On and off heater/air blower

[cuning]

my 1990 420sel blower stopped blowing, replaced fuses, cleaned connections kicked the underside where its located and it came on a few times, but did not come on again by its self after turning off car. I turned my self into a pretzel to get it out, checked for baring play, no play, spins nice, cleaned it all out, attached 12 V battery, worked excellent, after installation worked great, then one day nothing, after a few miles, it comes on by it self works fine, next day nothing, is their something ell's I can check? im thinking a bad ground?

Also my dash lights at night come on then go off for no reason, then come back on when they want too just like the blower?. do you think this problem is connected?

I have had this car for 9 years, its never let me down, also I notice after I unlock the drivers side door, after driving down the road for 10 min i hear the other three door locks unlock themselves? Ideas anyone?