Comfy with 12V, but 120V is throwing me...

[SafariFaye]

Faye is new to us, as is owning an RV. I'm coming from a 12 V automotive background (and I teach physics) so the electrical system isn't SUPER scary, but the combo of 12V and 120V shore power is keeping me awake at night.

We have a 1964 Safari that still has the original converter that changes the 120V to 12 volt and 19 volt AC (according to other posts and the wiring diagram from the owners manual).

I purchased a new converter/battery charger and I understand that I plug that into the 3 prong 120V plate at the rear of the utility access (where the Harbor Freight battery charger is plugged in...classy!).

What I'm not sure about is how I switch from 120V "Street Power" to 12V only. The original set-up has a "fans-pump" switch and a "city-battery" switch. Do I just disconnect them?

Is the switching responsibility handled by the new converter/charger? Does it automatically switch when shore power is disconnected? Does the battery just "kick in" when 120V power is not available? Like I said, understand the theory, just want to be smart with the execution.

Have any of you done a similar conversion/replacement? If so, I'm all ears. Plus, I'm also looking for deep cycle battery recommendations. No A/C, no TV, just lights/water pump/fridge/water heater. She's basic, and that is how we like it.

The converter/charger is an IntelliPower 9245. I have a new fuse panel and 50A circuit breaker. The original works, but looks like some soviet-era reject. It really looks scary.

Any help y'all can provide may save me some (additional) grief. So far the forum has been a real asset. Thanks in advance.

J.B.

[mimiandrews]

Think in terms of two separate electrical power systems in the trailer. The basic system is 12v DC, and it runs the stuff you've just got to have--lights, water pump, fridge control boards, furnace fan, etc. It runs off the battery when boondocking.

The second system is 120v AC, just like you have in your house. This one works only when plugged into shore power--30 amps capacity required to run everything. This system also powers a converter (transformer/rectifier) to supply power to the 12v system when on shore power. Conveniently, this unit recharges the battery when on shore power.

For use when traveling, there's also a third system. It operates the tail lights, turn signals, and marker lights, and is powered from the tow vehicle through the umbilical cord. It also powers the trailer brakes through the brake controller in the TV.

[DKB_SATX]

You definitely want to swap the Intellipower in for the old one. You'll get back 30 lb of cargo capacity and it'll be MUCH nicer to your battery.

I'm not sure if your Safari is any different than our '70s setup, but for the Argosy all of the lighting inside and out is 12v. Really all the 120v system does besides power the converter to provide 12v is provide power for the AC, allows us to run the fridge without using propane and powers the various outlets so we can plug in our modern electronic toys.

The presence of the "City/Battery" switch hints at something more complex in your trailer... perhaps there are light fixtures with both 12v and 120v bulbs? Or perhaps it's just an older version of the "Store/Use" battery isolator switch in modern Airstreams that lets you take the battery out of the circuit once it's charged so your "soviet-era reject" Univolt won't boil off all the electrolyte.

[TG Twinkie]

I installed a 9245 in my trailer. Here is a drawing.

http://i1166.photobucket.com/albums/...ilerWiring.jpg

[overlander64]

Our 1964 coaches were the first to be equipped with a standard Univolt, and there were a few characteristics that can make the task of switching to a new power converter a little worrisome. All of the ceiling lights as well as reading lights are twelve volt and operate via battery/Univolt power. The area where the differences arose was in how Airstream handled power to the ceiling fans (if so equipped), furnace blower motor, and water pump . . . rather than depending upon the Univolt for power, these had individual transformers mounted on their electrical supplies. These items had already been removed or were defective when I purchased my '64 Overlander so I didn't have to deal with these as issues. I am not certain whether anything particular needs to be done when trying to use thes OEM devices with a new power converter in the system.

Good luck with your investigation!

Kevin

[SafariFaye]

Here are some things I found out... and picture to go with it.

If ANYONE has ideas on what these are/how they need to be hooked up...beer is on me.

I'm stumped. Not the 120V any more, but actual "Soviet Reject" box that I pulled out of it.

I wish I could find some sort of wiring diagram like a car has, more detail, wire colors, etc.

I'm committed now. Or I'll be committed later. I just turned our Airstream into a giant rolling tent. Oh, my!

[SafariFaye]

I can supply more pics, if it might help.

J.B.

[SafariFaye]

Here is the city/battery switch (and the fan/light switch, with the wrong plate). You can tell the difference by the hand-written identification.

I'm convinced now that these are unnecessary. I'm also pretty sure that the converter had 1 input from the 120V and 2 outlets (1 that was 12V and one that was 19V). Problem is, the 3 input/output wires are the same color (brownish with blue stripe).

The fuses are the black things with the white wires. I think I need to connect whatever went to those to the new fuse box... and I know I need to find the "hot" wires in from the 120V (and turn it into 120V plug).

Like I said... Any ideas?

[TG Twinkie]

The items in the first 4 pics are automatic reset circuit breakers. I can't tell by the photos but I would bet that one wire from each of them are all connected together and connected to the DC output of the Univolt.
Did you place the green tags on each?
If I am correct, and I think I am. Each of the circuit breakers supplies the power to individual circuits in your trailer.
I think you said there is a Harbor Freight battery charger that was used by the PO. It may have been in one of the contributors post in this thread.
At any rate. If you have a battery charger, you can ID each of the circuits and their use. If the green tags give you that information you are one step ahead.
I posted a drawing of how to wire the trailer above. Can you interpret the drawing?
If so, we can take it one step at a time and get your 12 volt system functioning again.
I would like to see the condition of the wires from the battery as well as any heavy duty (large wires) associated with the Univolt and any fuses, specifically 30 to 50 amp that may be wired into the system. I could be all circuit breakers. Provide a list of all of the circuit breakers with the capacity (ampere rating). Each should have that info on the back.
Then it will be decision time.
You have already purchased the 9245, so tha decision has been made.
Next:
Do you want to upgrade to more modern protection equipment? Do you want to replace the circuit breakers with a newer version or change over to using fuses?
I am reasonably certain that the larger gage wire will need to be upgraded. Yes or No? Pics will help.
The smaller wiring running throughout the trailer may be functional. You need to check for obvious damage or signs of burning etc on the parts of the wiring you can see.
If you can get back with the info and any questions. We can get started.
I and others here will be glad to help.
You won't be in a rolling tent for long. Depending on the time you have available.
When we get the 12 volt lighting and battery charging systems functioning. Then we can look at the pump, furnace and fan situation.

[Dan@LED4RV]

Originally Posted by SafariFaye

I wish I could find some sort of wiring diagram like a car has, more detail, wire colors, etc.

If you could find the manual you would most likely have more questions than you do now. Most of the old manuals were written for more than one model and after you read it you will ask, "Do I have one of those, If I don't, did someone take it out?
Your at the best place, Airforums and can post pictures.

[TG Twinkie]

Meant to ask for pics of the AC power panel and the shore power cord setup.
We can start by using an extension cord to power the battery charger to check things out. Then wire in the converter and protection devices. The converter can then be powered by an extension cord.
Just be careful and don't jam the cord in the door and pinch it. Sparks could fly.
I would not plug the trailer in using the shore power cord until things on the 120 volt side are completely checked out and deemed to be safe.
If you are not comfortable working with the 120 volt AC side. Then I would recommend contacting someone with experience
When you are done, you can write your own manual with drawings to match.

SAFETY FIRST!!!!!

[SafariFaye]

The green tags are marking each of the connections as they were set up before dismantling the system. Learned that from years of disconnecting wires in classic cars. Easier to retrace your steps.

Found the 120V supply to the univolt. Setting up a "wall socket" 120V for the new converter to plug into.

Working backward from the fuses, I have identified the 4 "systems" that were in the AS. Patching each one of those into a new fuse panel I ordered from Vintage. Following the diagram supplied by you kids and vintage. The water pump, ceiling fan and furnace have all been replaced with new(er) items. I will test them is 12V before finalizing the install.

I will post pics and results as the day progresses. Might need some hand-holding. The tear-down answered A TON of questions.

Thanks...stay tuned.

J.B.

[SafariFaye]

alright... it has been quite a journey. After removing all of the electrical parts from the utility area, I found a leaky pipe and took the time to install new. No reason to get all of the new electrical all wet, and mess up the floor of the utility area. That is what took so long.

Got everything hooked up yesterday and everything works EXCEPT the 12V lead to the lights in the trailer. It is a black/white "romex" type connection that sparks and blows a fuse EVERY TIME I try and connect the black to the 12V hot and the white to the ground bar on the fuse panel.

Like I said, everything else is fine. Water pump...check. Ceiling fan...check. 120V plugs...check. Scare light (which didn't work before)...check. 12V lights...BLAM...blown fuse.

Anyone got any ideas? This one is got me baffled. Thanks for the help so far.

J.B.

[overlander64]

Greetings SafariFaye!

Originally Posted by SafariFaye

alright... it has been quite a journey. After removing all of the electrical parts from the utility area, I found a leaky pipe and took the time to install new. No reason to get all of the new electrical all wet, and mess up the floor of the utility area. That is what took so long.

Got everything hooked up yesterday and everything works EXCEPT the 12V lead to the lights in the trailer. It is a black/white "romex" type connection that sparks and blows a fuse EVERY TIME I try and connect the black to the 12V hot and the white to the ground bar on the fuse panel.

Like I said, everything else is fine. Water pump...check. Ceiling fan...check. 120V plugs...check. Scare light (which didn't work before)...check. 12V lights...BLAM...blown fuse.

Anyone got any ideas? This one is got me baffled. Thanks for the help so far.

J.B.

I would suspect one of two things in regard to the ceiling light fixtures. The first problem that I had with my '64 Overlander was with shorted switches on the fixtures. At the time, I was able to find "generic" switches at a local auto parts store (AC Delco) that solved much of the problem. In the process of replacing some of the switches, I ran across some poorly made connections that were likely repairs made by a prior owner . . . once those were cleaned up, I haven't had any additional trouble.

Good luck with your investigation!

Kevin

[TG Twinkie]

If the Romex type wire is solid conductors I would not expect it to carry DC voltage. Normally the DC circuits are wired with stranded wire. Single conductor. Unless this light fixture has a step down transformer. Which I don't think it does.

[thecatsandi]

those look like self resetting breakers.

[SafariFaye]

I think I may have found the problem.

We mounted the new fuse panel to the metal battery box. The DC connector shorts out when the metal battery box is installed in the trailer. The DC connection works just fine when the box is out of the trailer.

It seems that I am breaking some sort of grounding rule and shorting out the DC connector when the metal battery box is making connection with the frame (or maybe touching some plumbing...but I don't think so). That is the only difference when the rig is in/out of the utility area.

So, we are either going to insulate the fuse panel from the metal battery box or built a new box that won't ground out.

Man, this has been an education/adventure!

J.B.

p.s. I'll post pix when I calm down.

[SafariFaye]

I would generally agree, but the connection for my ceiling fan/exhaust fan/scare light are all solid conductors. Appears to be that way from the factory. The AC lines are also solid core "romex" style too.

Just gotta go with it. Not going to gut her to switch it out. They work fine when the system is hooked up.

[SafariFaye]

SUCCESS!!!

Was a loose wire-nut that was shorting out a lighting fixture on the aluminum skin above the kitchen area. The aluminum was acting as a conductor, and shorting out the entire 12V lighting system. Just took some trouble-shooting and a bit of hard work (and luck) to find the culprit.

Thanks so much for the help.

[TG Twinkie]

We knew you could do it. Enjoy being in the light.