Fuse Panel

[Dd48]

So I have a question period we recently purchased a 2010 Keystone Outback 21-ft super light. When we got it home and plugged it in to our house, we were cleaning it, had the radio on and some of the lights were on because they had already been on prior to the purchase. All of a sudden we realized that the power was out, the radio was off. Long story short my husband went through the panel box and to the left of all of the individual blue(15amp?) fuses are two main fuses that are separate. The fuses that were in there were 20 amp, and as I say there were two of them. They were burnt, we have since went online to try and figure out to ensure that the 2 fuses were the right amperage. But it seems every diagram we've looked at it is actually showing 40 amp fuses in those two slots. so I guess my question is if anybody knows is it supposed to be 40 amp fuses, or should it be the 20 amp fuses that we initially discovered in there blown. We're going camping next week and we obviously don't want to run into this issue again, so any advice/insight/information will be welcome and appreciative . Tia.

[chuckster57]

Welcome to the forum
Those are called “reverse polarity” fuses, designed to blow if the power is connected wrong at the battery.

Since yours seemed to be ok for a bit, I would start at the battery. If you have any doubts about its age, or previous care replace it. Get a Deep Cycle battery. Once you have that figured out get 2 20A fuses and try again. Using a volt meter test at the battery while plugged into shore power, you should see 13VDC.

Post back with your results and we will try to get you out camping on time.

[flybouy]

I would see if you can find the model number on the converter to verify the fuse size. From your description it sounds like they are the reverse polarity fuses that provide protection to the converter in the event of the battery being connected incorrectly. 20 Amp sounds too light to me.

You bought a 10 yr old camper so I would get that battery checked out by taking it to a battery retailer that can load test the battery. Many auto parts stores that sell batteries offer this service free of charge.

You say "all the lights were still on" would have me guessing that the battery of unknown age and condition was drained and "all the lights" (most likely incandescent) finished it off. The PO (previous owner) may have blown the fuses connecting the battery and just used what they had to get it sold.

While you're having that battery tested do yourself a HUGE FAVOR and check the tires for manufactured dates, air pressure, and who made them. Trailer tires usually rot before they wear out. Depending on tire manufacturer they should be replaced by year five, some before that. A 10 yr old unit should be at least on it's second set of tires with a third set due or over due.

[ChuckS]

https://wfcoelectronics.com/wp-conte...Manual-web.pdf

page 4 will tell you exactly what size reverse polarity fuses are required for your converter... if this is the 55 amp board then 40 amp fuses are what is called for... your converter is an 8900 series and most likely the 8955 but you can look at the converter located down in the power panel and get the model number to be certain

[Steve Schmidt]

I have an associated question...


I recently purchased a 2008 23rks, and managed to hook the freaking battery up backwards. I realized what I had done when I went to bring in the slide and the controller worked backwards! In other words, still power going through the system. I immediately swapped the leads over, and the slide works correctly now. Still lots of juice coming from the battery. But I have no lights, electrics, in the trailer when on dc. When I plug the trailer in everything works fine.


Checked the 40amp reverse polarity fuses, they seem fine.


Are there breakers or fuses somewhere other than in the panel?

[Bostongone]

Steve, those 40 amp reverse polarity fuses should be toast! Check them with an ohmmeter to be certain and for chuckles just replace them. Like I said if the battery was reversed they don’t survive!

[Steve Schmidt]

Thanks, I took your advice and decided to pull the 40-amp fuses and replace them. So I pulled them and then thought "well maybe one of these works, which is why the slide is still working" so I went back and put them both back in to see if anything worked. And now everything works.


So the battery was definitely hooked up backwards, the controller definitely got taken off-line, but the fuses are still intact and now it's all 100%. Hmmmn.

[Bostongone]

So took old fuses out, did you put new fuses in and things started working? Then swapped old fuses back and things are still working? Not logical? Hope all is well though! I would keep an eye on the battery voltage in case the converter was damaged though.

[Dd48]

Originally Posted by chuckster57

Welcome to the forum
Those are called “reverse polarity” fuses, designed to blow if the power is connected wrong at the battery.

Since yours seemed to be ok for a bit, I would start at the battery. If you have any doubts about its age, or previous care replace it. Get a Deep Cycle battery. Once you have that figured out get 2 20A fuses and try again. Using a volt meter test at the battery while plugged into shore power, you should see 13VDC.

Post back with your results and we will try to get you out camping on time.

@chuckster57 thank you for responding. It's funny because I did say to my husband every picture that I looked at showed 40 amp fuses in the reverse polarity section. When we pulled out the 2 20 amps they were both blown. My husband put two new ones in and everything seems to be working now. However we haven't really used anything yet because we don't go camping until next week. So I think what happened is exactly what you said, they ran it off the battery while we were looking at it when we got home, we used whatever was left in the battery and when the battery died it tried to switch over to our house and that's when the fuses blew. So my husband is going to look at it today to figure out which converter is ours and I will post on here what the end result is. Thank you again!

[Dd48]

Originally Posted by flybouy

I would see if you can find the model number on the converter to verify the fuse size. From your description it sounds like they are the reverse polarity fuses that provide protection to the converter in the event of the battery being connected incorrectly. 20 Amp sounds too light to me.

You bought a 10 yr old camper so I would get that battery checked out by taking it to a battery retailer that can load test the battery. Many auto parts stores that sell batteries offer this service free of charge.

You say "all the lights were still on" would have me guessing that the battery of unknown age and condition was drained and "all the lights" (most likely incandescent) finished it off. The PO (previous owner) may have blown the fuses connecting the battery and just used what they had to get it sold.

While you're having that battery tested do yourself a HUGE FAVOR and check the tires for manufactured dates, air pressure, and who made them. Trailer tires usually rot before they wear out. Depending on tire manufacturer they should be replaced by year five, some before that. A 10 yr old unit should be at least on it's second set of tires with a third set due or over due.

@flybuoy. Hi, thank you for the reply. As I stated above thanks to your guys's responses my husband is going to look into it, and get the right model number of our converter and make the necessary changes, and then I will post the end result on here! Wish us luck!

[Dd48]

Originally Posted by ChuckS

https://wfcoelectronics.com/wp-conte...Manual-web.pdf

page 4 will tell you exactly what size reverse polarity fuses are required for your converter... if this is the 55 amp board then 40 amp fuses are what is called for... your converter is an 8900 series and most likely the 8955 but you can look at the converter located down in the power panel and get the model number to be certain

@ChuckS. Thank you for the downloadable manual. I did look at other manuals and I don't recall seeing this in there LOL. However we're going to definitely take a look at the converter panel and make the necessary adjustments and then I will post on here how we made out. Thanks again!

[JRTJH]

The 2010 Outback brochure lists that all models have a 55 amp converter. Your trailer is a 30 amp "shore power system" so the WFCO converter in your trailer is a WFCO 8955 (unless a previous owner has replaced it with a different brand/size)... https://www.keystonerv.com/media/2458/outback-2010.pdf

The WFCO 8900 series manual recommends two 40 amp fuses for reverse polarity protection in the 8955 converter: https://wfcoelectronics.com/wp-conte...Manual-web.pdf

The only converters using 20 amp reverse polarity fuse protection are the 8965/8975 series... They require FOUR 20 amp fuses. All others, with TWO fuses use either 30 amp or 40 amp fuses.... If you have "two fuse slots" then 20 amp fuses are not the correct ones.

[Dd48]

Originally Posted by JRTJH

The 2010 Outback brochure lists that all models have a 55 amp converter. Your trailer is a 30 amp "shore power system" so the WFCO converter in your trailer is a WFCO 8955 (unless a previous owner has replaced it with a different brand/size)... https://www.keystonerv.com/media/2458/outback-2010.pdf

The WFCO 8900 series manual recommends two 40 amp fuses for reverse polarity protection in the 8955 converter: https://wfcoelectronics.com/wp-conte...Manual-web.pdf

The only converters using 20 amp reverse polarity fuse protection are the 8965/8975 series... They require FOUR 20 amp fuses. All others, with TWO fuses use either 30 amp or 40 amp fuses.... If you have "two fuse slots" then 20 amp fuses are not the correct ones.

Hi, so after I was reading everybody else's responses we went back into the trailer and upon reading the converter where all the fuses are listed it lists for fuses 10 and 11 that they are 30 amp fuses not 40 amp fuses. so I think we are going to replace them with 30 amps and see what happens. Thank you for all of your information it is greatly appreciated!!!

[JRTJH]

Originally Posted by Dd48

Hi, so after I was reading everybody else's responses we went back into the trailer and upon reading the converter where all the fuses are listed it lists for fuses 10 and 11 that they are 30 amp fuses not 40 amp fuses. so I think we are going to replace them with 30 amps and see what happens. Thank you for all of your information it is greatly appreciated!!!

I think you may be confusing the reverse polarity fuses with the "electrical distribution fuses"....

ALL of the fuses in the vertical row are "electrical distribution fuses" and protect various DC circuits throughout the trailer. In most trailers, ALL of the vertically arranged fuses are 15 amps (blue) and the bottom two (probably labeled "10/11") are "higher amperage circuits"... They typically have either 20 amp or 30 amp fuses... You'll need to confirm the size of the wires attached to them to determine the ampacity fuse required...

The reverse polarity fuses are either located "just to the left of the vertical distribution panel" or if the converter is separate from the trailer power panel, they are located on the actual converter assembly. The reverse polarity fuses are NOT located in the row of vertical fuses and the bottom two fuses in that vertical row "probably are larger than 15 amp fuses....

[Dd48]

Originally Posted by JRTJH

I think you may be confusing the reverse polarity fuses with the "electrical distribution fuses"....

ALL of the fuses in the vertical row are "electrical distribution fuses" and protect various DC circuits throughout the trailer. In most trailers, ALL of the vertically arranged fuses are 15 amps (blue) and the bottom two (probably labeled "10/11") are "higher amperage circuits"... They typically have either 20 amp or 30 amp fuses... You'll need to confirm the size of the wires attached to them to determine the ampacity fuse required...

The reverse polarity fuses are either located "just to the left of the vertical distribution panel" or if the converter is separate from the trailer power panel, they are located on the actual converter assembly. The reverse polarity fuses are NOT located in the row of vertical fuses and the bottom two fuses in that vertical row "probably are larger than 15 amp fuses....

Yes the two fuses I was referring to are the two fuses to the left.