Help, Why no tach in SC with MSD?

[}{arlequin]

yes, I've done the search(es).... still no clear answer


The MSD is hooked up to an '83 SC. Big red is pwr, big black is ground. Another red from MSD is hooked up to switched power.

Additional, "plug-in" green and purple wire harness (supplied by MSD) is connected to each of strands in the green coaxial coming out of the distributor.

Orange and black are hooked up to the coil, pos. and neg., respecitvely.

White wire out of the MSD is not used.

Car runs fine w/ this setup.

Now for the tach:
a) Is it possible to skip over the "tach adapter" and wire up the tach witout it, just like in earlier cars? (Meaning, can I hook up the tach wire into the distributor/MSD signal splice?)

b) Is the tach wire in an '83 SC *still* the black wire w/ purple stripe in the 16-pin connector? (I remember reading a while back that some cars varied, but it was MOSTLY the black/purple)

c) If the tach adapter has to be used, which wire goes where?

thank you.

[Rick Lee]

Bump.

This is my car. A big warm Pasbt thanks to Charlie and Dave for putting up with me.

[jdowty3]

I just did this install a few days ago. Run a wire from the Tach Output (male spade connector on the same end of the SMD unit as the Mag Pickup green & violet wires) to the TD connection on the CDI plug (black wire opposite the red). FYI - you can create a kill switch by running the MSD white wire to ground via na alarm or manual switch.

[Lukesportsman]

I always thought that this kind of kill switch was best bang
for $$. The engine will crank, fuel will flow, but she just will not start. Wastes time and can still be hard to bypass....and we know time is the thefts worst enemy.

[VaSteve]

Rick
If you want to come over and look at mine I would be glad to show you how to hook it up. Or maybe I could get a pass and swing by tonight.

You don't need the tach adaptor.

There is a good thread showing what to plug in where on the 6 pin connector. I will search and edit if I find it.

Steve


Edit: Found it. Assuming you didn't chop off the plug, this the way to do it:

MSD Ignition Install

[mb911]

The tach signal wire is on the other side of t6he wiring harness. My sc engine in my 77 body works perfect together but with a nwer tach I think you need the adapter. You should not use the splice wire idea you thought about this will cause major problems

[Par911]

RL, get Steve's help. He did a nice MSD install and already went through the headache of setting it up, plus he's got an '83.

[}{arlequin]

Originally posted by jdowty3
Run a wire from the Tach Output (male spade connector on the same end of the SMD unit as the Mag Pickup green & violet wires) to the TD connection on the CDI plug (black wire opposite the red)

what's a "TD connection"?

Btw, thanks for the help, it's helping us narrow it down.

[Early_S_Man]

Dave,

The 'TD' connection is the Tach Drive designation at the CDI unit ... but, in the context here it means the Black/Violet wire at the 6-pin CDI connector on the way up front to tach and rev limiter relay:

[jdowty3]

It is Terminal D on the 6-pin plug. If you look at the side of the Bosch CDI, it has a diagram of the plug abd each connection is reference by a letter or number.
Large red is 12v power and large black is chassis ground.
Brown wire to coil neg is 31-1 and connects to MSD thin black wire
White wire to coil pos. is A and connects to MSD orange wire
Red switched power wire is 15 and connects to MSD thin red
Green wire from distributor is 7 and connects to MSD magnetic pick-up green wire
Shield wire around distributor green wire is 31D and connects to MSD voilet wire
All that leaves is a black wire (with violet stripe?) that connects to the MSD Tach output connector and the MSD white wire.
If you have points, you use the white wire and leave the magnetic pick-up wires disconnected.

[}{arlequin]

Warren,
Thank you for the excellent diagram/help as always.

Jim,
That's perfect. Makes things much more clear.

[jdowty3]

No problem Dave. Like I said, I just did this install on my 83 on Wednesday afternoon.
Did you get a different coil or are you using the Bosch coil? I went with a MSD Blaster SS. I haven't notice a Butt-Dyno power increase but the idle is smoother and I hope to get better MPG. I still need to regap my plugs as previous threads have suggested.

[Rick Lee]

I got the Blaster coil on there.