Tach hookup!

[Turk]

I need help hooking up my tach with the factory wiring from Shelby for my CSX4000.

I don't want to experiment.Iif you have a CSX 4000, an MSD 6AL with a MSD distributor and you are using Shelby signature Autometer tach, you could easily answer my questions, and I would be eternally grateful.

I blew up one MSD box yesterday, I would like to make the new one last a little longer.

TURK

[Specialk]

Turk,

I will gather some info and get back with you.

[Double Venom]

Turk! Hey fella, I've been sitting back, quietly awaiting your new little piece of heaven to be finished!

Your system is exactly what I plan on hooking up for Jenny's car. I've never had a problem with that installation, but now you are making me nervous. (So what else is new )

Can you tell me what happened when you hooked up the first MSD box? Also, when you do figure out what happened, or the correct way to plug in these components would you pass it along?

DV...DVSF III is going to be a site to behold!

[Ron61]

Turk,

Have you got that baby up and running now ? I am looking forward to better weather soon and a trip down there to drool over it.

Ron

[Turk]

DV,
One way to preserve your MSD box is NOT to put the (+) orange wire and the (-) black wire on opposite terminals of the coil. If you do, not much happens until you hook up two more wires for the tach that is on the wiring harness that are meant for the non MSD applications.
Even then, if you hook those up wrong following the earlier color scheme of Orange being (+)....still nothing happens.
Car doesn't start but no damage takes place.

UNTIL.....you realize your mistake(s) and decide to correct only hjalf of your mistakes, by reversing the leads from tach, thus applying 12 V from the ballast resistor directly to the coil!

That is when the hell breaks loose.
Three coils and 2 MSD 6 ALs later I am now an expert!!

TURK

[Turk]

Ron,

If you want to see the "baby" running try coming down here by February 2005. If you just want to see it and say hello to me, anytime will do.

TURK

[HighPlainsDrifter]

Turk,
The MSD box puts out lots of amps from the big capacitor in it, and goes directly to the coil. I would check the size of the factory wire or suggest not using it and running the 2 MSD coil wires directly to the coil. NO other wires should be attatched to the coil. The tach lead is picked up at the msd box. Also if you run the white wire (from the msd box) through a hidden toggle switch to ground, you have a 'kill' switch and nobody can start your cobra but you.
Good luck,
Perry.

[Turk]

Perry,
Thanks. That is exactly what I did with the WHITE wire on my earlier car.It worked as a kill switch, and it was well hidden.

Re-reading the MSD manual, I am lead to believe there should be just the two wires from the box coming to the coil. SImple enough.
This time around I was careful enough to install the wires to the correct terminals. It worked !

Now I have to get the tach working, and I am all set. I just need to find out from someone with a similar setup as mine and see how they hooked their tach. There are two wires in the back of the tach, only one wire coming out of the MSD box.

TURK

[PatBuckley]

Turk -

What does it say on the back of your tach?

Ground, + 12V, and ignition are some choices....

Pat

[petek]

Turk,

(from the installation manual on the MSD site)
TACHOMETERS
The MSD Ignition features a Tach Output Terminal on the side of the unit. This terminal provides a trigger signal for tachometers, a shift light or other add-on rpm activated devices. The Tach Output Terminal produces a 12 volt square wave signal with a 20% duty cycle.

(later in the manual)
No "Tach Adapter" is required for Autometer gauges.

(from the Autometer web site)
It looks like you'd just take the green wire from the tachometer and connect the wire to the tachometer output on the MSD box. I assume the other wire on the tach is black, the black wire would go to ground.

[Ron61]

Turk,

I use a Jacobs Pro Street and I have it the way Petek just posted. I know the Jacobs and MSD are somewhat different but my green wire from the Jacobs unit goes to the tach. I have VDO gauges in one car and an Autometer tach in the other. Both are wired the same way.

Ron

[Turk]

It seems, when MSD says they don't want anything else connected to the coil other than the orange and black wires that come out of their 6AL, they mean it.

I have to connect the tach some other way. I did get a very responsive phone call from Shelby American today telling me the steps to omit, and how to hook the tach as well as how to by bypass the ballast resistor.

I'll go home tonight and see what else I can burn

TURK
Thanks guys for the help.

PAt, I will let you know what is in the back of the tach when I get back home.

[computerworks]

E=IR

[Jamo]

Ron

Scarey thinking about it, hey?

[Specialk]

Rons,

Leave Turk alone. I think he is about to loose his mind!

[Jamo]

Rather presumptuous of you...