No Battery Power

[SCGatl]

Hi again, another issue. When I bought my 175LHS, I picked it up and took it directly to storage. Now I have it in my driveway to flush the water system etc., and everything seems to work (except the fridge, propane only?) while connected to house power.

Once disconnected from shore power, I get nothing - no lights, no pump, nada. So I went out and bought a brand new Duracell deep cycle battery, installed it and reconnected to shore power for a few hours. Same thing - disconnect power from house, no lights or water pump.

While plugged in, I'm getting 12.5v at the battery, and anywhere from 12.5v - 13.6v at each of the contact points next to each DC fuse.

When unplugged, nothing at all on the contacts. Is there a hidden switch or something simple that will make me feel happy and dumb at the same time?

Thanks all,
Steve

[Johnny's Journey]

Did you test the reverse polity fuses that protect against accidental crossing of the battery cables.

[SCGatl]

Hi Johnny - that was it. I checked them all visually, but used an ohm meter to be sure, and sho'nuff, that one is wide open. BTW the short queen mattress from Zinus (10" Spring) is very comfortable...I will sleep like a baby at hunt camp.

[Johnny's Journey]

Excellent :)

[Johnny's Journey]

used an ohm meter to be sureSteve why did this test yield a different conclusion versus taking the voltage reading off the fuses ? Clue "12.5v - 13.6v"

[KennyDean]

Hello I am having the same problem after feeling my water tank only the microwave tv and sockets work nothing else. Where do I find the reverse fuse at. Newbie thank you

[Johnny's Journey]

Where do I find the reverse fuse at.Inside of one of these. http://www.rvpartscountry.com/-Power-Inverter-Door-WFCO-Converters-Plastic-Portion-Only_p_27303.html

[KennyDean]

Thank you ok what am I looking for? Buddy I am a wounded vet with a brain injury sorry to ask you these types of questions

[Johnny's Journey]

No worries. Push on the door and when opened you'll see automotive type fuses. Look for the higher amp fuses that should say 40. You'll also see next to it what it protects.

[SCGatl]

Johnny, the test point must have been before the fuse, where the inverter is powering the supply side. Assuming I didn't see the the load side.

Kenny, the fuses are automotive style - you can just pull them out with your fingers. If you hold them up to a window or light, you should see if the two sides are connected with a thin wire in the middle. If it is open, not connected, the fuse has blown.

[chuckster57]

Johnny, the test point must have been before the fuse, where the inverter is powering the supply side. Assuming I didn't see the the load side.

Kenny, the fuses are automotive style - you can just pull them out with your fingers. If you hold them up to a window or light, you should see if the two sides are connected with a thin wire in the middle. If it is open, not connected, the fuse has blown.

I'm sure you meant CONVERTER, inverters turn 12VDC into 120VAC and converters turn 120VAC into 12VDC. When plugged into shore power the converter supply's 12VDC power to the coach and charges the battery(s).

[SCGatl]

You are correct Chuck, thanks for clarifying.

[Johnny's Journey]

test point must have been before the fuse...... Assuming I didn't see the the load side. Right there, you said you had a voltage reading at both ends of each fuse on post 1 and that's where the confusion came in. Based on how you wrote your question I have to assume you had the trailer on shore power and the battery/ies connected. This is will give anyone a reading on the line side and the load side of the fuse but it was from 2 different sources because the fuse was blown. Conclusion ? Perform test with only one power source while doing test for voltage.

[SCGatl]

http:///Users/stepheng/Desktop/IMG_2144.JPG

I checked on the pins to the right of the fuses with shore power connected, with the negative meter probe on chassis ground. Hope the pic appears.

[Johnny's Journey]

Awesome. Does this mean both sides of the fuse were or were not tested ? Sorry no pic came thru and that's OK.

[SCGatl]

Hi Johnny - correct, only one side of the fuse was tested with power. There was nothing I could easily see to get a probe onto for the other side, which I assume was the load side.

[Johnny's Journey]

OK cool. The important thing is it's fixed now and your ready to enjoy again. :)

[SCGatl]

OK, so after replacing the 15A fuse and all being well, I went out this morning and the fuse was blown again. I have not touched the battery - I left the trailer disconnected from shore power for a few days just to see how well my new batter would hold a charge.

I had also connected my Honda eu2000 genny to test it out, and once I realized there was an On-Off lever on the genny gas cap for venting, it handled the AC unit just fine. (thru the wall unit)

What possible causes are there of this fuse blowing?

Thanks All!

[chuckster57]

You need to determine what is on that 15A circuit. Don't trust the labels, just pull the fuse and start turning everything 12V on and see what doesn't work. That included the water heater on LP, the furnace and refer on LP. Often overlooked is the LP detector.
Once you know what's on that circuit you can start turning things back on with the fuse in. I use a tool like this:
https://m.harborfreight.com/30-amp-automotive-fuse-circuit-tester-67724.html
As it will display load as you turn stuff on. Great for identifying what component is causing the issue. If the LP detector is on that circuit, you can cut the power wire before starting, and add it last. Had a new unit a few months ago that had the LP detector have an internal short.

[SCGatl]

Thanks, I will pick up one of those meters. I have not ran the hot water heater nor the fridge as of yet. The LP detector is on that circuit - green light is on when I have DC power. So far i know the inside lights (All LED), water pump, tank/battery level panel are on that circuit. But, only the tank/battery level panel and the Atwood LP detector would have been on when the fuse blew. Heading out of town for a few days, so will check over the weekend.

[SCGatl]

OK, so 175LHS is now down at hunt camp, and the fust problem continues. It is not the polarity fuse, it is the one right above it.

Nothing is labeled in my panel. All are 15A except the bottom one.

Here is what is happening:

Generator runs out of gas while AC is running. Fuse blows.
Generator runs out of gas while nothing is running. Fuse blows.
Generator is shut off while nothing is running. Fuse blows.
Disconnect from shore power while nothing is running. Fuse blows.

Used power meter suggested above - only thing that I can tell is on that circuit is the CO2 sensor at 0.2A.

When inserting new fuse, terminals spark. Once fuse is in, the fan in the converter/inverter runs for about 15 seconds, then stops. Everything good again until switching from AC to battery power. When the fuse is blown, nothing DC works.

I also don't feel the battery is being charged, after running the generator for 12 hours, the battery meter (stock) shows 75%.

Thanks for any help! What would be wrong with the converter? It can't handle the cutover from AC to DC.

Steve

[JRTJH]

What brand/model converter is installed in your trailer? I'd suspect it's a WFCO 8955. That is a 30 amp (AC power) center (30 amp shore power input) with a WFCO 55 amp (DC) converter/fuse panel. Is that correct? If so, then there are two "reverse polarity fuses, one above the other. Both are the same amperage (in my trailer they are 40 amp fuses). From your statement: "It is not the polarity fuse, it is the one right above it." it sounds like someone may have installed an incorrect fuse in your converter's reverse polarity circuit.

At any rate, the two reverse polarity fuses "should be" the same amperage, probably 40 amps and even though the other fuse positions are rated "up to 20 amps" the vast majority of Keystone's wiring only supports 15 amps, and that's what you'll find in the fuse positions.

As for your statements, I'll address each one with a comment:
Generator runs out of gas while AC is running. Fuse blows. (the AC running has nothing to do with 12 VDC power except the single wire that powers the thermostat, so there should be no DC power fluctuation and no fuse "should blow")
Generator runs out of gas while nothing is running. Fuse blows. (In this situation, even the thermostat 12 volt power would not be powered, so there's nothing that's 12 VDC operational that would "load a DC circuit")
Generator is shut off while nothing is running. Fuse blows. (again, with nothing running, there should be no DC power and no load on any fuse)
Disconnect from shore power while nothing is running. Fuse blows. (Same response, same result, there should be no DC load)

I guess my final question (or uncertainty) is "Exactly which fuse is blowing?" If it's the top reverse polarity fuse, and it's not a 40 amp fuse, then I'd suspect that someone installed the incorrect fuse. If that's not the fuse that is blowing, then which one is it?????

EDIT: Added: Upon looking at your trailer model, you don't have a "wall mounted thermostat" for the air conditioner. It is (I believe) a "through the wall" window unit installed in the sidewall of your trailer. If that's correct, then there is no 12 VDC power to the thermostat in your A/C system. So, in your "list of conditions" the Air conditioner operational status would not affect the thermostat power, so any 12 VDC fuse loading would not be affected by the air conditioner power whether it's off or on when removing shore power/generator power from the trailer.

[SCGatl]

Thanks,

You are right it is a through the wall unit, no thermostat. The unit is a WFCO ULTRA III Power Center.

My trailer is about 130 miles away at the moment, so all I know for sure is that it is the next one up from the bottom that is blowing.

I agree nothing should be causing the fuse to blow with no load - what would cause this to consistently occur when disconnecting AC power from either a generator or shore power?

[SCGatl]

Model is either WF-8735P or WF-8740P....manual does not state fuse ratings or much else of use :)

[JRTJH]

The owner's manual for the 8700 series power centers show a total of 8 DC fuse slots. The top 6 are for "DC circuits" the bottom two (plural) are for Reverse Polarity. According to the data in the owner's manual, the top 4 are max 20 amp circuits, slots 5 & 6 are max 30 amp (for slides, etc) and then the bottom two (again plural) are the reverse polarity fuses.

You can download the owner's manual here: http://wfcoelectronics.com/wp-content/uploads/2017/01/8735-40-Operators-Manual.pdf

Based on what you're describing, I still suspect that you've got a "too small" fuse in the top Reverse polarity socket. Both of those should be the same rating.

Once you get back to the trailer, possibly you can take some pictures of what is actually installed so we can see the fuses and ratings? That may help identify something that's "not quite right"....

[SCGatl]

Since the fuse had blown when I left, and I had connected the generator upon arrival this past weekend, I put a 30A fuse in place before turning off anything running (except CO2 monitor) and turned the generator off.

I had DC power, so the 30A did not blow when I turned off the generator. Panel pics attached.

[B-O-B'03]

I believe both of the reverse polarity fuses should be 40 amp. It looks like you have a 30 and a 40.

I would replace the 30 with a 40.

-Brian

[hankpage]

The way I am reading the manual and the labels in your photos .... you have only one reverse polarity fuse (40amp) one 30amp for slide-out fuse and five 15amp circuits for accessories. If you are operating the slide with a low battery or without shore power the 30amp might blow. (low voltage = high amp draw)
Is the slide being moved when the fuse is blowing??? Has anything else been added to this circuit??? Check the wiring in junction boxes that feed the slide for frayed or pulled out wires ... they may be shorting with movement in trailer and blowing the fuse. As usual JM2¢, Hank
Be sure that battery and shore (or gen) power are disconnected before inspecting junctions and connections.

[SCGatl]

Hi BOB03 - there was a 15 in it when I got it, and I had stepped up to a 20 which also blew, and now a 30 which so far hasn't but only after one time of turning the generator off. I don't know anything about these units, but am wondering what is causing an amperage spike that would blow a 20A fuse in the first place. With nothing on, I don't get what is causing the current draw from the battery, or what would be allowing any capacitance to be occurring from disconnecting generator or shore 120v power.

[SCGatl]

Hi Hank - I don't have a slide in the 175LHS Hideout, nor is there anything at all turned on (except the CO2 sensor at 0.2A and microwave display) when this is happening.

[JRTJH]

I'd suggest a phone call to WFCO's technical support section. Here's why I suggest that: There are two different descriptions of the WFCO 8700 series 35 and 40 amp (8735/8740) models. On page 2 of the owner's manual, in the section about DC fuse protection, the manual states:
"DC Fuses
- Six 12 Vdc circuits (including one battery circuit, one circuit for slideouts)
- Maximum of 30 Adc fuse for DC circuits 5 and 6 (all others max. 20 Adc)
- Reverse battery protection fuse; replace with ATC “Littelfuse ” Type 257 fuse" (That's 7 fuse slots)

On page 4, figure 3 clearly shows 8 fuse slots (6 circuit slots and 2 reverse polarity slots)

So, either there's a problem with the description or there's a problem with the illustration. Both can't be correct. As Hank indicated a couple posts ago, it appears that you've got only one RP fuse slot, or is it possible that you used a camera angle that obscured the top fuse in the photo????

Something's not right, either in the photo you provided, in the illustration or the description in the owner's manual.

ADDED: Thinking about the problem and the application in your trailer, it seems to me that the fuse that's blowing is probably the one being used to connect to the battery. That would mean (if my assumption is correct) that the suspect fuse is controlling power during charging and discharging the battery. So, when you're connected to the generator/shore power that fuse is supplying amperage to the battery and as soon as the generator/shore power stops, that "amperage" reverses and starts flowing from the battery into the DC power section. So, a bad battery, either from a dead cell or from a shorted cell would cause an increased amp draw causing the fuse to blow.

I'd suggest you disconnect the battery (isolate it from the system) replace that fuse with a 15 amp (what was previously installed) and try to duplicate the problem by powering on the air conditioner and then turning off the generator. My guess is that the fuse won't blow. If so, then I'd suspect the battery and go from there by troubleshooting the battery, not the power center..... This is just a hunch, I'd still suggest you confirm from WFCO just why their owner's manual has two different depictions of how many fuses are in that model...... Something's not right with the manual and/or the way it's described and how it's built......

[SCGatl]

Thanks, I will call them - the model I have is WF-8735-P, and the pic isn't the best. It is not well illuminated, I will get a better picture next time I am at camp. To the best of my knowledge there are 7 slots. Here is a zoomed and cropped pic of the previous one. Can't read the small print on the board..

[SCGatl]

Tech confirmed that the 6th slot should be a 30A fuse, so the hand writing on the cover is wrong, and I will give it some time to make sure there isn't anything else going on.

I truly appreciate all of the replies, this is a great group!

Steve