seat problem 300SD

[rsmartin]

Driving from Maryland to Tennessee in 85 300SD. Got tired about 2 am and stopped to take a nap. Lowered seat back for a nice rest. Woke up ready to go. Seat back would not raise!! Head rest would not move up and down and front of seat cushion would not move. Just fore and aft and rear of seat up and down. Took switch apart, cleaned contacts etc. put all the ball bearings back after many attempts at 3 am and no difference. So I had to drive the last five hours with my no seat back to rest on!! Now I'm home and looking into situation. I can hear a clicking under the seat when I try to move headrest, seatback and front seat up and down. What would happen all of a sudden to cause this. Seat worked perfectly previous to my nap.


Randy
84 300SD
85 300SD

[JPutt]

Because of the clicking it sounds mechanical but also check the fuses. My 300SDL has more than 1 fuse that controls different functions between the seats and I found one blown one afternoon when the passenger seat wouldn't adjust but the drivers would except for the headrest????...Just a thought..Good Luck..John

[rsmartin]

blown fuse in the fuse box in the engine compartment. hmmm... i looked at the list of fuses in the lid and saw one that said seat adjustment (fuse 5) and thought well seat moves forward and backward and rear of cushion up and down so wouldn't be blown fuse.. BUT i looked again this morning and sure enough it was blown, replaced and everything works again slick as whistle. very interesting that only certain seat adjustment functions are on the one fuse.

thanks for the tip... i should learn to alway thoroughly check fuses.

this happened once before when my instrument cluster went totally dead... i looked at the fuse and it didn't appear to be blown... so i kept diddling around until i decided to check again. this time i took it out and when i did the little tip of the aluminum end of the fuse came off.... so the fuse in the socket didn't look blown but the contact end was broken where u couldn't see.

happy days, i can drive back to Maryland in comfort once again.

thanks John

PS. I just joined MBCA last week even though my name says i'm a visitor

[marlinspike]

Yeah, something Benz did was if you look there are a lot of half redundancies in the fuse box. I guess the reasoning in this instance is in case you have no spare fuses, and the fuse that deals with the seat back blows, you can borrow the fuse that does the rest of the seat (just like if the instrument cluster goes you can borrow the one of the ones that deals with the radio).
An FYI on the fuses...the go kinda often because some dunderhead decided to put aluminum fuses in a fusebox with brass/copper contacts. www.mercedessource.com sells brass/copper fuses. The don't corrode as quickly so they last longer.