Export thread

Briggs Intek on a JD 125 Riding mower.
No spark. Friend brought it over. Got it running. All was good.
Saw a mouse chewed on the coil black wires. Repaired and replace the wire.
Put back together. NO Spark.
Disconnect the black wires from the coils and we have spark.
Checked the new wiring. With a multimeter checked the parking brake switch, seat switch and PTO switch.
Found nothing.
Still no spark.
Disconnect coil black wire snd we have spark.
Ideas?

The black wire grounds the coil when you turn the key off, either there is a crack in the insulation and it is grounding to the frame somewhere
It may also be something with the ignition switch... not sure on that.

Remove the kill wires from the coils. Turn the key to run position. Check continuity between end of kill wire to ground. If you have continuity your short is in the kill system. Then remove plug from k switch and recheck for continuity to ground. If you still have continuity to ground, your kill wire is probably the cause. No continuity then your are going to have to test the key switch and safety switches.

Rivets said:

Remove the kill wires from the coils. Turn the key to run position. Check continuity between end of kill wire to ground. If you have continuity your short is in the kill system. Then remove plug from k switch and recheck for continuity to ground. If you still have continuity to ground, your kill wire is probably the cause. No continuity then your are going to have to test the key switch and safety switches.

Click to expand...

We have No continuity. We haves tested the seat, brake, and PTO. Each switch showed contacts opeing and closing.

You have NO CONTINUITY on any of the tests I posted? You did every test?

Rivets said:

You have NO CONTINUITY on any of the tests I posted? You did every test?

Click to expand...

Correct. No continuity on any test. We just tried again.
We get continuity when leads are touched together.

With the kill wires off, but the switch in the off position, do you have continuity?

Still No continuity with ignition off and both kill wires off the coils.
One coil wire in air, lead connect to other coil wire. Other lead the neg on battery.
Still reading 1 on multimeter set to ohms

Thanks for helping. Ill keep following your suggestions

Jamie

Something is not right and I think I know what. If you are doing these tests by attaching one lead to battery ground, you will not get what I like as a valid reading. Do the tests with one lead going to a good engine ground. Don’t worry about PTO and safety switches at this time, as we are just looking at the kill circuit. Before starting this test remove the negative wire on the battery.

I just went through it all again from the first post with neg remove and grounding on engine block. No change

Just checked the spark again.
Nice spark on both plugs with coil black wires removed.
No spark with black wires on coils.
Parking brake on. PTO off. Sitting on the seat.

Wait a minute, I just reread your posts and I missing something important. A reading of 1 is continuity, a reading of infinity is no continuity. Do you understand that?

My apologies.
I was understanding probes touching together is continuity. Reading 0.
Probes not touching reading 1 etc is a break or no continuity.

Looks like i was misunderstanding.
So a reading of infinity or 0 is continuity.
My apologies.

No, No, No. A reading of 0 is continuity, there is NO resistance, meaning current can pass through with ease. A reading on infinity is NO continuity, meaning that there is so much resistance that no current can pass through. You are going to have to start over from the very beginning and forget EVERYTHING you have seen to this point, because EVERYTHING you posted is meaningless. I would quit for today and start over tomorrow, with a fresh, clean starting point. I hate to say this, but an assistant who understands electrical circuits would help you a lot.

Good idea

SOLVED
Ended up being the new wire i installed.
The original coil Black kill wire has diodes in it to prevent the coils from interfering with each other. I patched together the old wire and all is good.

I just use the diode test on my meters. Beep for good circuit, silence for an open circuit. Real handy when testing in close quarters or around running equipment.