My mother's Coleman 7680C856 furnace (mobile home), will not come on. The first thing I checked was the pilot lite which was on. I've also checked the breaker box, the gas to the furnace, turned the furnace off for a few minutes then on. If I turn the fan "ON" via the thermostat, nothing happens. I've replaced the thermostat and all the wires looked fine, but still nothing.

While searching troubleshooting sites, I found one that suggests these symptoms could be either the blower motor, a loose connection (not sure where) or fuses. But I can not find anything about fuses on any of these sites. I will go back to her house tomorrow and see if there are any loose, broken or old/damaged wires but other than that, I'll have to start replacing parts until I get the right one. Help.

Thanks.

Do you have a multi meter? If so, check to see that there is voltage coming in to the unit(just follow the incoming power into the unit and check for 120v. If 120v present, check for 24v to gas valve when unit should be firing. Please let me know what you find.