Scag Ignition Relay

[StarTech]

KInda figured the PO might have done that. People think safeties are there to be a pain. It is like those bypass the mow in reverse inhibitors. Since 2009 I have heard of two cases in my area where toddlers have been ran over by the mower operator. One resulted in the child death and the other the little girl lost part her foot.

I simply will not bypass safeties and customer that want me to do it can go somewhere else.

 

[Hayward51]

KInda figured the PO might have done that. People think safeties are there to be a pain. It is like those bypass the mow in reverse inhibitors. Since 2009 I have heard of two cases in my area where toddlers have been ran over by the mower operator. One resulted in the child death and the other the little girl lost part her foot.

I simply will not bypass safeties and customer that want me to do it can go somewhere else.

I have ordered the seat switch with bracket. I won't expect it within a week (hopefully sooner) but I most probably will be back here with questions and to let you know how it works out. Thank you for your input, Star Tech.

 

[Hayward51]

Currently according the schematic Scag is using (feeding) 12v through safety switches and the interlock then converts this to a grounding circuit for the starter relay. In order to delete the interlock module the system would need to be converted to a grounding system.

This requires removing the red jumper wire from pole C to pole A on the PTO. Now disconnect the lt blue wire from the other pole C terminal and attach a ground to the terminal. Now at the interlock module disconnect the Orange, and the Green/Black wires. Tie those two wires together. The only left is get the seat to kill ignition if you are off the seat. This would require disconnecting the Brown and White wires from the interlock module and tying them together. Note don't do this unless the circuit is converted to a grounding or you will fry your ignition coils but only if the brake switch is activated. But I would prefer the seat to kill the engine anytime you are not on the seat so I remove the red wire at the seat switch and attach a ground to the ground terminal. This way whenever the operator is not present the mower will not run. (just in case operator get knock off the seat when mowing). And yes I had one customer that had someone to mis-wired his mower, it did happen, and the mower took out his wife's new car. Let's there was someone hunting him.

View attachment 67902
Quite easy to do when you know what you are doing but can be confusing to those that don't. So please don't try this unless are 100% sure know what you are doing.

Star Tech, One major question on my mind (yes, it's confusing), when you say "don't do this unless the circuit is converted to a grounding", what exactly determines that the circuit is grounding ? I'm assuming it's the rewiring of the PTO switch. ?? I just want to have this part straight in my mind when I get the seat switch installed.

 

[StarTech]

It means you do not to be applying to the ignition coil kill terminal. The enclosed electronics will not survive if you do.

This why the 12v jumper is removed at the PTO switch and then the terminal is connected to ground. Items in red are the changes at the PTO switch.

 

[Hayward51]

It means you do not to be applying to the ignition coil kill terminal. The enclosed electronics will not survive if you do.

This why the 12v jumper is removed at the PTO switch and then the terminal is connected to ground. Items in red are the changes at the PTO switch.
View attachment 67913

I'm sorry to seem too dense to comprehend your reply but, "means you do not (x) to be applying (x) to the ignition coil kill terminal", sounds like a word or two are missing in this statement.

 

[StarTech]

I'm sorry to seem too dense to comprehend your reply but, "means you do not (x) to be applying (x) to the ignition coil kill terminal", sounds like a word or two are missing in this statement.

Sorry I forgot to proofread my post. I do have a bad habit of thinking faster than I type. Plus I am on a fluid restriction so I hadn't my coffee yet. It had to manage 1.5 liters per day.

It means you do not to be applying to the ignition coil kill terminal.

It should read "It means you do not want to be applying 12V to the ignition coil."

 

[Hayward51]

Star Tech, I got my seat switch in and started my rewiring of the Scag. I read thoroughly and when I got to the seat switch part, I found I have 2 RED wires and a BROWN wire going to the switch. One red goes to hour meter and one red goes to the PTO switch. I had 12V on one of those red wires before I rewired, now none. I connected the terminal C (lt blue wire) to ground, turned key ON, and blew a fuse. I noticed the seat switch wiring on different year model diagram (SN 9260001-926999) is the same as my harness wiring. This threw me ! Could the PO have used another harness be the reasoning behind hacking the wiring ??

 

[StarTech]

It possible but it should not caused the problem.

Okay I might missed a wire here. Try simply disconnecting the interlock module. It might be that the pink wire is causing the problem at the interlock along with the hour meter power feed.

It looks like they might rewired the hour meter to get it 12v thru the interlock and the seat switch. Unplugging the interlock should stop this. Note the interlock module is the same on both SN.

 

[Hayward51]

It possible but it should not caused the problem.

Okay I might missed a wire here. Try simply disconnecting the interlock module. It might be that the pink wire is causing the problem at the interlock along with the hour meter power feed.

It looks like they might rewired the hour meter to get it 12v thru the interlock and the seat switch. Unplugging the interlock should stop this. Note the interlock module is the same on both SN.

When I got to the part about grounding the red wire at the seat switch is when I noticed I had 2 red wires. That part was most confusing of all. How does that switch work if disconnected ? And is it necessary after disconnecting module ?
I disconnected the interlock module turned key ON, blew another fuse ??

 

[StarTech]

Boy do I wish I was at the mower myself. So hard to explain things remotely. Something is still connecting to +12v which getting grounded and blowing the fuse.