Solar issues while on the road!!! Truck alternator too??

SA

Sagefemme

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Western Oregon
I am in Arizona on the road, currently in Sedona but been a few other places in the south. Seeing amazing birds and taking amazing hikes. HOWEVER we are having electrical issues. It started with the solar panels delivering a small amount of power first thing in the morning but every day quitting after a short period of time. It also charges briefly in the evening. This has been consistent for a week. At first I think the truck alternator was charging the batteries and we were doing enough driving to get by. Now it seems the truck is not charging the batteries either.

We went to a random RV dealer that had a service department. It was 4:45 in the afternoon and they looked at me like I was crazy walking in without an appointment (they were booked out for weeks) but I guess I looked sad enough that they took pity on me and took a look.

Their conclusion was that the solar charge controller was bad, and they did not know where in Tucson one could get a Zamp solar charge controller. Order one on Amazon, they said. Not so helpful given we weren't planning to stay in town. But they were very nice and didn't charge us anything (shout out to. ).

Then we decided to get someone to look more comprehensively, and met a mobile RV service guy in the parking lot of a Red Robin. He, strangely, didn't have much of anything for tools with him but did a bunch of stuff with a multimeter (kinda the same routine as the first guy) and came to the same conclusion. While I was waiting for him I spoke to Zamp on the phone and they said they could ship a new controller to me overnight, but to please have the service guy check the power coming out of the panel, and a few other specific things. He couldn't check the panel right at the panel because the wiring was not accessible but he did check the ancillary solar port on the back of the camper (flatbed Hawk). He got 19.25 volts. The other places he checked he also thought were fine. I didn't have a ton of confidence in him but now it seemed worthwhile to order a new solar charge controller, which I did, and which we installed, and got exactly the same results: small amount of power comes in first thing in the morning and last at night, but it amounts to almost nothing. The rest of the day we get 0.0 volts and lots of times a red light is flashing which I guess means "weak solar" and "not charging." Again, we have been doing plenty of driving and when we park our batteries are at 12.0 or even 11.9 which I don't want! We have turned off the fridge a few times to conserve since that's just about all we use, anyway.

We are at a campsite with electric right now, so the controller is acting fine and says the batteries are at 13.6.

Everything was working fine for the first 4 or 5 days of this trip. I am not well versed enough to do much in the way of diagnosing or fixing, but I could go buy a multimeter if anyone had a brilliant idea. I really wanted to be mostly boon docking and getting away from people on this trip, so it's disappointing. We are still having fun but I'm tired of worrying about this and with spending time in cities looking for solutions or waiting for packages to be delivered (that's another whole saga).

Does anyone have a recommendation for someone good in Phoenix or Las Vegas or thereabouts who might be able to help us? I get the impression RV fixers don't always know electricity stuff very well.

Thanks all who may reply!
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The display shows your battery at 50% state of charge. What is the battery capacity? Is the truck not charging the battery? The 12.0V when parked is with loads on the battery or with everything disconnected?

Based on your photos the manual for the SCC1011 shows:
1745775126216.png


Clearly the issue is not with the controller. The 19.25V at the exterior solar port suggests the panels are working fine. I suspect the exterior port is wired in parallel with the panels. Maybe there is a wiring issue somewhere between that parallel connection and the SCC1011. Did the service techs check the voltage where the solar connects to the SCC1011?

1745777594162.png


The SCC1011 has an optional external temperature sensor, but that would show an error code and flashing LEDs if it was sensing an over temperature.

That it its working in the morning and evening is curious. Maybe something temperature related?
 
The batteries are deep cycle AGMs of 100 somethings (amp hours? Amps? each. The 12 volts is with everything off. Yes, the refusal to charge during most of the day in Arizona suggests something temperature related.
 
Yes the tech checked where the solar is connected to the controller and said it was fine. BTW the SC1011 is the new controller that Zamp shipped to me two days ago. The old one was ZS 30A I believe. But the new one is behaving exactly like the old one.
 
If you don't already have a copy, here is your manual for that device - https://cdn.shopify.com/s/files/1/0344/2973/0953/files/SCC1011_User_Manual.pdf?v=1683736525

If you are getting 19.5V at the controller input (I would get a simple multimeter to use and keep in the camper) and nothing on the output of the controller then the controller is either busted (two in a row???) or misconfigured. (But how could the config change mid trip?).

Another anomaly, your alternator charging from the truck is either directly connected or going through an isolator or DCDC charger. Which is it? If alternator, then start the truck and measure the voltage at the TRUCK battery. Since you are not having truck issues, I assume you will get 14+ or so on startup? A smart alternator will fiddle with the voltage to meet the demands of the truck, so if you have one those, you should see at least 13+ volts. Got that? Good. Now measure what you are seeing on isolator or DCDC input. Should be the same or similar (some voltage drop is expected. What is that number?

Another crazy thought, check the connections on the "bus bars" both +ve and -ve. For TWO charging sources to quit at once, some common denominator is highly likely. And while you are at it, any other connectors (truck to camper) should be checked too.

Now, back to your controller.... If you disconnect the controller (just unscrew and remove the ground wires on input and output) and measure the voltage on the solar panel wires in full sunshine, you should see that 19.5V or more (which solar panels do you have? We could confirm their power characteristics if we knew that). And you should see 11V or more on the battery side of those disconnected wires. Make sure you get the same 11v or more by measuring directly on the battery posts as well. This will confirm that everything else is ok.

If you conclude that the controller is indeed busted, consider getting a MPPT vs the PWM controller you have. They are more efficient. Victron comes to mind as a reliable brand.
 
Thank you, Vic! At the moment we are camped on a plateau with a beautiful view and no multimeter so no investigation will occur this evening. I don’t understand why I didn’t put the multimeter we have at home in the camper for this trip. Probably because in the 10 months we’ve had the camper we have taken many shorter trips (long weekends) and had absolutely no issues, which I guess lulled me into a false sense of security.

One thing—the solar charge controller in the picture is the NEW one Zamp just shipped to me. I now believe there was nothing wrong with the old one, either.
 
Truck is old (2004 Ram) can’t imagine there’s anything smart about the alternator! I believe it’s connected directly. Solar panel is 160 watts and I believe was installed by Four Wheel in 2016 when they built the camper.
 
If not fixed by the time you get to Reno, give Zero Declination a call (or better yet, call before you get there). KP and crew are awesome solar folks for campers.
 
Can't help from wondering if there are fuses or hidden ones either the positive or negative wires coming off of the batteries that are blown.
 
I have not explored the battery compartment but will do so today or tomorrow. The vehicle was not connected to the camper batteries until recently (I went to All Terrain Campers in Dec 2024 to get a frame issue repaired and while I was there Marty and crew did that work as well as fixing the frame damage).

This morning’s update: The solar panel started to generate power at sunrise, as it has every morning. We got to 1.7 amps coming in before it quit. Total of 0.9 amp hours. I expect this evening, when the sun is again coming in at a low angle, we will generate power again until sunset. Yesterday morning we were parked in shade under a tree AND it was a cloudy morning, and we got 1.6 amp hours before it stopped. Ironic that we get more solar power in shade than in sun!
 
Is it possible that angle of the sun affects our problem? Hard to imagine, but it seems to be the variable of interest, n more than temperature. It was 39 degrees when we woke up this morning at elevation near Sedona.
 
Electrical is always a hard one to fix as there are. Any possibilities where the failure is. Wires need to be traced from beginning to end for broken, shorts and wires pulling out of connectors. Usually means hands on tugging and pulling and also using a volt meter.

Almost sounds like a loose wire, bad ground, broken wire. It starts getting amps then kicks out. Losses continuity.

Might also check the roof plug for clean and tight connection.
Everything is suspect
 
Long distance diagnosis with the on site person having no test gear is challenging at best, and can just be guesswork.

Something seems to be limiting the panel output current. That is the hint the blinking red light seems to be giving. It could be wiring as pvstoy mentioned, but the repeatable behavior of reaching a current level in low sun then cutting out, and charging longer in indirect light conditions, makes me suspect the panel has a failure, and the intermittent behavior is panel heat related. To determine this you would need to access the connections and try directly applying load to the panel in sunlight through an ammeter. That is going to be impractical with your limited equipment, but an electrical shop such as Taku recommended would be able to do that.
 
pvstoy said:
is the solar and alternator inputs separate and each home run to the camper battery?
Click to expand...
This is a good question. Because two of your three sources for charging died at the same time, I am not considering a failure of the PV panels, solar controller or alternator.... it has to be a common wire/connector/system that has failed somehow. Separate runs have to join somewhere. Do they?
 
The OP never mentioned a battery monitor - only voltage levels. I’m not sure we really have an indication the truck charging isn’t working - we just know it’s just not fully charging the batteries with the amount of driving they are doing. It may be that, even with quite a bit of driving, the old standard 10 awg wire through an isolator isn’t allowing enough current to catch up those large AGMs that have been deeply discharged due to multiple camping days of falling behind due to lack of solar charging.

It makes sense to carefully check wiring for good connections as step one, but I’m still suspicious of the panel.
 
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