I have an older dishwasher also and recently mywife also complained about it not cleaning right... so me being the man I amtried in vain to clean the things... Bought new spray arms online and installedthem in minutes...now the thing works like new... However I have also foundthat if the heating element goes bad then that also can mess things up bad...So I would buy new spray arms, and also check out the heating element to makesure it is working... Here is a tip that will help you with the onlinebuying...
Dishwasher SprayArms not Spinning
How to Buy ApplianceParts Online
A bad heating element causes many problems in dishwashers...
Dishwasher Problems The HeatingElement not WorkingDishwasherMaintenance
DishwasherResidue and Film on Dishes
Asker's Testimonial "explanation very clear. will give it a go and see howsimple it was. thanks Ronnie " - ronnieshomes
my spray arms won't spin either,