Msd 4270 starter relay hook up ?????

Sasquachcrap · Sep 18, 2014

Can some one please help me. I am trying to wire my msd enclosure and I don't understand the starter relay hook up. Here are my instructions.

Why do you hook the two green flywheel wires to the switch I have a brown and red coming out of the switch. Red is power and the brown goes to the solenoid. Im stumped and steering at these instructions isn't helping.

Dartman · Sep 18, 2014

Has been a long time since I did one. Take the red from the box and skip the lanyard switch in the diagram and go to the on/off switch.
Yamaha lanyard is the black and white for the kill and the start is red and brown is for the start relay.
Red from batt/fuse to switch red and brown to the relay small post. Make sure the relay is grounded on the other small post.
'T' into each green (2) from the pickup going to the box.
Connect one green to the white and connect one green to the black.
This will kill the engine when you pull off the lanyard by shorting the 2 pickup greens.
Just make sure you ALWAYS turn off the on/off switch as soon as you can when you stop riding.

Sasquachcrap · Sep 18, 2014

@Dartman. Thanks so much. Why change the way the on of switch Is wired in.

Philip Clemmons · Sep 18, 2014

If you have violet on your brain, it needs switched 12V. Pier the switch from the battery, and connect the violet to the other side of the switch. The red on the s/s switch should come from a fuse on the bat, and the brown should go to one small relay terminal. Ground the other relay terminal. T into the pickups as Dartman said.
Hope this helps.

Sasquachcrap · Sep 18, 2014

Thanks so much guys. I just finished and tested it. All works great. I did have a violet so I ran switched power to it. And teed the greens to the white and black. What size fuze should I run. Here's a pic of it all together in my home made enclosure. The front is lexan but its not finished quite yet.

. I used a silver vein powder coating on it, so maybe it will look good for years to come.

jetpilot36 · Sep 20, 2014

nice box!

Sasquachcrap · Sep 20, 2014

jetpilot36 said:
nice box!

Thanks. Here's one of it complete.

Jordancaird · Sep 22, 2020

Dartman said:
Has been a long time since I did one. Take the red from the box and skip the lanyard switch in the diagram and go to the on/off switch.
Yamaha lanyard is the black and white for the kill and the start is red and brown is for the start relay.
Red from batt/fuse to switch red and brown to the relay small post. Make sure the relay is grounded on the other small post.
'T' into each green (2) from the pickup going to the box.
Connect one green to the white and connect one green to the black.
This will kill the engine when you pull off the lanyard by shorting the 2 pickup greens.
Just make sure you ALWAYS turn off the on/off switch as soon as you can when you stop riding.

Hey I know this is an old thread
I have hooked up my msd according to how you explained it worked great and then as I went to start it it's just clicking and not turning it over so I changed the starter relay and that did nothing now I notice when the lanyard is in it cuts power to the box and the light goes out and it still won't roll over
Any suggestions?

Sasquachcrap · Sep 22, 2020

An MSD brain doesn’t care whether your starter solenoid is on or not. If it’s not turning over its not because something in the brain is not telling it not to. it should be because either the start stop harness is bad or the solenoid or the starter or grounding wires or cables.

Jordancaird · Sep 22, 2020

Ya I I know but when the lanyard is inserted it's cutting to the box that's why I think something with the switch or could that be a ground wire loose that's doing that

Sasquachcrap · Sep 22, 2020

Un plug both switch plugs and test by jumping the brown and red.

Jordancaird · Sep 22, 2020

OK and if that's not it I've got a bad wirecuz relay cuz even when I cross the silanoI'd it's still not cranking

Sasquachcrap · Sep 22, 2020

Whoa, if you’re jumping the solenoid
and you have a good battery then either a wire is bad or your starter is bad. I missed the part where you said you were jumping the solenoid

Jordancaird · Sep 23, 2020

OK so I had a pice of a clip that broke in the starter I've got that fixed but there has to be something with the switch still cuz if I put the lanward in its making the lite on the brain to go out and if I hit the stop botton the light comes bak on any ideas or suggestions

Msd 4270 starter relay hook up ?????

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