Briggs and Stratton 311777-0164-e1 electrical problems

[Fish]

You need to pull the keyswitch first and check the posts, on the backside they have stamped the letters indicating what they go to. If you are getting any continuance between "B" and "M' or "G", then your switch is bad. They can be real squirrelly when they start going bad, as those little springs and balls will wiggle around in the switch and short out different contacts each time.

But of course, molten or chewed up wiring is another thing to look for...

 

[Rivets]

Are you saying you remove the kill wire from the coil and you still get a voltage spike on the other wire on the coil? That would be the spark plug wire? The M terminal on the key switch is used to ground the coil when you want to shut the engine down. If you pull the kill wire, M terminal, and hook a temporary kill will to the coil, you will be able to isolate the coil from the system, but still be able to shut it down when you are finished testing. I don't understand how you can get a voltage spike at the coil with the kill wire disconnected? Yes Mr. Fish, I still stand by my reply to the poster in the other thread you referenced. I believe he solved his problem by doing what I suggested, replacing the coil. This poster could have voltage spike coming from the key switch, but once the kill wire is removed there is no way for the current to get to the coil. He is asking for possible solutions and how to pinpoint the cause, not a debate. If he thinks that I have him going in the wrong direction, all he has to do is say so and I'll let you help him without getting in the way.

 

[clemsonnum1]

The keyswitch is fine. Brand new one on there and tested as well. I'm getting voltage through the kill wire that leads to the ignition coil. I'm not getting a voltage spike at the coil, just at the kill wire that is supposed to hook up to the coil. The coil isn't even on the mower right now. In fact I took the entire wiring harness out to look for problems. Today I hooked up the solenoid directly to the battery and wired it so I could engage it by touching a wire to one of the terminals. The weird thing is I'm getting 0.27 volts going from ground to ground. I bought a new solenoid just to see and it does the same thing. When I remove the the wire from ground it spikes up to 7-8 volts before going back to 0. This is with nothing but solenoid and battery. Is 0.27 volts enough to fry an ignition coil? That is constant when the solenoid is engaged and then spikes when removing one of the two ground wires. I thought for sure it had something to do with the solenoid because I only get voltage while turning over the engine and releasing the key into the run position. No other voltage readings going from off-run/lgts-run.

 

[Rivets]

According to the wiring diagram, the kill wire runs from the M terminal on the key switch to the terminal on the coil. There are two non removable connections on this wire, one from terminal A on the PTO switch and the other on the clutch/brake switch. This means to me that to get a voltage spike on the coil end of the kill wire, voltage must come from one of these three terminals. M terminal on the key switch, A terminal on the PTO switch, or unmarked Black wire on the clutch/brake switch. This is assuming that there are no other shorts in the wire. Remove one terminal at a time to isolate the source.

 

[clemsonnum1]

Thanks for all the info. I'm going to repair a couple nicks in the wire and then secure the wiring harness and reinstall with the new solenoid and take a new reading with everything reattached. I don't think the nicks in the wire are the problem because they weren't crossed with anything. My question is how do I remove these terminals one at a time and still get the solenoid to engage? Everytime I've unplugged a terminal it breaks the circuit and won't allow me to do anything. I've seen a couple videos of people removing the nonremovable plugs as well. Looks like a pain but better than having to buy a new wiring harness. Also is 0.27 volts enough to fry an ignition coil?

I went and talked with a local authorized husqvarna guy and he told me it's a crapshoot and time to buy a new mower So basically start replacing stuff until I find the the problem or buy a new mower are the options he gave me.

 

[Fish]

Hopefully I have guessed the correct model number, post the model number off of the tag under/behind the seat for confirmation...

View attachment HUSO2000_USen_O0002008_ wiring scheme.pdf

 

[Fish]

Oooops, no wonder it took a while to load!!! Page 29 for the schematic.

 

[clemsonnum1]

Update:

I found a problem with the lights ground. With the lights on I'm getting around 225-275 mv through the ignition switch ground terminal. Also there is a black plug with a black and red wire which runs to the clutch. The black wire had been cut previously and repaired but the wire came loose when I was messing around with it. So I fixed it, but it came loose a bit again so a little copper was showing. I took a reading and got 8.9v coming through it with the blade engaged and 9.3v on the red wire. With the blade disengaged nothing.

Edit:

I have a 4 post solenoid (brand new one). I'm getting voltage when I engage the solenoid on what is supposed to be the ground terminal (2 black wires plug into it) according to the wiring diagram.

 

[Fish]

So you have stopped burning up new coils then? Just leave the kill wire unplugged if you are not sure!!!!

 

[clemsonnum1]

I ended up just installing a toggle switch and running new ground wires. However, that didn't solve everything because I was still get some voltage through the dash so I put some liquid electrical tape on the switch so it wasn't touching any metal. So far that has solved the problem and no more burnt out ignition coils.