furnace problem

[Neal Hannah]

i have a 1996 winn. adventure. the furnace is an sf42 and when i turn the thermostat to heat and turn the fan on, i move the thermostat up to kick on. the fan kicks on for about 30 secs. and them immediately blows the 15 amp fuse. does anyone have an idea what to check ? just bought the motorhome and was in storage. took access panel off to see blower and motor. just looking at it, circuit board and components looked clean. does anyone have any suggestions where to start?

[LVJ58]

Do you have a schematic for the 12v electrical system in your coach that lists the amperage rating for the fuse in the blower fan circuit?

If it calls for a 15amp and it keeps blowing, it appears to be drawing excessive amperage, perhaps caused by an internal short in the field windings or other area in the motor assembly.

Does the furnace ignite before the fuse blows?

[450Donn]

Fan motor shorted out. Take it out and have it tested.

[DAN L]

Originally Posted by Neal Hannah

i have a 1996 winn. adventure. the furnace is an sf42 and when i turn the thermostat to heat and turn the fan on, i move the thermostat up to kick on. the fan kicks on for about 30 secs. and them immediately blows the 15 amp fuse. does anyone have an idea what to check ? just bought the motorhome and was in storage. took access panel off to see blower and motor. just looking at it, circuit board and components looked clean. does anyone have any suggestions where to start?

welcome to the irv2 forum.
maybe these references will help.

Marksrv.com Suburban RV furnace parts

RV Furnace Troubles - Fixing RV Frunace Problems

Service Documents