Nissan Repair: 93 altima motorized seat belts, seat belts, wrecking yard

Question
Both belts quit working at the same time. Replaced the control unit (computer chip and relays in a box under center console) twice (from wrecking yard @$35) with no success. Power in to controller is good, but all outputs to motors are at ground when controllers are connected. Motors work fine when I apply 12V directly to them. Am I just getting more bad computers (maybe they all fail?), or is there something else I should be looking at? NISSAN wants $450 for a new unit.  

Answer
Bob,

Yes, the control units you are getting are pretty much a guessing game.  I would go for it one more time.  Also, before I did that I would be checking the relay to make sure it is not burnt out.  But, I have had a few defective parts at the wrecking yard before and it has taken several times to get one that worked.