2024 Shasta Solar and Electric Issue

[jhall0125]

Hello, first-time posting, but I’m looking for some advice regarding an issue I’m experiencing.

Three months ago, I purchased a brand-new 29-foot Shasta travel trailer, which came equipped with a 200-watt solar system. When I first brought the unit home, I noticed that during the day, the interior lights and 12V-powered components (such as the awning, slide-out, and lights controlled by the information panel) would not work. However, the lights that bypassed the panel did function. Additionally, the AC thermostat stopped working.

Strangely, everything started working again at night. Fast forward—I sent the trailer back to the dealer, who worked on it for two weeks. Eventually, Shasta hauled it up north for further repairs. They reported finding a grounding short, which they fixed, and they also replaced the control box before returning the unit.

Today, I went into the camper to load it up, and the issue has returned. When I disconnect the solar panels from the solar control box, everything starts working again. According to the control box, the solar system is putting out 17 volts, whereas originally, it was reading 21 volts.

I know this is likely a solar or wiring issue, but has anyone else encountered something similar?

 

[Kevin D Pem]

To little information!

What is the voltage at the controller? What is the voltage at the batteries?
What is the controller (PWM/MPPT)?

Verify polarity on the controller wiring.

 

[jhall0125]

To little information!

What is the voltage at the controller? What is the voltage at the batteries?
What is the controller (PWM/MPPT)?

Verify polarity on the controller wiring.

 

[jhall0125]

To little information!

What is the voltage at the controller? What is the voltage at the batteries?
What is the controller (PWM/MPPT)?

Verify polarity on the controller wiring.

It is a 200 watt panel rich solar that is all the information I have on that, the controller says 17.1 volts, it is a 30 amp 12/24 volt solar charger controller model rs-pwn30p

 

[Kevin D Pem]

If you don't have a multimeters you need one.

The controller is a PWM controller (information obtained from Google search).

Because the controller is PWM there is no reason to monitor solar panel voltage. That would mean the battery voltage is 17 volts.

This means either you have an under voltage 24 volt system, or an overvoltage 12 volt system.

If 24 volt system, you have more than one dead cells in the bank.

If 12 volt system, your electronics shut down at 15 volts to protect itself.

No matter I assume you have a 12 volt system. That being the case the controller is designed to protect the batteries, and it has failed to do it's job. I would guess the final FET transistor has failed in the on state and is frying your batteries.

My suggestion is:

purchase an PowMr MPPT controller from Amazon and install it yourself! It is quite obvious to ME, that without any electrical experience, you are now armed with more information than the people you have been dealing with.

I suggest PowMr because they have a display in unit, and the price is right! I have used them for over 6 years and had no problems with them. I am not endorsing them. Victron makes better, as well as other makers. I have 1 Victron, but it has no display, and though I could put one on, I own a multimeter so won't.

So to summarize!

Without more data, I believe the solar controller is dead. A PWM controller in my view is nothing but a boat anchor usable in early days but a dinosaur of the past. Anyone that you should have let work on your rig would have known the problem within half an hour.

One last comment:

This is not rocket science!!!

This is the PowMr