2000 Accord EX V6 sedan heater fan stops running for no obvious reason, and if I leave the control panel on the same settings it will start blowing again. It starts again sometimes in 30 or 40 minutes and sometimes the next day. AC compressor does not run when I start it from the control panel.

So I replaced 2 7.5 amp fuses, the 40 amp heater fan fuse and the heater fan relay, then everything was working as expected for about 24 hours. Then everything stopped working again for awhile, then restarted for about an hour, then quit again.

Can a grounding problem suddenly crop up like that?
Thx