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Help with Instrument Cluster / Tacho

Started by SELfor50, 17 September 2007, 05:43 PM

SELfor50

Peeps, i need some assistance with the upgrade of Instrument Cluster V1.0, to IC V1.16 - Revision Tacho.  ;D

After ripping out the IC and pulling it apart, i have a few questions.  Mainly stemming around how i'll connect the tacho considering it wasn't there before and also what a few certain items are behind the IC.

I was also completely gutted to find out the the speedo seems to have been swapped at some point and is from a 350.  Hence the lower km's and different shift marks.  The metal on the back of it is also different colour to the metal behind the clock that was where the tacho is now.

SELfor50

Should really attach the pics:

The Workbench


The 2 Speedos - Notice the shift mark difference:


 

Where the workbench should be:


Absolutely Gutted, guess the KM's arent' real?!


1.  What's 1 for? (see continued pictures)


2.  More help needed with this:


3.  Also, what's this - is this the cruise control unit, or another computer?


4.  Installed, without Tacho working and main dash lights not coming on - everything else is working.
Any suggestions on why the main IC lights aren't coming on anymore? ???



oscar

Cam, I've got to do a tacho install on the 280s, I was hoping you were posting how to do it. :D

But it has been done before.  Here's an old thread on how to do it though it's annoying that most of the pics are missing.  Though they were in the gallery hopefully they still are.  The pics showed exactly what to put where.
http://forum.w116.org/mechanicals/installing-tachometer/0/

This next thread has got some pics of my 350 cluster down the page if you want to compare the connections.
http://forum.w116.org/mechanicals/faulty-tachometer/0/

My 350 speedo doesn't have that plug connection like yours does ??? I have no idea what that does.  It may have to do with CC as perhaps the parts numbered 1,2 and 3 but I've no idea.
1973 350SE, my first & fave

oscar

Aha!  Chad's pics.  May they never be lost again.  Refer to these pics with 116.025's posts.



1973 350SE, my first & fave

SELfor50

Hahaha.... you beat me to it mate.

I just found them too and was bout to post when i refreshed and saw them.

"The force is strong with this one"  ;)

So just for confirmation, i connect to the ignition coil on the right hand side?  so undo the little screw and connect a wire to there and run it round the engine bay.

Any suggestions for the best way to do this?  And i'm guessing i need some sort of insulated / shielded wire for this??
As for running it through the fire wall - where the vacuum lines go through is ok right?


oscar

 :D

BTW, NOT the igniton coil.  Like Pat said, it kinda connects with the ignition module.  I'm scratching my head thinking why don't I just go out and check - so I did.

The signal wire is attached to the wiring block behind the coil where the first yellow arrow is then follows the wiring back to the engine bay.  The green/yellow wire at the same block goes to the ingition module. 




It follows this path then enters the firewall thru this grommet on the LHS of the vehicle

Then I don't know what happens.  Here's a pic of the plug.  The wiring diassappears into the dash.  I tried to reach in and feel where it goes but couldn't.  had a look in the fuse box and I'm still not sure where the red wire goes.

1973 350SE, my first & fave

SELfor50

Thanks Oscar, you're a champion!!!  I'll give it a crack when i get home tonight..

Any suggestion on why the IC main lights are not working?  I thought the contacts might need to be jiggled, but that didn't work.
Might swap them from the old one and see if they come up..

Once again, you're true blue!  ;)

oscar

Mate, anything for a pit pass :D

Re the IC lights, I reckon it's probalby a loose bulb or dodgy earth.  I'm not a 100% but I think the illumination is from the two bulbs connected to those very long bulb holders either side of the speedo at the top. 

The earth comes from the round multipin connector of which one of yours has more pins than the other.  I don't know if that's an issue.  Use the same tripple combo guage as you had on before when the lights did work if you think it is.

Here's a couple of spots you may have earthing issues with.   For me the earth was bad where the copper shim was.  The tripple combo gauge picks up earth from the multipin, then the speedo's housing seemed to conduct earth via contacting that copper shim/washer where I put more solder on.  The clock/tacho then picks up the earth by it's housing contacting the speedo's housing.  If the screws attaching the three guage housings are loose, you're gonna get a bad earth. I ran a bypas wire by soldering to that shim/washer directly to the clock/tacho housing.  It fixed my jumpy tacho.

With the light's however, I think the first one as in that picture may get the earth from contact with the metal strip in the PCB.  The other bulb maybe from the clock/tacho housing.  Again, not really sure, but give 'em both a bit of a twist and check the globes and see how you go. Tighten the screws that attach the three guages together first.

And lets not forget your other questions. I'm a s curious as hell to know what the other bits are in your first post. Anyone?
1973 350SE, my first & fave

13B

Which car is getting the tacho?  The silver racer?  Was it donated from ol'smokey?  Why not just put the whole intrument cluster in?

Hard to believe silver racer had a clock not a tacho considering its supposed to be a '79... still i guess a tacho in a race car would be pretty handy.

Do M117 motor have a rev limiter?
450SEL 6.9 #5440 = V MB 690 , 450SE # 43094 = 02010 H , 190E/turbo # 31548 = AOH 68K

SELfor50

Quote from: 13B on 17 September 2007, 10:56 PM
Which car is getting the tacho?  The silver racer?  Was it donated from ol'smokey?  Why not just put the whole intrument cluster in?

Hard to believe silver racer had a clock not a tacho considering its supposed to be a '79... still i guess a tacho in a race car would be pretty handy.

Do M117 motor have a rev limiter?


Silver's getting the Tacho - I actually swapped over the entire instrument cluster except the housing, cause the housing from Ol' smokey is in shyte condition!
Both Silver and Ol' smokey are meant to be '78>?!

The rev limiter is basically just the rotor in the dizzy cap right??   Whether it's got the spring or not?  I'm gonna look at that tonight anyway, after connecting the tacho.

Oscar,
Thanks again mate, i'll check out the contacts as per picture tonight and give them a little brush as well.
I'm still keen to know what those other things are too?!

SELfor50

Quote from: Patrick Bateman on 17 September 2007, 06:06 PM
Sorry to hear about the speedo being replaced. Its possible that it was replaced due to the odometer not working anyway, unless you suspect something underhanded to of gone on. Whats the over all condition of the car like?? from my experience you can have cars with 350,000ks in better condition than ones with 150000ks, so it all depends on how well its been looked after.

PB, all good mate - i have the service history for the past 10 years and the km's are totally consistent with the receipts. (for the 150,000 that is)
The paint is absolute shyte - though i do know for sure (from a mate in bungendore) that the bloke who owned it did just have it sitting at his property for bout 2 years doing nothing.  Also MB Spares said that the engine appears to be in good nic, cam's/lobes/rocker arms etc all seem pretty tight.
Either way, the engine goes pretty bloody good.   8)

Pics of instrument cluster installed and working.  :)








Is anyone able to provide some info regarding these other components inside the dash from my first post?? 

Godfather?  ???

Ryan1980

hey guys thanks heaps , i owe someone a beer! I just replaced my clock with a tacho from a donor car, was made a lot easier thanks to this thread :) I too had trouble with the IC lights, turned out power wasnt getting to the green wire! But all fixed now.

oscar

Good stuff Ryan.  It pisses me off to no end when I play with my 280S and go to look at the tacho and see the big ol' clock instead.  If you guys can swap one in, I'm sure I can too.  ;) One day ;D

Cam, re those unidentified parts,  maybe you should start another thread titled " WTF are these" ::) ;D  I'm skip reading a lot of threads and missing some altogether these days only coz it's hard to catch up with all the reading.  I can only imagine others that know the answers are doing the same.  Everyone will at least look at a "What's this part?" kinda thread.
1973 350SE, my first & fave

Martin 280s

Bit of a daft question...but, would the tacho from a 350 work the same on a 280  ???

oscar

Nup.  I should say it will work but will read incorrectly, ie less than it should.  A 450's tach will read correctly in a 350 and vice versa except the redlines will be incorrect (not that it matters much).  But a 280 needs a tacho that will count every 6th pulse not every 8th.
1973 350SE, my first & fave