My 3 amp fuse keeps blowing in my furnace. Sometimes the fuse lasts a couple of hours and sometimes it lasts a couple of days. I've checked the wiring in my thermostats and they all seem to be connected fine. Last time I replaced the fuse I blew in the fuse contact and wiped off the fuse hoping the connection was just dusty. If the fuse blows again, what steps should I take to trouble shoot the problem? Thanks.

Try a higher amp fuse.(the next one up)

My 3 amp fuse keeps blowing in my furnace. Sometimes the fuse lasts a couple of hours and sometimes it lasts a couple of days. I've checked the wiring in my thermostats and they all seem to be connected fine. Last time I replaced the fuse I blew in the fuse contact and wiped off the fuse hoping the connection was just dusty. If the fuse blows again, what steps should I take to trouble shoot the problem? Thanks.

There is a reason the factory installed/reguires a 3 amp fuse. Find the short, repair but I would advise to not use a larger amp fuse,you might end up replacing more parts than need be by trying to cut corners