Andy:

You can disconnect the yellow plastic line in the engine compartment and plug the engine side. This will seal the vac system while disabling the door locks. If the tranny shifts better afterwards, you have a leak.

I suspect from your description that you have either a bad rubber connector at the door switch or a bad door switch. Usually a bad diaphram (see below) prevents anything from working.

The locks work by a switch in the driver's door, supplied vac via the yellow line. The switch sends vac down the yellow with a red stripe (I think) line to the other doors, trunk, and filler cap locks. Unlocking the door switches vac to the yellow with green line, and vents the yellow with red, this applies vac to the other side of the lock diaphrams and unlocks them.

Get a MitiVac if you don't have one, and see if you can pump the lock system down. If so, you have either a leak in the vac supply or in the reservior (under the left front fender). A dead check valve (little round plastic thing) in the yellow line by the brake booster will also cause slow or dead locks as the vac bleeds off with the engine off.

You will need the mitivac to check the locks, anyway. You may have a broken line or bad diaphram, causing the others not to work.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!