Community Forums

Jamezquita93 · 02-09-2025, 08:59 PM

So I have 2001 Thor majestic E450 … need help my solar panel monitor red does not turn on .. this solar panel connected to diode directly to batteries … is there a fuse ? somewhere it was working

Second issue my house batteries are not charging is there a solenoid that needs to be replaced and where is it located ?

FYI , Regular battery is working and new alternator

Please help

Argosy · 02-10-2025, 03:23 AM

Any answer you get without telling us where you have and lose voltage is a WAG. If you don't have a basic voltmeter you really need to get one and become familiar with it's operation. With a system that old it could be components, installation, corrosion, modifications by a prior owner.

SJ-Chris · 02-10-2025, 01:25 PM

I have some 2015 Majestics and I'm slightly familiar with the "solar panel" that is on the roof. I'm guessing it is a ~12" x 20" tiny panel, right? Those are typically ~10 watts of solar panel. Best case scenario when working they might provide ~3AH worth of charge to your batteries per day. Which means they are ALMOST worthless.

I installed a battery monitor on my Majestics. I haven't looked in a while, but I think the parasitic draw on the batteries when "Everything is off" (ie. in storage) is still ~0.6amps. 0.6 amps x 24hrs in a day = ~15AH per day worth of parasitic draw. So a 10w solar panel on the roof does basically nothing to help combat this.

The best thing you can do to prevent parasitic draw when you aren't using your RV is to install one of these on your batteries for ~$15:
https://www.amazon.com/gp/product/B07SBFKM5Y
Store your RV with fully charged batteries, then disconnect your house and chassis batteries with a switch like this and it can sit for months without an issue.

Or, if you are a DIYer, you can install inexpensive solar. Here is a link showing how I added 500w of solar for less than $400.
https://www.irv2.com/forums/f56/proj...er-529010.html
Could probably be done for less than half that if you only wanted 200w using 12v panels and a PWM solar charge controller.

Good luck!
Chris

twinboat · 02-10-2025, 03:11 PM

I had a 2000 E450 and there was a solenoid near the master cylinder that connected the chassis and house battery for charging while driving. The solenoid would close ( clunk ) when I turned the key on. It went bad so even though it clunked, the internal contacts didn't connect.
Yours could be in the same area or down by the house battery.

Jamezquita93 · 02-10-2025, 08:03 PM

Thank you

Jamezquita93 · 02-10-2025, 08:11 PM

Do you have a part number? Would your rv still turn on ? But not charge the house batteries? Does it have anything to do with convertor ?

Jamezquita93 · 02-10-2025, 08:13 PM

Thank you all of you

SJ-Chris · 02-10-2025, 08:36 PM

Regarding the alternator not charging the house batteries... Good news is that it is pretty easy to find the solenoid and it's pretty inexpensive and easy to replace it.

On all my Class C RVs, it has always been located on the firewall kind of near where the steering wheel is. All you need to do is trace your battery cables from the chassis battery and you'll find it connected to a solenoid. Most RVs are wired this way.

Probably looks something like this:
https://www.amazon.com/Starter-Solen.../dp/B0BGPR6KGP

Good luck!
Chris