What are the options? I'll be needing: Speedometer, Tachometer, Temperature, Oil Pressure...

What gauges would work with our sending units? The simpler the better... meaning no computers/modules in-line.

It's for a w140. I can get an older cluster from a w124... I can do with just the mechanisms... not really going to use the faces. But if there are more readily available gauges with their own sensors/sending units that would be better.

If you were building a car from scratch... how would you go about the gauges?

__________________

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

Have a look at Auto Meter , Stewart Warner, Datcon Instrument Company (later renamed to Maxima Technologies).

Senders for pressure and temp are a minor part of the system and changing them to match the gauge is easy.

If you want to use Mercedes senders look in a shop manual and see if it shows resistance Vs pressure ( or temp ) they get a gauge to match.

A tach is semi universal needing the negative side of a ignition coil. A coil on plug system might need a converter but given these are so common these days I'd expect some tachs to have this built in.

A speedo can be more difficult if cable driven as not only do you have to match the cable type, you must match turns per mile. A more direct route would be an electronic speedo reading from magnets on the drive shaft , tapping into a abs sensor or even the trans output shaft speed sensor.

Thanks!
I converted my w140 gasser to a diesel... so my tach gets its signal from the flywheel... I wonder what kind of signal it puts out.
An electronic speedo is my only option then... as the w140 didn't come with a cable driven speedo.
Good to know that the temp and pressure sensors should be easy.
Thanks. Will do further research with the companies you mentioned.

__________________

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

If building a car from scratch, I'd integrate a tablet and do something like this Introducing Shadow Dash MS | tunerstudio.com

__________________

90 300TE 4-M
Turbo 103, T3/T04E 50 trim
T04B cover .60 AR
Stage 3 turbine .63 AR
A2W I/C, 40 LB/HR
MS2E, 60-2 Direct Coil Control
3" Exh, AEM W/B O2
Underdrive Alt. and P/S Pulleys,
Vented Rear Discs, .034 Booster.
3.07 diffs 1st Gear Start

90 300CE 104.980
Milled & ported head, 10.3:1 compression
197° intake cam w/20° advancer
Tuned CIS ECU
4° ignition advance
PCS TCM2000, built 722.6
600W networked suction fan
Sportline sway bars
V8 rear subframe, Quaife ATB 3.06 diff

I'm allergic to anything.... hi-tech. hehe

What are the specs that I should take note of re: signals, voltages, resistance and such?

__________________

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

If you want to keep it simple electrically, simply use mechanical temperature and oil pressure gauges. They are available from any of the aftermarket guage mfg's.

__________________
2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

Annoy a Liberal, Read the Constitution

What is wrong with a MB cluster
The 140 at least gassers gets its speedo info from the ABS sensor ring on the front wheel. It is processed thru the ABS computer into a elecrical signal 9pulsating DC whic is coverted to a sine wave. The oil pressure and level are processed via a matrix and fed to the dash.
All 140 had two coils and the later had a coil for each cylinder.
The early to mid 123 had a mechanical oil pressure guage, and the tach was driven off the alternator. The fuel guage is a normal affair where you just have to match the resistance between the sender.

In MBs released earlier than the W140, Diesel tachs are different from gasser tachs. There's either a tach amplifier that reads off a crank damper trigger or EDS reads off a ring gear trigger/s. I don't know how to modify the ring gear signal to drive the S280 tach. IIRC 60x tachs are glorified voltmeters rather than pulse counters if that helps. How did mach4 deal with it?

Did your 602 come with a ring gear sensor? Is there a bung below the starter cutout in the transmission flange? Maybe you can retrofit a 61x crank damper lug and tach amp.

Hopefully the S280 has analog gauges wired directly to the senders. Some cars from the 90s on have gauges driven by an ECU or BCM. Surely you've seen cars in which the gauges can display a self test. Our '97 Caravan has such gauges along with pushrods. Go figure.

Sixto
87 300D

Yes, there is a sensor in the ring gear similar to my 87 s124... I think retrofitting an older tach system is the way to go... what components should I get? IIRC my old 87 euro 300D tach passed through the OVP, Klima and finally the sensor.

The s280 doesn't seem to have analogue gauges. There's a very complicated looking PCB behind the dials... the dials themselves can just be pulled off, they have long pin connectors... most have 3 pins, but I think the center pins are just mounting pins (ground?) Trying to find out if those pins can receive a signal form analogue sending units...(i doubt that)... if not, retrofitting analogue gauges from a 124 seems doable... while still using the 140 gauge faces and thus the lighting.

So my mission now is to find out the paths of each of the gauges. ( Temp, Oil pressure, Tach, Fuel... and speedo (though there's no way of that being analogue/cable driven)
There's lots of space everywhere so it'll all be "invisible".

All info is welcome.
Sensor--->?????--->Gauge

__________________

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