fair amount. I am wondering if those contacts are burned. One way you can tell here is to add a jumper or move one side to the other and see if the lights work that way. If so, you know that the solenoid is bad or failing.

Customer: replied 1 year ago.
How do you install a jumper?

It can be a wire with an alligator clip on each end or a wire with a ring terminal on each end that fits the post on the solenoid OR just move one side over to the other side to see if that restores power.

How old are the house batteries? I am wondering if they are opening up inside when any load it applied.

Customer: replied 1 year ago.
With a jumper across the six switch, the lights burn with the switch in either position

Then that pretty much shows that the switch is not making good contact inside. Replacing it should fix this.

Customer: replied 1 year ago.
The batteries are probably several years old. Would you recommend replacing them or the solenoid first? Thanks for the overtime

Have them load tested to see if they are good or failing. And you are welcome! Some questions just take more time to sort out. Please take the time to enter in a rating as that is the only way I get credit from the site for the time I spent assisting you here.

Customer: replied 1 year ago.
I've had batteries load tested. OK.
Checked ground with ohm meter. Good. There are 2 sole pods or relays behind the fuse panel. Which one should be replaced?

The one you jumped across to get the lights to work............

Customer: replied 1 year ago.
Ok, the reason I asked is that you originally asked me to jumper the device on the right side. After I got batteries disconnected so that the fuse panel could be pulled back, I realized that there are 2 relays and the one I tested is to the left. The other one is actually closer to the Aux Batterry switch in the doorway. I just wanted to eliminate any confusion.

As far as I can tell, the battery aux start switch is on the left and has no fuses on it.

Customer: replied 1 year ago.
When I started to remove the solenoid I discovered that one of the nuts on the right side was loose. I tightened it and reconnected the batteries. Now I still have similar voltage on both sides of the solenoid but the lights don't come on when I jumper across it

But you did before?

Customer: replied 1 year ago.

Are you sure you have good contact from one of the large posts to the other large post? If you aren't using a large enough gauge wire you may burn it up.

Customer: replied 1 year ago.
I have already removed the solenoid and ordered an exact replacement. I'll contact you after installing the replacement. Thanks

O.K...........I think that will resolve this.

Customer: replied 1 year ago.
Today I replaced the battery isolation solenoid and the symptoms are unchanged. House lights work On chassis battery or shore power but not on fully charged house batteries

Take a look at the attached link for the Aux start solenoid (on the left) and the Battery disconnect solenoid (on the right) and tell me which one you replaced. And then if the one on the right, what is the DC voltage on each side of the solenoid with shore power plugged in.

Customer: replied 1 year ago.
The link offered leads only to a page warning of possibility of shock plus 2 blank (total of 3) pages. Please resend the link. The part I replaced was a trombetta part #936-1215-022-21. The other relay, located to the right has a fuse attached to it and the word "relay" printed on it

That one on the right is the disconnect solenoid and would be the one connecting the house batteries to the system. Isn't that the one you jumped before to get the lights to work?

That link opens all three pages on my side..........

Customer: replied 1 year ago.
I've tried that link on 3 different computers with same result. Can you send me a screen shot of the image which you are referring too. I have replaced the solenoid to the left which I believe is consistent with your suggestion. The one I replace I believe to be the battery isolation solenoid. Did you intend for me to replace the relay located on the right which has a fuse located on top of it?

Actually, if you re-read my posts you should see that the disconnect solenoid is the one with the fuse on the right. That is the one I thought you were jumping. You can get that set of diagrams by going to the following link and opening up the page for "Chassis Electrical Box" and get this.

Customer: replied 1 year ago.
I get the same result when I select this link. It must be an issue with my internet connection. To be clear, did you suggest that I replace the device on the left or right?

The one on the right with the fuse and probably made by Intellitec. Be sure that it isn't just a blown fuse.

Customer: replied 1 year ago.
Ok, I tried to get it clear. I'll replace the one on the right tomorrow. Thanks

You are most welcome.........and sorry for the confusion on this.

Customer: replied 1 year ago.
I have the relay out. Should there be 2 fuses on top. Unit has plug for 2 fuses but mine only has 1 fuse. Fuse block or plug on right has a fuse and a wire connected to it. One on left has no fuse or wire connected to it. Both fuse blocks are connected with a bare wire to the adjacent copper lug. Want to eliminate other problem before I buy another $60 part
Customer: replied 1 year ago.
Sorry the plug on the left side has the fuse
Customer: replied 1 year ago.
a wire connected

Some applications only use one fuse, so don't worry about the lack of the other one.

Customer: replied 1 year ago.
I have replaced the battery disconnect relay. The symptoms are the same. House lights work when connected to chassis batteries. But not when connected to house battery

Are you sure you got it wired up and turned back on? You have to reset the switch. You told me before when you jumped over that you have lights. If this is wired up right and new and in the correct position it has to work as long as the batteries are good. Does it "click" when you hit the switch?

Customer: replied 12 months ago.
it clicks on and off
Customer: replied 12 months ago.
I wired it back just like it was. I took photos before to make sure I got it back right
Customer: replied 12 months ago.
How do you reset the switch?

Just go in and hit it for "Use" on the position. If it clicks, it is working. Try the jumper again across the larger cables on each side and see if the lights work again.

Customer: replied 12 months ago.
My switch does not have "use" on it. It says "AUX BATT" on the switch and "ON" or "OFF". The house lights work only when "ON" is selected.

So when it is clicked to "On" they work? If so, then it is working fine.

So is it working now or not?

Customer: replied 12 months ago.
Apparently there was never anything wrong

You just had the switch in the wrong position? Please take the time to enter in a rating as that is the only way I get credit from the site for the time spent assisting you here. Thanks!

Customer: replied 12 months ago.
I'm trying to decide how much "help" you have been. I've replaced a solenoid and a relay based on your advice that didn't need to be replaced. Over $100 plus extremely painful work in extremely tight spaces. How much help do you think you have been?

Not sure my fault that you didn't test the relay correctly. My direction was correct IF that had been bad. Guess you have to decide that. You can always sell the parts or keep them for spares. Maybe just a good learning lesson here.

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