w111.026 Wiring Diagram - PeachParts Mercedes-Benz Forum

justininia · #1 06-21-2013, 11:49 AM

Good day, everyone.

I am on the hunt for a 1969-70 280SE Cabriolet 3.5L wiring diagram (w111.026 chassis) for a 280SL V8 project. The SE has an electrical tachometer instead of cable driven.

I've been scouring the web looking for an owner's manual but haven't had any luck. It also doesn't appear to be in our collection of service manual CDs, either, and I don't think it is worth the $100+ to add it just for a wiring diagram. Hopefully someone happens to have a scanned copy of the insert with the legend. I am certainly willing to buy an owner's manual if someone has one for sale.

Thanks,
Justin

Tony H · #2 06-21-2013, 02:53 PM

I have scanned mine at High Resolution and can send to you if you PM me with your email.

justininia · #3 06-25-2013, 12:39 PM

Good day.

Thanks for e-mailing the wiring diagram.

As I am looking over the tachometer wiring, I see something called Adapter (Tachometer). The Adapter goes between the tachometer and the coil side of the 6 Ohm resistor. EPC isn't turning up any results. I am hoping that someone has disassembled one of the 280SE/C's far enough to know what that part might be.

Thanks,
Justin

Patrol2620 · #4 03-16-2014, 04:18 PM

Quote:

Originally Posted by Tony H

I have scanned mine at High Resolution and can send to you if you PM me with your email.

Hi Tony can I have the same diagram please, I have some fried wires under the dash still works but needs replacement for sure, thanks for your help.

mercmad6.3 · #5 03-19-2014, 08:25 PM

The tach uses the distributor side of the coil for it's signal ( - or negative) . The signal goes through the tach and to a Brown lead with a ring terminal which is connected to a bolt just inside the dash,to the right (I think from memory) of the tach.

Patrol2620 · #6 03-20-2014, 12:44 PM

Quote:

Originally Posted by mercmad6.3

The tach uses the distributor side of the coil for it's signal ( - or negative) . The signal goes through the tach and to a Brown lead with a ring terminal which is connected to a bolt just inside the dash,to the right (I think from memory) of the tach.

It is most likely that the bolted wire is a ground wire for the lights in the tach, there are basicly four wires to the tach although it is a 6 pin connector. Getting the wiring diagram is best, on the other hand it would be good enough to know which pin is for the tach signal or the wire color.
I tried contacting Tony he seems to be very helpful person still waiting.
Justininia please forward me the diagram if you can please
Thanks

Patrol2620 · #7 03-20-2014, 12:47 PM

I am about to disassemble my tach to see what is inside and will post photos

Patrol2620 · #8 03-20-2014, 01:00 PM

Ok the tach is dismantled. It looks Chinese to me hope it helps.

Ops I dont know how to upload the photos I ll retry after I check that

rashpulikkal · #9 03-20-2014, 01:01 PM

I have a problem with E320 1994 coupe as high idle after restart the car.

rashpulikkal · #10 03-20-2014, 01:01 PM

anybody can help me for solve the issue.

rashpulikkal · #11 03-20-2014, 01:03 PM

First start normal idle but after stop and restart the car getting idle around 1300 RPM, then stop engine and keep 30 minutes the car normal idle again ,

mercmad6.3 · #12 03-20-2014, 05:34 PM

Quote:

Originally Posted by Patrol2620

It is most likely that the bolted wire is a ground wire for the lights in the tach, there are basicly four wires to the tach although it is a 6 pin connector. Getting the wiring diagram is best, on the other hand it would be good enough to know which pin is for the tach signal or the wire color.
I tried contacting Tony he seems to be very helpful person still waiting.
Justininia please forward me the diagram if you can please
Thanks

There is a brown wire for the lights,it's also connected to the speedo. As long as your loom is basically all there ,there should be a large group of brown wires to the ground connection bolt.
Dash light power is grey with a red tracer ,ignition signal feed is black or black with tracer. The pins should be numbered and these numbers relate to the DIN codes used on ALL german cars.
DIN 72552 - Wikipedia, the free encyclopedia
http://www.e38.org/understanding%20euro%20wiring%20diagrams.pdf
So once you know which color wires you need to find,and the pin numbers on the rear of the tacho are known,it's dead easy to sort out.

Patrol2620 · #13 03-21-2014, 04:03 PM

Thanks mercmad6.3 the info you provided is very helpful.
Out of the four pins three are nessesary for the tach to function one is ground, one is marked 1 so that must be for the usual ign input, now the third one is interesting it is marked 15/54 so I would assume it is the tach signal input, if that comes directly from the coil -ve side then the signal should be a 12v on/off pulsation 4 times per one engine turn (8 cly). Is that true?

mercmad6.3 · #14 03-21-2014, 05:12 PM

Thats it. The signal speed varies according to how many pulses are fed, a result of the points opening and closing. The tach is basically an electric motor which only turns through an arc, not a full rotation. It works against a spring which in turn, forces it back as the number of pulses reduces , resulting from the dropping of the power fed to the 'motor'

Marrs · #15 03-21-2014, 09:37 PM

Quote:

Originally Posted by rashpulikkal

I have a problem with E320 1994 coupe as high idle after restart the car.

Hello friend, it is traditional here to start a new thread with your problems so we do not get confused when dealing with each individual issue. Please post a new thread with a clear title explaining your issue and you will surely get quick help. I will also send you a PM with other info.