I'm in the process of reviving/simplifying my w140 s280 (m104). I already have a diesel engine waiting to be installed. The car has a non computer controlled tranny.

The car was submerged in muddy water... the interior has been gutted and cleaned. If i were to put it all back together you wouldn't know it was submerged.

At the bare minimum i'd just like to be able to drive the car, have the windows open/close, have all the lights function, and have AC control. That's it.

The thing is, i hooked up a battery a while ago and was hoping to have the windows function via the switches. No dice. The windows work when hooked up directly to the battery though, the motors are fine.

All the ECUs have been removed, I don't know if their absence is causing everything not to function.

Which brings me to one of my options: Gut ALL the wiring and start anew. By this I mean rewiring EVERYTHING. The simpler the better. The w140 has loads of real estate. So a wire and accompanying fuse for each and every component is not out of the question. A separate fuse/relay box for the subsystems look enticing. Makes future repairs and troubleshooting much much simpler. There will be a fuse/relay for EACH window and EACH headlight... something to that effect.
What do you guys think?
I don't necessarily have to use the existing switches at this point. ( I have successfully "hacked" a w124 AC switch panel to work "manually" using a bunch of relays to control the AC and blower. Using the 3 fan buttons originally LOW, AUTO, HIGH... to work as LOW, MEDIUM, HIGH etc etc. Basically redesigning the PCB just to be able to use the stock buttons for that stock look. Did away with the porcupine blower regulator and just used traditional resistors )

OR try and salvage the existing wiring harnesses... on the w140... that's a LOT of harnesses. But that's a lot more tracing work I think... unless someone familiar with the w140's guts can simplify the tracing process. For example, what is this? : I traced the power window switch leads on the center console back to this area... what is that black box?


A bunch of relays can do wonders.

I agree that salvaging the existing wiring may be the better option... but honestly i'm clueless as to how it all works, because of all the junctions and whatever BLACK BOXES the wires have to pass through just to be able to actuate a simple motor that just requires a positive and a negative input...

That's it... lights, windows, ac and the ability to start the motor. The bare minimum. Should be pretty reliable... imagine that, a reliable w140. haha

__________________

85 190E 2.3(SOLD)
86 230E (-->300D) sold
87 300D (-->300TD) sold
68 250S w/ a 615 and manual tranny (RIP)
87 300TD (SOLD)
95 S280 "The KRAKEN" (Turbo 2.9 602 transplant) traded
86 190E 2.3... current project

Ok, I just found out what it does... IT CONTROLS EVERYTHING window related and then some... time to find a replacement... OR just hack it. I opened it up and its messed up quite a bit.

__________________

85 190E 2.3(SOLD)
86 230E (-->300D) sold
87 300D (-->300TD) sold
68 250S w/ a 615 and manual tranny (RIP)
87 300TD (SOLD)
95 S280 "The KRAKEN" (Turbo 2.9 602 transplant) traded
86 190E 2.3... current project

Right now i'm trying to isolate the subsystems...
I know now where the power window switches and motor wires all end up...
I'm still trying to find out where the headlight/markers light/tail light wires go, and where it meets with the switch, pedal.
Once those are identified it's just a matter of designing a relay/fuse box for each system... I hope.

Wiper and hazard systems are next.


The AC is easy enough as it will be a stand alone system much like what I did for my w124.

EVERYTHING else will be removed.

Hopefully, I can somehow use all the stock buttons and controls, even if I have to hack them.

__________________

85 190E 2.3(SOLD)
86 230E (-->300D) sold
87 300D (-->300TD) sold
68 250S w/ a 615 and manual tranny (RIP)
87 300TD (SOLD)
95 S280 "The KRAKEN" (Turbo 2.9 602 transplant) traded
86 190E 2.3... current project