trailer not charging

Mine uses a 40 fuse.

If you are truly talking a '91 (24 years old), the charger has likely thrown in the towel. It's probably time for a multi-stage charger even if the old one still lives (you'll save your battery in the long run).

ya im just going to grab a multi pack of standards and a multi back of minis

Jebby14 wrote:
yes the panel is under the fridge. sadly im at work so im working off memory. this will help. was just hoping to grab some new fuses on my way home.

Get some 20's 30's and 40's, even 10's. You'll probably use them up or need one in the future.

yes the panel is under the fridge. sadly im at work so im working off memory. this will help. was just hoping to grab some new fuses on my way home.

Post your model number for the converter/charger setup. should find two large amperage ATC fuses off the self on the fuse panel. These two fuses are in-line between the converter/charger unit and the battery terminals. There should also be a in-line fuse very close to the battery terminals for you to check.

On my WF8900 series distribution panel this is where the two REVERSE POLARITY fuses are located. The two green ones off to themself.


I think your DC fuse panel should be under your fridge in your prowler.

Roy Ken

I should ad. anyone have any idea what size the fuse would be?

thanks guys, I checked the battery via my multimeter and was getting 12.5v post to post. plugged in I get the same 12.5v I know its not charging. we are taking it tonight. I will poke around and see if I cant find the reverse polarity fuse. that would be my guess. after that I guess ill just go down the line until I find it. as always very helpful.

It is a common error to connect a battery backward and blow the reverse polarity fuse. Check the polarity.

When on SHORE POWER the 120VAC feeds the CONVERTER/CHARGER unit which produces your charging DC VOLTAGE. Both the Converter/charge and your trailer feed the same point on the 12VDC DISTRIBUTION PANEL where all of your 12V FUSES are located.

You should be able to read your BATTERY DC VOLTAGE here with the SHORE POWER turned off. 12.6-7 VDC would be for a fully charged trailer battery.

When you turn ON the shore power this DC VOLTAGE should JUMP up to 13.6VDC or higher depending what the charge status is of your converter/charger is doing. If you see the 12.6-7VDC JUMP up to the 13.6VDC then you know your battery is being charged.

If you don't see your 12.6-7VDC at this point then something is not connected. You may have a DISCONNECT SWITCH opened, bad terminal connections, or an IN-LINE FUSE blown. It could also be the converter/charger is not working producing the 13.6VDC. It could also be the two fuses labeled REVERSE POLARITY on the fuse panel are blown because you connected the battery terminals in reverse order or sparked to ground for a second.

Start at the 12V Distribution Panel and work you way back to the battery to see where you lose the 13.6VDC when shore power is turned on.

Another BIG CLUE is when you turn on your ceiling lights in the trailer which are connected to the Distribution Panel. They should come ON without shore power turned ON. This would also tell you your trailer battery is connected properly to the 12V Distribution Panel.

Think I sent you a typical 30AMP Power diagram awhile back showing how all of this is laid out.

An inexpensive MULTIMETER from LOWES/WALMART/AMAZON ($7-$25) is a must have item around the trailer systems. Harbor Freight (I think it is) will give you one for free when we purchase things from them.

Most Often when someone says they just installed a new battery and it doesn't charge you eventually find out they installed the terminal wrong. Find the word NEG or the '-' symbol stamped on the battery case and make sure this is the terminal that goes to FRAME GROUND...

Don't worry about bugging us - we will all be asking you questions before too much longer...

I will admit you are playing around with alot of things recently but that is how you learn the business...

Roy Ken