Window has to be down.
Try using a small 12v battery to bring the motor down, i've actually had to use my 7.2v R/C car battery once and it worked fine....
It might not be the motor, it could be something else, check www.4crawler.com he has lots of good troubleshooting tips.

89 4Runner
3" BL, M/T locks, 33"bfg mt, bilstein, Kayline, tubebumper, toyotafiberglass panels
TBI: Elocker,3.4 w/ORS,b+b,S2Sstg2cams,arias pistons,P+P intake,TRDs/c,URDpullies+7th,downey headers,MAPECU2,WEGO WB, SupraMAF,walboro255,stg4clutch, EPaOo2 sim