Dual Trigger Ignition - Wiring Diagram

[TheJet-09]

Does anyone have a wiring diagram, or info on where to obtain one for a dual trigger (crank trigger and distributor) MSD ignition?

I don't expect anything for free (other than maybe opinions), but I have had no luck in searching MSD's website (most likely due to my limited computer skills). I also see MSD has a book and CD containing wiring diagrams, but I wanted to be sure what I was looking for was a part of them before purchasing one.

Thanks in advance!

[billetbirdcage]

Does anyone have a wiring diagram, or info on where to obtain one for a dual trigger (crank trigger and distributor) MSD ignition?

I don't expect anything for free (other than maybe opinions), but I have had no luck in searching MSD's website (most likely due to my limited computer skills). I also see MSD has a book and CD containing wiring diagrams, but I wanted to be sure what I was looking for was a part of them before purchasing one.

Thanks in advance!

http://forums.pelicanparts.com/uploads22/msd+6+digital1368418081.jpg

[billetbirdcage]

[petesbuyin]

If you are running a single box-single coil with a dual trigger(distributor & crank trigger) then all you need is a QuickCar switch #50-420. It has 3 pair of terminals (6 total).

You wiring it by running the green-purple trigger wire from the box to the center pair of terminals on the switch. Then run the crank trigger to one of the remaining set of terminals on the switch, and run the distributor to the other pair of terminals on the switch. When you have the switch in the up position you will be running on one trigger source (say distributor) and when you put the switch in the down position you will be using the other trigger source (say crank trigger).

Be sure to have the wiring colors matched correctly -
Distributor orange to box purple. Distributor purple to box green.
Crank trigger purple to box purple . Crank trigger green to box green.

That is my 2 cents of information. You can put the payment in the mail.

[Matt49]

Can that 2 cents be paid in installments :-)
Jet, not sure if you picked up on it from MSD's website but once you are on the page for the product in question (not sure what box you're using) the default information is the "Overview" and then there are tabs, one of which is "Tech Resources". This has a link to the PDF instruction file the includes all of the various wiring scenarios like what billet posted above. Best of luck.

[TheJet-09]

Excellent info from everyone. Thanks!

I was hoping to stick with a single box (6aln is what I have now) and coil, but we'll see. From what I understand of the engine I picked up, the crank trigger has more timing in it than what the distributor is set at (so I would switch to the distributor to take some power away).

So while on the subject, is it okay to switch from the crank trigger to the distributor while the engine is running, or should the engine be off when changing?

Thanks again!

[TALON75]

You can do it while running no problem.

[JustAddDirt]

msd 7990 switch.
allows 1 msd box, and use of crank trigger and distributor. each with 2 timing profiles.
works great.

[TheJet-09]

Excellent! Thanks again to everyone for the information!

[dirty white boy]

what is the reson some body want both wired up on switch for??? what the benifet?

[billetbirdcage]

what is the reson some body want both wired up on switch for??? what the benifet?

If max power is at say 36 degree's timing, then one is set for 36 and the other might be set 4 to 6 degree's retarded to reduce power for the slick by flipping a switch. Least that is the most common use of one.

[dirty white boy]

that makes since,...thanks!

[JustAddDirt]

Billet and grt74 are both right. That’s why I run that setup.

[TheJet-09]

So for those who have or do run this type of ignition, does it make a noticeable difference when taking timing out in the slick, or do you have to take power out other ways as well (like with a restrictor spacer)? I know all engines will vary, but just curious if it alone is enough.

[JustAddDirt]

See the glow

i know there are guys that do this but im not a fan of it, there are other ways to kill power with out fooling with timing, and the reason i say this is heat build up in the engine when you back off the timing, if for some reason you start to run wide open with the timing backed off, it will create a ton of heat, you ever see glowing headers !!! never a good thing

You are correct it does build some heat, but if I need to run wide open I go back to the standard timing. I use it on restarts in the slick, and if I am slow rolling the bottom . If I am really on throttle, I am on the standard timing.