Atwood furnace not working, random problem with the fan blower

[Jill]

I've read through all the furnace threads and haven't seen a problem quite like ours so starting a new thread.

We are on the coldest trip we've ever been on and are having random problems with our 7 year old Atwood furnace. Occasionally we get lucky and it turns on and runs for a while. Most of the time it doesn't work at all. We are running on shore power. I tried disconnecting and have the same issues when running off the battery.

We turn on the thermostat and hear a click. A few seconds later the furnace clicks. Then nothing happens at all. The blower does not come on. We get the 'Airflow/Limit switch' indicator. I'm thinking that's because there is no air flow at all due to the blower not coming on. I used our high pressure air duster on it in various places and sometimes that helped it start, other times not.

On those rare occasions where it works, sometimes you can hear the fan changing velocity, and most times the furnace suddenly shuts down before reaching the desired temperature.

From reading the other threads I'm thinking it could be an electrical issue, insufficient power to start the blower and keep it running? All other electrical components are running fine. We’ve looked for loose wires and nothing was obvious. Or it could be we just need a new fan motor. We haven’t removed the housing and looked inside though as it appears to be a big job. We have a multimeter with us and will check to see the power coming in if we can figure out where to check it.

Either way we’ve decided to continue our trip (4 more weeks) best as we can with portable heaters and have a tech look at it when we get home. I posted this here though in case anyone thinks there is anything else we can try. Thank you in advance!