Msd ready to run and centech

[KBUCK1]

Ive got a msd ready to run distributor and a new centech harness. Nothing is currently wired as far as alternator, battery, starter. Im looking for the simplest (cleanest) way to do this. Ive got the explorer serpentine so Im running the 130 amp alternator. I understand how to wire it I believe. It looks as though if I use the gear reduction starter that I will not need the standard starter solenoid switch thats commonly used. Does any one have any experience with wiring the ready to run msd distributors?

 

[blubuckaroo]

Can anyone explain what about these distributors is "ready to run"? They'll still need to have the advance curve set properly for the particular motor. I think it's a marketing thing.%)

 

[badmuttstang]

Ready to run means no ignition box needed

 

[blubuckaroo]

Ready to run means no ignition box needed

Well then it should be called "mostly ready."

 

[badmuttstang]

Agreed but it is msd which means put back in the box and run away to most on here. I have never had a problem with msd and do agree distributors of any brand will run on any motor but to get the most out of them they need to be set up but that's not what he's asking. Which is wiring it up cleanly with a centech harness.

 

[blubuckaroo]

Ive got a msd ready to run distributor and a new centech harness. Nothing is currently wired as far as alternator, battery, starter. Im looking for the simplest (cleanest) way to do this. Ive got the explorer serpentine so Im running the 130 amp alternator. I understand how to wire it I believe. It looks as though if I use the gear reduction starter that I will not need the standard starter solenoid switch thats commonly used. Does any one have any experience with wiring the ready to run msd distributors?

Even though the original starter solenoid is bypassed for the starter, the solenoid is still in the ignition circuit so the coil gets a full 12 volts during cranking. You'll need to find out if your new distributor needs a full 12V.

 

[badmuttstang]

that dist. does need 12 volts was not sure if there was a resistor wire in the centech harness

 

[KBUCK1]

Even though the original starter solenoid is bypassed for the starter, the solenoid is still in the ignition circuit so the coil gets a full 12 volts during cranking. You'll need to find out if your new distributor needs a full 12V.

Can in not be wired to get the full 12 volts without the fender mounted solenoid?

 

[blubuckaroo]

Can in not be wired to get the full 12 volts without the fender mounted solenoid?

If that's the case, I can't see why you couldn't just eliminate the old solenoid altogether.

 

[Jdgephar]

Hi Kbuck! You should still use the fender mounted "solenoid" or relay to power the solenoid on the starter.

See this wiring diagram:

http://www.supermotors.net/registry/media/870249

The fender solenoid provides a couple "convenient" features. It prevents starter run on, reduces the current flow through your ignition switch while cranking, provides full voltage (bypasses the resistor) to the coil while cranking, and provides a mounting terminal for all of the 12V wires - alternator charging wire, connection to the battery, starter power to the new starter, power to the cab, etc.

The MSD "ready to run" distributors are just a electronic version of a points distributor. It needs 12V positive for power. Very similar to a pertronix module in a points distributor. The MSD website shows the red wire goes to 12V (that should be "upstream" of the resistor, not the + post of the coil). Orange wire goes to the coil -. Black goes to a ground and grey to the tach, if you have one.

The coil + wire should have a resistor. Get the 12V for the distributor from the 12V side of the resistor. The lower voltage side of the resistor goes to the coil +. The resistor is needed unless you purchase a coil that specifically does not require the resistor. The MSD website does not say anything about the module adjusting the dwell time or being able to eliminate the resistor.

As far as wire routing, I run everything to the left side by the alternator and combine with the alternator wires, and then go along the passenger side of the engine bay.

Steve83 has some nice color coded wiring diagrams I've used for reference in the past. I'm sure Viperwolf will chime in too.

 

[KBUCK1]

If that's the case, I can't see why you couldn't just eliminate the old solenoid altogether.

Thats what Im wanting to do. Can the solenoid thats on the new starter act as the old solenoid?

 

[KBUCK1]

Thats what Im wanting to do. Can the solenoid thats on the new starter act as the old solenoid?

Thanks for the reply. I was thinking that I could run battery cable from positive side of battery directly to starter. The purple start wire from the centech harness to nuetral saftey switch and then to starter. The red battery wire from harness to the same terminal as the large battery cable on the starter. Wouldnt the solenoid then function the same as if it were mounted on the fender? all wires that would need a twelve volt source could be routed there or to a hidden terminal close by.I know nothing about electrical stuff. so Im just throwing stuff out there. The starter wouldnt "run On" like this would it. The purple start wire would trigger the solenoid to on and off.. Right?

The diagram below came with the harness and doesnt show another solenoid.

 

[KBUCK1]

Instructions with msd coil say this. Do I use a resistor?

 

[KBUCK1]

Here is instructions on distributor

 

[Jdgephar]

The coil directions state that the resistor is needed. The distributor information does not say anything about current limiting with the module that it has. It is of my opinion that the resistor is required.

The main reason that I would continue to use the fender mounted solenoid along with the new starter is 1) to keep the current down on the purple ignition wire. That huge solenoid on the starter will draw more power than the fender solenoid. And 2) to bypass the resistor for the coil when cranking, since it has a terminal directly for this. 3) Ford continued to wire starters this way at least through the 90s. I'd have to review the centech wiring diagrams and back EMF paths through the circuits to see if the starter solenoid would properly turn off when the purple wire loses 12V from the ignition switch.

 

[badmuttstang]

I run my msd and other aftermarket ignition stuff off straight 12 volts no resistor. The pertronix II I have in my bronco runs threw a relay which the pertronix tech told me would be the best way to run it as it will supply full voltage to the module making it last longer and make use of the full power of the set up was told the same thing by a msd tech a few years earlier when running my ready to run set up on my stroker mustang.
As for the starter solenoid I would leave it as well but if your just looking to make things really clean looking you could do whats called a wire tuck and run all the wires to the back side of the wheel well and hiding everything put the solenoid inside the fender instead of engine bay. Problem is working on something like this takes a lot more time and can be a headache trouble shooting wiring.

 

[Jdgephar]

I run my msd and other aftermarket ignition stuff off straight 12 volts no resistor.

OP isn't running an MSD box. He's running a module inside the distributor. I agree, module in the distributor needs full 12V.

An MSD 6 or 7 box does limit the current to the coil, so no need for a resistor on the coil. The OPs module, in the distributor, according to MSD's website, says nothing about limiting the current to the coil. The coil instructions say that a resistor is needed if the module does not limit the current. I would hate to burn out a new coil, or at least I would find out from MSD directly if the module that he has limits the coil current.

The pertronix II I have in my bronco runs threw a relay which the pertronix tech told me would be the best way to run it as it will supply full voltage to the module making it last longer and make use of the full power of the set up was told the same thing by a msd tech a few years earlier when running my ready to run set up on my stroker mustang.

Agree, the distributor power lead needs 12V.

 

[badmuttstang]

I guess I should have stated I run coils that rated to run straight 12 volts or higher. There is some differences in resistance on what coil you run and could make a difference.

 

[KBUCK1]

Ok, the msd tech line says no resistor needed.

 

[DirtDonk]

And as you may already be aware, the Centech harness does not use a resistor wire. So if you don't see a ceramic based ballast-resistor anywhere in the ignition circuit, you should be good to go with the full 12v from either of at least two wires that Centech usually uses.
One is Blue, the other White, if I remember correctly. Either way, they're marked.

They do include a ballast resistor in their kits, so if you didn't install the harness yourself, just look around for one in case the PO put it in line.
You know... Just in case the PO hid it under the dash in a small plastic box that'll melt and cause a fire just when you're as far away from civilization as you can get!
You know how those pesky PO's can be when it comes to creative wiring!;D

Paul