Zinger Lite ZR18BH Fuse #6 question

[vtirocz]

Hi,
I have a 2019 Zinger Lite 18BH model and have an issue where Fuse #6 seems to blow fairly often with no accessories in the RV on. I notice it after I unplug the camper from 110V household outlet and try to use accessories off battery power. I troubleshoot and always find Fuse #6 to be blown. This has happened 3 times in the last 6 months. Camping World did some troubleshooting on it since it's under warranty and simply replaced the fuse with a 15amp fuse (I'm assuming that's what it was built with?).

I reached out to Keystone RV directly and this was their response - they say it should be a 30amp fuse, but to confirm with the selling dealership (not sure why the selling dealership would need to verify what the design is supposed to be??):

" I believe that circuit 6 is the recharge line and I’m showing it’s a 30AMP. Are there spots for 2 fuses at 15amps. If not then I’m not sure why there is a 15 in the 30. I’d recommend to contact the selling dealership on that. I don’t want you to get yourself in to trouble if the information we have on our side is wrong. It may have been changed in production and not updated on our end.

Please do follow up on the inquiry with your selling dealership."

One additional piece of information: I believe the issue I'm having is identical to what's documented in this TSB (not for my model), where Fuse #6 was shipped out from the factory with a 15amp fuse instead of 30amp fuse: https://static.nhtsa.gov/odi/tsbs/2015/SB-10057855-3763.pdf

QUESTION: Is a 15 amp fuse the correct rating for fuse #6? If others have this model (or similar), could you please confirm? It seems small to me, but that's what it came with. On the circuit board itself (see picture) it says "F5&F6 Position; Max. Rating: 30 amp; For Battery and Slide Out Used". I suspect simply swapping in a 30amp fuse would fix the problem, but want a concrete answer that the circuit was designed for that since it's really the minimum gauge wire in the circuit that matters, which I don't have visibility of.

Thanks in advance!!

[JRTJH]

First, there is no "assurance" that the worker who wired your trailer connected the wiring in the same sequence/position as the trailer produced before or after it. The circuit attached to fuse position #6 in your trailer "may or may not" be the same circuit connected to that fuse in any other trailer. THAT'S WHY KEYSTONE TOLD YOU TO HAVE THE DEALER CONFIRM WHAT THEY TOLD YOU.

If you are unsure of working with electricity then you need to take it back to the dealership and tell them that their "previous fix" did not resolve the problem....

If you are familiar with working with wiring, then unplug the trailer from shore power, disconnect the battery/batteries and remove the power center from its mounting location. The wiring is long enough for it to pull away from the space and you will have access to the area behind it. With the power center removed, you can then disassemble the face plate and actually "see the wire attached to fuse #6. You can follow that wire out of the power center to confirm that it does not "change color, change size or branch to multiple wires"... If it appears to be the same wire, you can confirm that it connects to the battery with a multimeter. Your suspicion that it's the charge line may be correct. If so, and if the wiring is sufficient size, then you can install a larger fuse. You may also consider a "DC circuit breaker" for that fuse position. You can find them at any auto parts store. If you install a 15 amp "auto-reset breaker" it will trip, but will automatically reset when cool. With the issue having "occurred 3 times in 6 months" it's apparently is not a "frequent" or "every time I turn on the switch" type of event.

I'd be cautious about increasing the size of the fuse to "double the rating" without positively knowing what is wired to that fuse position. You may create a hazard if the wiring splits or branches to another circuit that you're not aware is connected and that branch changes to a much smaller gauge wire.

As for "building them all exactly the same, don't count on that happening. Your trailer is not a "automated line product", it was built individually by people who "change things up to fit the build in the most expeditious manner. One may have fuse #6 on the charge circuit and the next one down the line may have fuse #5 on the charge circuit.

All of the WFCO power center "DC fuses panels" are standardized with two fuse positions providing 30 amp fusing capacity. That does not mean Keystone wired those two fuse positions with wiring that's capable of carrying that much current.

[flybouy]

I confused by some of your descriptions. You didn't say what amperage fuse was in it when it "blew". You say you were told it was the "recharge" do you mean the battery charging circuit"? If that's the case I'd think it would blow when connecting to shore power and not after it's unplugged from shore power.

Do you have any experience working on electrical low voltage wiring/circuits? Do you have/know how to use a VOM? If the answer is no then stop and take it back to the dealer.

To John's point, the common misconception to new owners is that trailers are built like motorized vehicles where the wiring is in a "Loom" and can only go one way, the same way every time. In fact, it's more like your house. The electrical distribution panel in your house may be the same size and brand as your neighbor but your dishwasher may be on breaker #3 and theirs is on #7. Similar to your house electrical distribution panel the only "absolutes" is where the supply gets connected on the 120vac side. The distribution can go anywhere givon the proper breaker/wire size is used. On the 12vdc side the 12vdc leaving the converter and the battery supplies the fuse bank. The capacity of those fused circuits are restricted to the size of the fuse holder and the wire size leaving it. So point being, if fuses 1 thru 7 are capable of transferring 15 amps each then the installer can connect any circuit up to a 15 Amp load to any of those fuses.

[vtirocz]

First, there is no "assurance" that the worker who wired your trailer connected the wiring in the same sequence/position as the trailer produced before or after it. The circuit attached to fuse position #6 in your trailer "may or may not" be the same circuit connected to that fuse in any other trailer. THAT'S WHY KEYSTONE TOLD YOU TO HAVE THE DEALER CONFIRM WHAT THEY TOLD YOU.

If you are unsure of working with electricity then you need to take it back to the dealership and tell them that their "previous fix" did not resolve the problem....

If you are familiar with working with wiring, then unplug the trailer from shore power, disconnect the battery/batteries and remove the power center from its mounting location. The wiring is long enough for it to pull away from the space and you will have access to the area behind it. With the power center removed, you can then disassemble the face plate and actually "see the wire attached to fuse #6. You can follow that wire out of the power center to confirm that it does not "change color, change size or branch to multiple wires"... If it appears to be the same wire, you can confirm that it connects to the battery with a multimeter. Your suspicion that it's the charge line may be correct. If so, and if the wiring is sufficient size, then you can install a larger fuse. You may also consider a "DC circuit breaker" for that fuse position. You can find them at any auto parts store. If you install a 15 amp "auto-reset breaker" it will trip, but will automatically reset when cool. With the issue having "occurred 3 times in 6 months" it's apparently is not a "frequent" or "every time I turn on the switch" type of event.

I'd be cautious about increasing the size of the fuse to "double the rating" without positively knowing what is wired to that fuse position. You may create a hazard if the wiring splits or branches to another circuit that you're not aware is connected and that branch changes to a much smaller gauge wire.

As for "building them all exactly the same, don't count on that happening. Your trailer is not a "automated line product", it was built individually by people who "change things up to fit the build in the most expeditious manner. One may have fuse #6 on the charge circuit and the next one down the line may have fuse #5 on the charge circuit.

All of the WFCO power center "DC fuses panels" are standardized with two fuse positions providing 30 amp fusing capacity. That does not mean Keystone wired those two fuse positions with wiring that's capable of carrying that much current.

Thanks for that detailed feedback! I appreciate it. I think I'll need to do exactly as you suggested and trace the wiring to determine what exactly circuit 6 is wired to and the gauge of that wiring.

Regarding not every Zinger Lite ZR18BH being identical, I agree with that somewhat, but would also point out that they must be working to some design spec. I doubt they are creating a "one off build" for the circuitry for each ZR18BH coming down the line. If they were truly one off builds, then how could Keystone have a TSB covering 800 serial #s, where they identified the wrong fuse was used for a specific circuit? With that said, I'd be interested to understand how other ZR18BH's were built, but your point is well taken that there could be some variation among builds, so it's best to check the wiring on my specific trailer.

I confused by some of your descriptions. You didn't say what amperage fuse was in it when it "blew". You say you were told it was the "recharge" do you mean the battery charging circuit"? If that's the case I'd think it would blow when connecting to shore power and not after it's unplugged from shore power.

Do you have any experience working on electrical low voltage wiring/circuits? Do you have/know how to use a VOM? If the answer is no then stop and take it back to the dealer.

To John's point, the common misconception to new owners is that trailers are built like motorized vehicles where the wiring is in a "Loom" and can only go one way, the same way every time. In fact, it's more like your house. The electrical distribution panel in your house may be the same size and brand as your neighbor but your dishwasher may be on breaker #3 and theirs is on #7. Similar to your house electrical distribution panel the only "absolutes" is where the supply gets connected on the 120vac side. The distribution can go anywhere givon the proper breaker/wire size is used. On the 12vdc side the 12vdc leaving the converter and the battery supplies the fuse bank. The capacity of those fused circuits are restricted to the size of the fuse holder and the wire size leaving it. So point being, if fuses 1 thru 7 are capable of transferring 15 amps each then the installer can connect any circuit up to a 15 Amp load to any of those fuses.

Thanks for that feedback. It had a 15 Amp fuse in it when it blew. What I said (or at least what I was trying to communicate) is that I notice it when I unplug shore power, but that just means that the fuse blew some time between plugging it in and when it was unplugged. The symptoms are none of the lights, outlets, electrical devices work in the RV off battery power with fuse 6 blown. While plugged in, everything's fine and there's not obvious symptoms - hence why noticing the problem only when unplugged and trying to operate off battery power.

I copied the direct quote from Keystone regarding what Fuse 6 does (ie "recharge line") and I'm interpreting their response the same way in that it's for recharging the battery.

I'll plan to dig into this a bit more and will report back.

[hankpage]

QUOTE: Fuse #6 seems to blow fairly often with no accessories in the RV on. I notice it after I unplug the camper from 110V household outlet and try to use accessories off battery power. I troubleshoot and always find Fuse #6 to be blown. This has happened 3 times in the last 6 months.

Does your trailer have slide outs or other high draw DC motors????? If so,
are these the "accessories" you are talking about???? Slides and electric jacks should be operated while still connected to shore power or you running Tow Vehicle. (Disconnecting external power source causes voltage drop. Voltage drop causes amperage rise.) So if these motors are working while on shore or TV power and blowing #6 when external power is removed this may be your problem. Operate slide out while on shore power, remove fuse #6 and see if slide still works, verify that fuse is not blown, replace fuse and move slide (or jacks) again. Slides are usually connected to their own DC circuit breaker but in this case who knows. Since it is under warranty let the dealer fix it. (Replacing the fuse and testing it while on their shore power is not repairing it. ) JM2¢. hope I did not confuse you, Hank

[vtirocz]

I determined that Fuse 6 basically runs straight to the positive terminal on the battery - see pictures below with some explanation.

Picture 1: 10 AWG (pink) wire is the one that goes to Fuse 6.

Picture 2: 10 AWG (pink) wire is connected directly to red positive battery cable (which runs to front of trailer to battery)

Picture 3: Red battery cable runs all the way to the front of the trailer with no interruptions except to this 50 amp shortstop breaker - then from there directly to the positive terminal on the battery.

So with that said, does a 30 amp fuse seem appropriate for the Fuse #6 slot? I think this all confirms the Keystone RV tech support rep was accurate with their schematic showing a 30 amp fuse. Would appreciate input.

[flybouy]

Thanks for that detailed feedback! I appreciate it. I think I'll need to do exactly as you suggested and trace the wiring to determine what exactly circuit 6 is wired to and the gauge of that wiring.

Regarding not every Zinger Lite ZR18BH being identical, I agree with that somewhat, but would also point out that they must be working to some design spec. I doubt they are creating a "one off build" for the circuitry for each ZR18BH coming down the line. If they were truly one off builds, then how could Keystone have a TSB covering 800 serial #s, where they identified the wrong fuse was used for a specific circuit? With that said, I'd be interested to understand how other ZR18BH's were built, but your point is well taken that there could be some variation among builds, so it's best to check the wiring on my specific trailer.



Thanks for that feedback. It had a 15 Amp fuse in it when it blew. What I said (or at least what I was trying to communicate) is that I notice it when I unplug shore power, but that just means that the fuse blew some time between plugging it in and when it was unplugged. The symptoms are none of the lights, outlets, electrical devices work in the RV off battery power with fuse 6 blown. While plugged in, everything's fine and there's not obvious symptoms - hence why noticing the problem only when unplugged and trying to operate off battery power.

I copied the direct quote from Keystone regarding what Fuse 6 does (ie "recharge line") and I'm interpreting their response the same way in that it's for recharging the battery.

I'll plan to dig into this a bit more and will report back.

Just trying to get clarity. What "outlets" and "appliances" are not working when shore power is disconnected? The household type outlets only operate on 120vac as well as the microwave, the electric setting on the fridge and water heater as well as the television.

[vtirocz]

Just trying to get clarity. What "outlets" and "appliances" are not working when shore power is disconnected? The household type outlets only operate on 120vac as well as the microwave, the electric setting on the fridge and water heater as well as the television.

I misspoke there - I should have stated that just the lights (all lights), water pump, indicator panel (water level, gray tank level, black tank level, battery level) are all dead when not connected to shore power.

See post above for some additional clarification on wiring connected to fuse 6.

[flybouy]

I misspoke there - I should have stated that just the lights (all lights), water pump, indicator panel (water level, gray tank level, black tank level, battery level) are all dead when not connected to shore power.

See post above for some additional clarification on wiring connected to fuse 6.

I think we were typing at the same time as your post with pics wasn't there when I started. From what you have posted I'd agree that the fuse/circuit is most likely wired correctly for the converter to charge the battery. I'd replace with a 30 Amp fuse and keep an eye on it.

[hankpage]

I determined that Fuse 6 basically runs straight to the positive terminal on the battery - see pictures below with some explanation.

Picture 1: 10 AWG (pink) wire is the one that goes to Fuse 6.

Picture 2: 10 AWG (pink) wire is connected directly to red positive battery cable (which runs to front of trailer to battery)

Picture 3: Red battery cable runs all the way to the front of the trailer with no interruptions except to this 50 amp shortstop breaker - then from there directly to the positive terminal on the battery.

So with that said, does a 30 amp fuse seem appropriate for the Fuse #6 slot? I think this all confirms the Keystone RV tech support rep was accurate with their schematic showing a 30 amp fuse. Would appreciate input.

If these were MY findings after MY trace of the wires I would agree with the Keystone tech and install a 30amp fuse in #6. YMMV, Hank

[vtirocz]

I think we were typing at the same time as your post with pics wasn't there when I started. From what you have posted I'd agree that the fuse/circuit is most likely wired correctly for the converter to charge the battery. I'd replace with a 30 Amp fuse and keep an eye on it.

If these were MY findings after MY trace of the wires I would agree with the Keystone tech and install a 30amp fuse in #6. YMMV, Hank

Thanks very much for taking the time to provide that input!! Much appreciated! I'll replace Fuse #6 with a 30amp fuse and monitor. Is there anything specific I should be on the look-out for other than visually inspecting the wiring after some time?

hankpage, just FYI in response to your prior post, the Zinger Lite ZR18BH is essentially a "base" model with no slide-out option.

[hankpage]

hankpage, just FYI in response to your prior post, the Zinger Lite ZR18BH is essentially a "base" model with no slide-out option.

Yep! After I posted I took the time to look it up but I type so slowly that several posts had gone in before mine.
https://www.keystoneforums.com/forums/picture.php?albumid=251&pictureid=1587 You have to make allowances for old farts like me.

[vtirocz]

Just reporting back on this one: I've had the fix (30amp fuse in Fuse #6 slot) for 2 weeks now including a 4 day camping trip and plugging/unplugging numerous times in the driveway. The issue appears to be fixed. Thanks again for the feedback!