I was under the understanding that on the 124 chassis, the door, trunk and fuel door vacuum system was operated by the vacuum pump under the rear seat. If so, I could rule out the locking system as the culprit.

I thought that the climate control and engine vacuum was getting its vacuum from the main pump on the front of the engine (which I upgraded to the latest version in July, 2007).

Anyone know?

Thanks,
The Tenor Man

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Currently Driving.....
1987 Mercedes Benz 300D Turbo - Daily Driver.
2004 Buick Rendezvous...Smaller than it looks!
2005 Mitsubishi Galant - Not bad for a tin box...Lousey Seats
Past Vehicles.....
1994 Dodge B-250 Van- GAS HOG..Succumbed to rust!
1989 Mercedes Benz 260E - Totaled but no one injured.
1977 Mercedes Benz 240D - Loved it, but SLOWWW! - Succumbed to RUST!
1976 Mercedes Benz 240D - Same as above! -
1975 Mercedes Benz 240D - Same as above!