I've been relentlessly pimping this solution for some time...

My '89 Vanagon was factory equipped with PDL, but the actuators decided to
randomly die, causing the problems in the OP.  For the price of a little
more than one VW actuator, I was able to swap in a complete set of
four Swiss-made
MES actuators<http://www.a1electric.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=AEOS&Product_Code=W02F-712T>(using
the stock mounts) and added the remote feature. I fished in new
supplied wiring for the front doors (thus bypassing the sketchy problems
with chafing inside the bellows), but tapped into the stock wiring for the
slider and rear hatch. I'm very pleased with the results.  Highly
recommended

--
Casey