1984 Airstream 345 owner (Newbie) need advice!

[Keyair]

Electrics is a blind spot for me, so I normally ask of peeps like Magnet18 for advice.
I tested it with my MM set on Ohms, and this is what I got each way...



Now, this dohicky fuse/diode thing is attached to the center pole of the start switch.... the only thing I can find in the service manual schematic is something the call “The Q1 Transistor”....
But then again I’m not sure yet that schematic applies to this unit.

[bobmiller1]

I agree.......fuse. Regards, Bob

[Air345Fly]

If I am reading your meter correctly you have .3 meg-ohms in one
direction and 3 meg-ohms in the other. If it is a diode it is
blown. If it is a fuse it is blown.

[Magnet18]

I'm thinking the schematic you sent me isn't the right one. Or symbol#10 is a serviceable connector, wondering if they changed the design and stuck a fuse there.

Not a transistor for sure. Still odd that a diode wouldn't have an identifying mark. A notched corner or something.

[Keyair]

I think I/we are chasing the wrong schematic.... cos its the only one out there!

Here is my logic.....

The "Kohler 3.5kw thru 7Kw Service manual" that I have via Brad, constantly shows a control panel with "Idiot lights" on the main electrical box, where the main "Start/Stop" switch is...
They always mention the PCB that is inside the box too.

My 7KW and this new to me 4.5Kw does not have Lights or a PCB...
Here is my 7Kw... Control box on RH side


And here is the 4.5KW control box, on left side...


And here is the inside of that 7Kw controller box


And here is the inside of the 4.5Kw


Identical from my perspective... Start/Stop Switch, 10a fuse, wires, and 3 relays... aside from the 4.5Kw relays having broken off their mounts

Now, I found, on Ebay this different "Service manual" and the title is specifically (With) "Relay controller"...


The Index makes it clear, that it is different..
Note "Section 5 specifically mentions "Re1 Diode"!



The manual is not with me yet(Monday I hope), so we will have to see if my hunch is correct.
Of course I will copy/share any new info!


My guess is that this version was cheaper/simpler and Airstream and others bought that version...

[Keyair]

I didnt see any markings on this thing but maybe there is a corner missing that I missed.
Let’s see if this manual clarifies the issue. I also have found the correct 4.5cm21rv SINGLE cylinder parts manual too. Only one Brad or anyone else had was the twin cylinder version.
I’m hoping this thing will run and work when I figure out the electrical start issue. What’s interesting is this unit appears to have had very little use. The carb butterfly and throttle shaft area is super clean.


So, I have a question about 50a conversions, which is next on my list, because it’s related tho the Genset issue.
Firstly, can anyone direct me to threads here that cover this... I’ve tried a search but it doesn’t work, and I know I’ve seen some.
It got me thinking.... my 345 can run both AC units from the OEM 7kw generator... which outputs 58amps.
I looked at the wiring diagram for the 345 and it looks like where the generator comes into the Motorhome, it splits the feeds into a 30a and a 20a circuit.
I had thought about putting a 50 plug on the generator and a receptacle on the Motorhome to be able to remove the generator quickly for service....
But couldn’t I just get a 50a cable and plug it into the generator receptacle giving me 50a without the hassle?
Thoughts?

[PeterH-350LE]

Originally Posted by Keyair

I didnt see any markings on this thing but maybe there is a corner missing that I missed.
Let’s see if this manual clarifies the issue. I also have found the correct 4.5cm21rv SINGLE cylinder parts manual too. Only one Brad or anyone else had was the twin cylinder version.
I’m hoping this thing will run and work when I figure out the electrical start issue. What’s interesting is this unit appears to have had very little use. The carb butterfly and throttle shaft area is super clean.
Attachment 386555

So, I have a question about 50a conversions, which is next on my list, because it’s related tho the Genset issue.
Firstly, can anyone direct me to threads here that cover this... I’ve tried a search but it doesn’t work, and I know I’ve seen some.
It got me thinking.... my 345 can run both AC units from the OEM 7kw generator... which outputs 58amps.
I looked at the wiring diagram for the 345 and it looks like where the generator comes into the Motorhome, it splits the feeds into a 30a and a 20a circuit.
I had thought about putting a 50 plug on the generator and a receptacle on the Motorhome to be able to remove the generator quickly for service....
But couldn’t I just get a 50a cable and plug it into the generator receptacle giving me 50a without the hassle?
Thoughts?

several ways to skin an Airstream. The easiest is to add a plug on the 20 amp circuit (rear AC) of the generator and run a 20 amp cord to a 50amp splitter on the post. That way you keep your original 30 amp service. Even though the transfer switch for the 20 amp circuit will regulate the power flow, I would disable whats referred to as double throw switch C that switches between front and rearAC and hard wire it to the front AC or only have option micro wave/front AC working.
If you want to lug a heavy and stiff 50 amp cord around, I am sure BobM or Chris would be happy to chime in.

[Keyair]

Thanks for the input Peter as always!
Will research my options.
As always, my craziness grew out of a simple thought.... how can I make the Genset easier to quick-disconnect!

Had a busy day today!
Found some used solar panels for sale... sifted thru a stack of them(200+), and cherry picked the best of the lot. Ended up with 8 that were between 21v and 23v, which was more than I planned to buy.
But they were $25 each, so I’m not feeling too bad.
These are Uni-Solar 64w/4.8a rated panels.... and whilst they are in solid frames, they are actually flexible panels. Just have to take the frame off.
2 fit well on the roof in my curved frames, and I have a plan for 2 or 4 more, in a portable array.

I tested them in series and was getting 160v plus in this pic.


One will go at the front of the MH here to replace the Unisolar 32w shown. The 32 will move to the mid section of the roof or rear where I fits perfectly next to a 64w.


Here.
The 64w is basically 2x 32w units laminated together.

[Keyair]

When I got home the 4.5cm21rv parts book was in the mailbox.
It’s not the final word, but it’s confirmation of a few things...


No oil pump in this model... which explained why there is no oil filter.. just splash lubricated.


And there, on the last page, they show 2 separate types of controller... and in the left one they label a circuit board, and in the right one they label a relay bracket.
And there it is, part N is referred to as Diode RE1.

[Air345Fly]

If that is a diode then it is an unusual package.
On testing a diode with a multimeter you must put the meter
in diode mode to get a good reading. I looked up your
meter and to put it in diode mode you press the "select"
button when the meter is in the ohms setting.

You should get a large difference in readings between
reading one direction vs the other direction. Perhaps
you could post some close up pictures of both sides
of the diode? Could you post the electrical schematic
of the generator from the manual?

[Keyair]

Will do!

[Magnet18]

Yep, part number came up with this, replacement still available if yours tests bad. Probably not the most likely part to fail though.

https://www.partsfortechs.com/asapca...roducts_id=509

Couldn't find a datasheet though, likely a koehler custom part.

[Keyair]

Thanks.
Will order a new one regardless.
Service manual will be here tomorrow, so will hopefully have a definitive answer and will post the schematic.
I took some measurements yesterday and confirm that theoretically, this 4.5kw will go into my generator compartment sideways.

[Keyair]

Scan of the 4.5CM21-RV parts listing attached!

[marcvl]

Peter: interesting thought to keep 2 separate 30A and 20A circuits with a splitter. That definitely is simpler to implement and allows us to keep the existing 30A power cord.

Steve: I’m assuming you’ll also install an inverter in combination with your solar implementation, so you can power your 110V outlets without shorepower/generator. If that’s the case, maybe that inverter is connected to the 30A circuit? Only downside is that it wouldn’t be able to power the back AC. That’s probably ok because you would never have enough solar power+battery capacity to power 2 ACs for any significant length of time.

[Keyair]

Yup.
My current plan is LifeP04 lithium batteries in a 24v or 36v config, with a 4000w inverter.
I believe I can get at least 1000w on the roof on the Motorhome.

Today I just couldn’t help myself, so had a quick play with one of the unisolar panels.
Gave it a good scrub to get ingrained dirt off, and did some tests.


On a lightly overcast day, this panel was putting out a solid 20.5 to 21.5 volts.
I’ve read that even tho these panels are “Old Technology”, they perform better in less than direct sun than the newer panels....
Test time...
Used Unisolar panel rated @64w/4.8 amps on left .
New Renogy panel rated @100w/5.7amps on left..


Measured output laying flat on the grass at 2pm with diffused sunlight.
Unisolar.


Renogy.


Interesting eh?
Oh, and I managed to pry of one of the unisolar frame ends.
Found the production date...
Yup, 13 years old. [emoji3]

[marcvl]

wow, 1000W using 64W panels, that's 16 panels!! quite a bit for 1 roof :-)

[Magnet18]

Note for your test open circuit voltage is only half the story. Hook them both up to identical loads then measure the voltage across that load, the higher the voltage the more power being output.

Without a load the voltage doesn't mean much because current is zero and therefore power output is zero

[Keyair]

I don’t think I could get 1000w of 64w panels on the roof...
But my previous test a few pages back I managed to theoretically place 9x 100w Renogy compact panels on my roof, iirc.
From there it’s easy to piece together another 100w or more in 50w panels.
The 64w panels might well become static panels for placement when parked if needed.
They are lighter and, if folded face to face, more compact than the the Renogy panels. Store em in the shower or under the rear floor maybe.
I sketched out an idea for a pole mounted array, to come off the tow hitch a while back. Also arrays that just clip in over a window like a shade...
I know I am crazy, but I’ve got a simple design for those on paper too!

Still not enough wattage to run both ACs tho... need to get more panels....

Thanks for the input Magnet,
Maybe a shootout test with 3x 64w panels vs 2x 100w panels is in my future. [emoji3]

[Keyair]

Manual for the 4.5-7.5 gensets arrived.
I copied and scanned it, which took me a while to get good copies... 62 pages.
It confirms what I thought, that there is another version of the Kohler generators that has a completely different, simpler relay based controller.... and I have 2 such units, so it’s a win!
Will post the copy in a few.
The Starter switch, carb rebuild kit, brush set, arrived from Partsfortechs, pretty quick!
Also, a set of 4 relays arrived too.


I ordered some more stuff, including this diode. I have confirmed by close examination that the current diode has no markings or any indication which way it goes in the holders, but using my MM set as suggested I believe I have confirmed it’s good.
One way reads this:


And the other way reads this: