Front Seats suddenly not working - not FUSE or seat adjustment module (in door)

[M104-AMG]

Driver seat adjustments not working. Cleaned up fuse box connection w/DeOxit and a new 25-amp fuse. Still nothing. Defer to weekend.

Passenger seat adjustment working one day, then next day after reclining passenger seat, now dead/seat not moving. Checked Fuse and replaced. Still nothing.
Took apart passenger seat adjustment module (in door), and "rebuilt" it by using a ScotchBrite and DeOxit. Still nothing.

Is there any jumpers I can do to at least get the passenger seat back-rest returned to its normal driving/riding position ? Or any test points to check for voltage and/or continuity ?

Searched the archives, and didn't find anything.

Ugh!

TIA,
neil

 

[gsxr]

Neil, how about the door jamb switches, and the diode buried in the back of the fuse/relay box?

Is this your 1993, or the TE SuperWagen?

 

[M104-AMG]

Whoops, '88 TE SuperWagen . . .

I thought the diode was only for the insturment cluster. I'll check it. Just seems odd that passenger side worked while driver's side didnt. And then after adjustment the passenger seat, it now doesn't work.

I'll pull the door-jamb switches and squirt with DeOxit as well.

Thanks for the insight.

neil

 

[M104-AMG]

I rebuilt (lots of oxidation) all the door-jamb swtches (6-total), and they all tested good with no measured resistance after the re-build with a ScotchBrite, & DeOxit grease and spray.

Before re-assembly, slightly bend the fingers towards the center spring so it makes positive contact with the circular conduting bushing. I wipe down the conducting metals with DeOxit, as well as a tiny amount of DeOxit grease for both the "fingers" and the conducting bushing. Cabin lights are really bright now.

The "lower" of the two front switches allow +12VDC to flow when the door is open. Unfortunately, both driver & passenger seat adjustments still do not work.

I checked the two 25-amp fuses, for +12VDC, and nothing, even with the car started. Also cleaned-up them up again just in case.
I'll need to check schematic if they are ALWAYS active or only when the seat adjustment is being used.

I'll check the diode later as well.

Ugh!

:-( neil

 

[M104-AMG]

(Note: this is for the 1988 360TE AMG)

Dave- you're correct, the diode is part of the supply circuit to the power seat adjustment.

I'll check both relay K5 (I have bunch of spares), and the diode.

As there was +12-VDC on the lower door jamb switches, yet NO +12-VDC at Fuses E & F, I'm thinking relay. We shall see . . .

TIA,
neil

 

[M104-AMG]

Diode was found with it's enclosure partially unsnapped and NOT fully seated. The diode is position <I> of the fuse box.

Also, the terminal ends of the diode were badly oxidized, same with the pins of relay K5 (power seat relay), which is in position <A> of the fuse box. The diode is position <I> of the fuse box. Rember that, A.I.

ScotchBrite, & DeOxit grease. All is back.

neil

PS: removed oxidition on all the various relays, modules, and DeOxit greased them.