Hi,
I just posted this to the Ford Van forum but thought that I'd add it here since the E- and F-series vehicles share a lot of common components:

My 1997 E350 has developed and issue with the power doors. The "unlock", just fine, but the "lock" electronically -- I have to manually lock the doors -- ugh. My van has four locking doors -- FDriver, FPassenger, Side, Rear -- all four locks behave the same way -- don't unlock -- so I'm assuming that all four did not fail at the same time, in the same way.

I've looked through forums, wiring diagrams etc. looking for the power lock "brain" or a master lock that regulates the others but have not come up with anything conclusive...

Any ideas?

Nat