Battery not charging

[silverloaf]

tony-bare -

I have a 1988 30P. I recently went through the 12v wiring at the front of the trailer. This included replacing the 7-pin wiring harness to the tow vehicle. I have a wiring diagram in the trailer owners manual.

I don't know how yours follows the wiring diagram. But here is the way my trailer is set up.

Underneath the trailer at the front is a pocket with a cover plate. Removing the cover plate exposes all the wiring running to and from the battery as well as 7-pin wiring harness to the tow vehicle.

The only exception is the electric jack. It is connected directly to the positive (+) side of the battery. There should be a 30 amp in-line fuse between the jack and battery. The jack gets its ground through the trailer frame.

There should be only one wire running from the battery to the pocket. It is 8 gauge and has a 40 amp in-line fuse. Once in the pocket, it is joined with a heavy wire leading to the kill switch and the black wire from the 7-pin harness. You will also find a number of white (ground) wires running from the pocket to the minus (-) side of the battery.

With 12v kill switch off and the 110v wire disconnected, there should be no voltage running to the 12v interior lighting and appliances. The only voltage the battery should see is when the trailer is being towed. The only draw the battery should see is when the electric jack is operated.

With this information, anyone experienced in 12v wiring with a volt meter and ammeter should be able to isolate the source of the discharge.

By the way, I have purchased new batteries with a bad cell.

[KYAvion]

Great write up, Silverloaf. So if I'm visualizing things correctly, the battery would receive a charge when the trailer is being towed even when kill switch is in the OFF position?

[silverloaf]

That is how I read my wiring diagrams. Everything to the inside of the trailer appears to stop at the kill switch. The electric jack, tow vehicle wire and feed to the kill switch are joined together, either at the battery or in the pocket I mentioned earlier.

The only thing I have not been able to determine is how the 110v-to-12v converter charges the battery. I suspect the converter voltage runs through the same primary wire ( kill switch included) as the one coming from the battery.

Interestingly, my manual says not to operate the trailer with the converter on and the kill switch off for fear of damaging the appliances. I think the battery is used as a buffer against current surge from the converter to the appliances. At least, that's my theory.

[KYAvion]

I think your theory is right about the batteries serving as a buffer to ensure a steady flow.

I bet you're right that the converter runs through that kill switch wire that you said is 8AWG. It'd have to be a relatively heavy gauge wire to run that distance and feed sufficient amps. In my trailer the converter is just before the rear bedroom. I'll have to take a look at the wiring this weekend and see what I can find.

[silverloaf]

When I was poking around the control panel above the fridge, I noticed someone had by-passed the ammeter. Not sure why. Maybe current draw from both directions killed it.

[tony.bare]

Thanks for all of the info. This interweb is is a very useful tool but is full of folks who , out of ignorance or malachite put out a bunch of false information. Not so with this forum. Seems like a group of friendly and informed folks. I have the owners manual with the wiring diagrams but I had no idea that there was a junction box under the front. That will be a handy test point. Now I have a good starting point . I just have to hitch up, crawl under it and start testing. Bluegrass season is starting up and it is time to get everything checked out and ready to have a trouble free season. Thanks for all of the usefull info.

[Razorback]

.......... Not so with this forum. Seems like a group of friendly and informed folks. ...... Thanks for all of the usefull info.

I agree..... something about Avion owners....