Furnace blowing fuses

[REDBEV MONTANA]

Furnace keeps blowing fuse but not constant. May last 6-7 days may last 1 day. Curious if anyone else having same problem. Hard to figure out as it not constant. 2016 Montana 3720

[Ozz]

My guess from very limited information is that the motor is getting tight, or just going bad
You could amp it; measure the amp draw, but it being 'on occasion' that may not give good info.
I would pick one up if you intend on changing it when it goes, good to have one on hand in case.
Good luck to you.

[WeBeFulltime]

2016 Monty should be under warranty.

[DQDick]

Call Keystone Customer Service and at the very least get a file started on it.

[Rondo]

As Dave and Dick have said-- since it is a 2016 first contact Keystone Customer Service to get a file and file # started, then take you unit to or contact your dealer and see what they say. Since it is under warranty you should have no expense on the repair or for them to solve the problem. Since Ozz is a heating and air specialist he should know what the problem is and is really good at diagnosing things when it comes to this type of problem. Remember to call Keystone Customer Service before contacting your dealer or if you are on the road a dealer near you authorized to work on your rig. Keystone MAY authorize an outside service tech not connected with a dealer to work on it also but that is up to them. Also if and when you take it to a dealer make sure they know you have gotten a file started on the problem. Also when calling Customer Service be sure to have your VIN # as well as date of purchase available to give to them. It will take less time with those two items for sure.

[Ozz]

Sorry, did not read your post well. By all means contact your dealer/keystone
Good luck

[Ozz]

Since it is new, my money would be on a loose connection on the fuse panel. When mine was new I pulled both panels and some on each panel could have been pulled out of the connectors without tools. The worst I have ever seen. I tightened all of them and had to replace some of the crimp connectors. The loose connections would give you the symptoms you are having.
Connections could be loose at the board in the furnace as well.
If you feel comfortable pulling the L.V. panel and checking connections, it might be worth your time.

[REDBEV MONTANA]

Thanks for all the info. It is under warranty but if it is something simple I can take care of it's economically better to me as our dealer is a ways a way. I will check out the connections and see what I find.

[REDBEV MONTANA]

Checked all connections all seem fine, motor turns freely by hand. Guess I will have to make arrangements to take into dealer although I'm leery of what they will be able to come up with as it is so random. Anyone have any thoughts or experience replacing fuse with circuit breaker? Or is that a no no? I know it is pretty common for big rig owners to replace factory fuses with replacement circuit breakers.

[DQDick]

I believe you have both. A fuse for the 12v controls and a breaker for the 110v power to the fan motor. If so and it's the fuse that's blowing you may have an occasional circuit board problem.

[Irlpguy]

Knowing the way the wiring is done in these Montana's I would be curious to know if somehow there is something else on the same circuit as the furnace, which occasionally overloads the fuse. The furnace fan is also 12V rather than 110V as suggested by DQDick so the furnace runs entirely on 12V supplied either by the batteries or the Converter.
Wires have been known to have had screws and or staples put through them during construction which could cause a short that is not evident at all times but occurs with movement of the affected wire.
There is such a mess of wiring behind the wall of the basement but you may have to investigate that area for a possible problem.
Powering the furnace directly from the battery with a fused wire would determine if there is a problem somewhere between the converter fuse panel and the furnace.

Good luck with the investigation.

[DQDick]

Sorry, Ed's exactly right. Shouldn't try to answer and watch football at the same time.

[wagal64]

quote:Originally posted by REDBEV MONTANA

Furnace keeps blowing fuse but not constant. May last 6-7 days may last 1 day. Curious if anyone else having same problem. Hard to figure out as it not constant. 2016 Montana 3720

We have the very same problem with 2016 Montana 3911fb. I have been told by dealer that this is a new type furnace system and they believe water is getting through vent cover and damaging circuit board. They have several circuit board fixes on order and are supposed to receive them this week so I should know soon if this will solve the problem. Ours only blows the 12v fuse and not the breaker. It does not blow immediately, but at various intervals just as yours does.

[REDBEV MONTANA]

Very interesting, sounds like the same problem. Will be waiting to hear if that fixes yours as I,m not going to take into dealer till after all the holidays. Thanks for info.

[WeBeFulltime]

quote:Originally posted by wagal64

We have the very same problem with 2016 Montana 3911fb. I have been told by dealer that this is a new type furnace system and they believe water is getting through vent cover and damaging circuit board. They have several circuit board fixes on order and are supposed to receive them this week so I should know soon if this will solve the problem. Ours only blows the 12v fuse and not the breaker. It does not blow immediately, but at various intervals just as yours does.

Yours doesn't trip a breaker because there is no AC power to the furnace. Furnace operates only on 12v power.

[Ozz]

Good post Ed, I think you suggestions have great merit. I my 45 years of troubleshooting, I have seen this kind of problem/solution
Better the RV owner troubleshoot it than an overworked, rushed dealer tech.
A guy could string a new thermostat control wire if he or she felt like and could do it.

[wagal64]

quote:Originally posted by wagal64

We have the very same problem with 2016 Montana 3911fb. I have been told by dealer that this is a new type furnace system and they believe water is getting through vent cover and damaging circuit board. They have several circuit board fixes on order and are supposed to receive them this week so I should know soon if this will solve the problem. Ours only blows the 12v fuse and not the breaker. It does not blow immediately, but at various intervals just as yours does.

Update on this post. My problem turned out to be a faulty blower motor. It has been replaced and seems to be working fine.

[Art-n-Marge]

THAT could cause the intermittency for the problem you were having. I hope that was a warranty repair!

I hope things will keep working for you.

[Lawdogs]

My 3721RL is at the dealer right now for the same issue. It started out blowing the fuse while on the auto set. Now it is blowing at start up in all settings. It is being handled under the dearship's 90 day warranty. Will report back when I find out what they had to do to effect repairs

[Lawdogs]

Just heard from the Service Manager. He said the blower motor needs to be replaced. Possibly two weeks to get the part due to holidays. So much for camping over Christmas. Hope to have it back in time to camp over New Years!!!