Furnace Fuse

[wyked]

i have a 2017 Forest River 30’ tt ... furnace is blowing fuses immediately upon replacing fuse. i’m not very familiar with hvac, or how the wiring in these things work, looking for some guidance with where/how to start with diagnosis.

so, furnace fuse blows, without furnace being on. as soon as i put in a fuse it blows. furnace has worked the last few weeks without issue.

TIA,

-Jeff

[2oldman]

Sounds like another quality job of installation. Glad you found it.

[enblethen]

Thanks for the update!

[wyked]

so, i thought i would post here to offer my findings for future reference ....

after accessing the furnace unit (below the oven) i quickly found the problem .... the wiring to the unit runs under the metal frame, between the trailer floor, the furnace’s metal frame, and some foam stripping ..... the metal frame had cut through the 2 wires (white/yellow) and were shorted directly to the furnace unit. i lifted the furnace unit, used an old rubber keychain thing to put between the furnace frame & the wiring, and we’re good as new!!

thank you all for the input!!!

[enblethen]

Should have owner's manual packet that has furnace info.
If you do not have complete packet, I would go through your rig making list of appliances. Make and model numbers along with serial numbers.
Remember that things fail at night when it is cold and raining!

[wyked]

enblethen wrote:
What is the make and model of your furnace?
Doug is correct to try to isolate the issue by disconnecting the 12 volt power at furnace.

not sure the make/model, and honestly, i’m not even 100% sure i know where it is, but i’ve got a good idea. i’ll be diving into it soon ... thank you all, i’ll be back if i have any further questions.

-Jeff

[enblethen]

What is the make and model of your furnace?
Doug is correct to try to isolate the issue by disconnecting the 12 volt power at furnace.

[dougrainer]

With the wall tstat OFF, the furnace fuse blows? Regardless, you will have to access the 4 wires TO the furnace and the furnace itself. The FIRST thing you do, is, disconnect the 12 volt positive feed wire at the furnace. Replace the fuse, IF it blows, then the problem is between the fuse center and the furnace. If it does NOT blow, the problem is internal to the furnace and the furnace will have to be pulled if your model is not mounted from the outside wall. Doug

[newman_fulltime]

Hot wire came loose at the furnace and is shorting out