Central Vacuum Locking System - W140

[sail42]

My '92 300SD (W140) appears to have a problem with the central locking system. The fuse box in the trunk, circuit 11 has a blown 20 A fuse. I replaced it and it immediately blew again. This circuit is for the central locking system and misc lighting.

Is it possible that a short circuit is now causing the fuse to blow or is it more likely that the central locking system pump is locked and over amping the circuit.?

Before I buy a new pump (if needed) and I dissect the car in search of the culprit, I thought I would ask the experience of the forum. If inspection is required of the pump, which I believe is located under the back rear seat, I could use some advice on the rear seat removal as this seat is fastened to the body in a different manner then the usual two clips located at the base of the seat.

A checkout procedure etc. would be greatly appreciated.

Thanks,

Sail42

1992 300SD/500SD - 95K
1994 S350 - 92K

Previously owned
1987 300D - 225K
1985 300D - 387K
1979 450SEL 225K

[Silver Boat]

I would just disconnect the pump and replace the fuse and see if it blows again. That will tell you if the pump is over amping the circuit. I would take the pump apart as much as you can to see if it is something simple. Could be fun/educational as well. I was one of the kids that took all his toys apart!