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Thom12 · 01-19-2025, 06:45 AM

1998 PA Vision 36U
Does anyone know where the actual controller for the small solar panel is located? I see a fuse for it in the BCC but can't find the controller.

Thanks,
Thom

David 70 · 01-19-2025, 07:59 AM

I remember reading in a previous thread that there is no actual controller for those small solar panels. They do not create enough voltage to need one. I know when I measure mine it is just 17 volts.

SafariBen · 01-19-2025, 09:33 AM

How big is the panel? 12x36" aluminum framed? or 10x10" plastic? or something else. My 95 Safari came with a HUGE three 40w array for the house, and the smaller plastic for the chassis, that plastic one probably lasted six months and had no controller. The three 40w make perfect battery chargers for vehicles that sit all the time, PWM controllers for under $5.

Thom12 · 01-19-2025, 02:41 PM

It's the smaller plastic one. I bought a 7w replacement from Tractor Supply because the LED on bottom of A/C grill wasn't showing it was charging which I verified with a meter. Now I have 14.6v on both sides of LED but LED still doesn't show that it's drawing a charge.
So I am guessing it goes from the A/C grill down to the 3 amp fuse in BCC, which checks good but I still don't know if it's helping to maintain the chassis battery or not.

SafariBen · 01-19-2025, 06:35 PM

So you have 14.6 at the controller? That's likely not reaching the battery because a small charger will not be able to bring a good battery up that high, it will charge at 12.7-13.3 or so. You'll be able to tell it's charging only with an amp meter or by watching the voltage over days. What voltage is present at the fuse?

The LED won't light up with the same voltage on each side, it needs at least a little voltage drop to light up, and the current needs to flow to get that drop. The LED might be the only controller needed, Light Emitting DIODE is serving the purpose of the diode, all that's required for a small panel like that.

House Husband · 01-19-2025, 08:03 PM

LED is paralleled with 3 diodes in series to give the necessary voltage drop for the LED. That out put goes to the 3 amp fuse in the BCC.

Richard

Thom12 · 01-24-2025, 02:23 PM

Quote:

Originally Posted by House Husband

LED is paralleled with 3 diodes in series to give the necessary voltage drop for the LED. That out put goes to the 3 amp fuse in the BCC.

Richard

Thanks! That makes sense. But I will go back out and look tommow because I think my 3 diodes are in series through the LED. From memory, the positive output from panel goes to one side of led, othere side of led goes through the 3 diodes to BCC fuse. Negative side of panel goes straight through to ground.

House Husband · 01-25-2025, 03:02 PM

Quote:

Originally Posted by Thom12

Thanks! That makes sense. But I will go back out and look tommow because I think my 3 diodes are in series through the LED. From memory, the positive output from panel goes to one side of led, othere side of led goes through the 3 diodes to BCC fuse. Negative side of panel goes straight through to ground.

If you think about you theory, that would put all of the energy from the panel through the LED to the battery.

Richard

Thom12 · 01-25-2025, 11:39 PM

Quote:

Originally Posted by House Husband

If you think about you theory, that would put all of the energy from the panel through the LED to the battery.

Richard

Went out and verified it this afternoon. It is exactly as I described above, everything in series.
And when I pulled solar panel fuse in BCC, I measure the panel voltage (14.6 today) on the inboard terminal and chassis battery voltage (13.4) on outboard (left) fuse terminals in BCC. Put fuse in, both sides read 13.4.

SafariBen · 01-28-2025, 09:08 AM

The 14.6 is not getting to the 13.4v. Find out where and fix it.

Thom12 · 01-29-2025, 01:50 PM

Quote:

Originally Posted by SafariBen

The 14.6 is not getting to the 13.4v. Find out where and fix it.

Ya, I get that. That's the reason I started this thread to find out where and how.

SafariBen · 01-29-2025, 04:26 PM

OK, can't help you with that part. There is no controller, the diode, (LED) is the only "controller" on small panels, usually. A Powerprobe is nice to find stuff like this, it will show 14.6v on the end of that wire, or disconnect the batteries, then a test light will identify the only wire that's hot.

CaptronNZ · 02-06-2025, 03:33 PM

Quote:

Originally Posted by Thom12

1998 PA Vision 36U
Does anyone know where the actual controller for the small solar panel is located? I see a fuse for it in the BCC but can't find the controller.

Thanks,
Thom

Mine is a similar vintage and the controller is above and in front of the driver. Always use a controller to prevent over charging, and if it is an MPPT controller so much the better.