Need guidance swapping univolt out for Intellivolt 65amp

[phlegm]

My 1971 Airstream has a fully functional Univolt still humming in the corner and it it is working just fine. But I want to upgrade to a newer smarter unit.

My build thread
My 1971 31ft Sovereign -- Airforums

The original setup takes up a lot of space and it has everything compacted into one box, which is nice but its also a pain.

The entire mess sprawled across the floor.







This is the WFCO WF-9865 that I bought locally from an RV dealership.


I searched for a 1971 wiring diagram for a while and turned up a 1972 manual.

*if* I were to reuse (or continue using) the stock fuse box, where would the new power converter/charger connect into this.


I'm thinking about making a cradle that holds the new charger/converter and a pair of battery boxes. In those boxes a pair of Exide group 24 AGM deep cycle batteries (I already have them)

Ideally I'd mount a new fuse box to the shell of the AS permanently where the stock 12v wiring converges.

Then I'd use some sort of quick disconnect (like a winch) to hook up between the batteries and the fuse box.

I don't want to lose or compromise any of the stock functionality
ammeter shunt
12v power from the tow vehicle

This thread looks promising.
Photos Of Converting From Univolt To Intellipower/New Converter -- Airforums.com

[Lumatic]

This is what I did

[phlegm]

I saw that pic in the thread I linked to.
But my question is which connections on the original univolt do I hook up the new charger/converter to?

[TG Twinkie]

As I recall the Univolt connected to the back of the fuse panel.
The positive side of your new converter will connect to the buss which is connected to all of the fuses.
The negative side will connect to the terminal labelled negative load.
If you could post a pic of the back side of the fuse panel perhaps we could confirm the connection points.
It's been 8 years since I replaced the converter in my Argosy. My memory may not be exact. But a pic would help.

[Lumatic]

If you did not get instructions from the converter manufacturer for instructions can you contact them?

Typically, the chain is: shore power is hooked up to the converter, the converter charges the battery and the battery is connected to the fuse panel. Also the charge line from the tow vehicle is hooked up to the fuse panel. These connections are plainly labeled on the Univolt fuse panel. The converter may also need to be grounded to the trailer body.

[Lumatic]

Originally Posted by phlegm

I saw that pic in the thread I linked to.
But my question is which connections on the original univolt do I hook up the new charger/converter to?

Take this with a hefty dose of salt. in other words confirm confirm confirm. The converter does not attach to the fuse panel directly. The converter attaches to the batteries. The battery attaches to the fuse panel. I think this is how I did it, but it was awhile ago

Twinkle seems to describe a different chain. More than one way to skin the cat.

Randy at Best Converter is a good person to talk to.

[Lumatic]

Maybe this will help.

By the way, the glass fuses are getting hard to find, Especially the 40 amp. If I were to do it over again now, I would get a new panel.

BTW There is no 71 Service Manual. First manual was 72.

[phlegm]

Thanks for the picture Lumatic

Right now I don't have any batteries hooked up, I haven't left the yard with it.
I *assumed* that the power out of the univolt was split with a feed going to the batteries and a feed going to the fuse box.

I haven't taken it apart yet to get to the nitty gritty.

I bought it used so it did not come with instructions.
I could call WFCO or Randy, but I'd feel bad calling Randy since I have no plans to buy from him.

WFCO has the manuals online
Installation.
http://wfcoelectronics.com/wp-conten...ion-Manual.pdf

Operation
http://wfcoelectronics.com/wp-conten...ors-Manual.pdf

It looks like they suggest that the positive out does indeed "T" through the power distribution center to the battery(ies)


The only experience I have with onboard chargers and multiple batteries was on my pontoon.

That power path was easy as it didn't have any power from the tow vehicle.
shore power plug -> battery charger -> batteries
Then power from the batteries -> battery selector -> fuse box

I think the extra space between components made it easier to plan the path, you weren't trying to compact so many things into one small corner. That was part of the reason I wanted to attach the fuse box to the AS and then use the heavy duty quick connect for easy servicing. Another reason I wanted to make it into separate components is because I am still remodeling and if separate I only have to change the length of the wires in between.

I think I am overthinking it.
I need to do what I always do..
Pull it out, dissect it, make it better.

Thanks everybody.
-ron

[Lumatic]

Be careful messing with the innards of the Univolt. There are a couple of capacitors that can get your attention even unpowered.

I think Randy would be happy to speak to yu. Future customer you know.

[phlegm]

Last night I completely removed the original Univolt and its fuse box.

Take a pic of the existing wiring first in case anything goes awry.


My stock gauges don't work anyhow so no real reason to worry about them right now.

I built a wooden box to mount the charger/converter and mounted a 6 circuit ATC fuse block.

Hookup was simple.

Battery positive, AS blue wire, and a 2g wire from the charger were all connected at the new fuse block.

Battery negative, converter negative, and a negative wire from the AS were all connected together with a small bolt/nut/washers.



I still need to cleanup/organize the wiring a bit and add the second battery.

[phlegm]

I finished up last night.
The electrical outlet says it is a 20amp. It was the only one that had the pins in the correct orientation, sadly it was only available in what I consider an ugly color.




I just re-read the installation manual (OEM Installation Manual For use with WFCO ULTRA III Deckmount Converter WF-9800 Series) and it looks like the WFCO9865 has a max amp draw of 13.9amps, so there is a GOOD chance I was wrong about the plug being 30a.

I can turn on every single LED in my Airstream as well as the LED door light and 'standard' bulb in the 'scare light' and the charger makes no noise.

But the moment I turn on the light fixture that was in the original bathroom above the sink, even by itself, I can hear the charger fan kick on.

That fixture has (3) 1156 filament bulbs in it, the only interior light that I haven't swapped out yet with LED.

I still need to pick up a second battery box and cables to connect the 2.

FWIW, the place I bought the used one also had new ones for considerably more.