Lawn Mower Electrical Troubleshooting

hi this is Edie from right here we're going to talk about some electrical systems electrical systems can be a real mystery to a lot of folks and so we're going to take an overview of how the system works in general we're going to talk about all the different components in the system and then in the end we're going to look at some specific Diagnostics if you're looking diagnose a specific thing go ahead and jump to the end but let's dive right in and look at how this all works all right real quick before we get started we have a live system here we want to talk about a few safety things first off you don't want to be wearing a ring metal watch anything like that because if it were to become the path of electricity could instantly become glowing red hot and you could be burnt by we don't have a lot of voltage so you're not going to necessarily get shocked by the system very easily but that amperage if it's short-circuited can lead to something getting real hot real quick the other thing is that because we're dealing with the live system the engine potentially start or run you want to be sure all the shields are in place that you're in a safe place relative of the machine and that you're generally aware of mechanical systems and that you know you're you're set up for this now the other thing is that if you're going to disconnect the battery you don't want to take the positive off first this is a little counter into but if you were to put a wrench on this positive post here and unscrew this and the ranch were to hit the framing machine would arc you'll want that so you want to disconnect your ground first so that you have an open circuit and then a wrench wouldn't arc off of here and then when you put it back on you want to put the positive first and then the ground so there's a few ground rules just to be aware of because when you're doing Diagnostics and you're not familiar with what's going on it's very easy to forget something to keep those things in mind all right we're going to go through the major components of the system first here we have the battery this is a 375 cranking amp battery or a 300 cold cranking amp battery some of the big-box stores sell batteries that look like this and they're but they're lower amperage rated for smaller engines you want to be sure to get a battery it's capable of your machine all the starts it's going to be going through you don't want to have issues with the battery dying prematurely so then we have a ground wire goes to the and these are sturdy solder depth battery cables here we have the positive goes to the starter you may have a solenoid beside the starter like this instead of going straight to here but these are your main connections nothing will work correctly if either these are loose you they have to be well connected then we have our wires going into the harness you have our ground of the harness or battery positive to the harness component wise we'll start down here actually all the way down by the carburetor there's a solenoid here it make that clicking noise and what that's doing is its opening up the fuel flow into the carburetor turn the key off shuts off the fuel flow here we have the regulator so this charges controls the voltage to charge the battery the yellow air coming off of it leads the battery the two here that come from the flywheel that's from this debtor that AC power going into this regulator we talked about the starter for a second so the starter here has a solenoid in here so it's a big contact or switch when it's actuated that plunger drops down there's a rocker arm in here and it throws a gear into the flywheel so those positive engagement this side is the motor green wire is what energizes there engages the starter going into the harness here we call this a pigtail it's the first connector on the harness and these wires need two different components in the engine this Kawasaki pigtail fits just about any Kawasaki engine of powered motor we've built over the years we also have other pigtails for example this one is for a Kohler and it's actually common on EFI engine to put a diode here because what happens is when you send power to something like the clutch like this right here and this clutch disengages it sends a high voltage spike for good you know milliseconds back into the system and that could potentially damage some of the computer components now they do have isolation built into the ECU there but we put extra isolation on this sighs machine so that's a diode there and it's just connecting between the ignition and the ground and if you know it won't ground out the ignition normally but when that spike comes back through the harness its polarity is opposite and this kills that spike this pigtail can also be used to repower any kohler engine even if it's not an EFI this goes on the ground by the engine this connects to Kohler this connects to the right harness we also have a Briggs pigtail similar to that for some of the newer Briggs engines for converting them over so that's the pigtail component here going up into the harness let's first follow the battery positive so battery positive goes through a fuse and goes up to the key switch we have the charge wire which goes through fuse and also goes to the key switch now it can be a little intimidating when you look at a harness like this you see all these wires oh man what's going on here but what's crucial let's look at your schematic and it's not really that complicated because there's some things that really help you understand this so like we talked about the purple goes to the key switch and then from the key switch we have these orange wires here when you turn the key on connects the battery to the orange that's our ignition circuit and that orange wire just daisy chains everywhere through the harness so anywhere you see orange that's your ignition circuit you should when your key is on you should have positive power 12 volts at all your orange terminals we also have other circuits in here like the green circuit so this green circuit is for start when we turn the key on energizes the green wire goes the blade switch so if the blade switch is on it won't let us start the engine you have to have the blade switch off you wouldn't want to start the engine with the blades on then it goes through brake switch so you have to have the brake on to start the engine that green wire comes here to the starter post there's several other circuits in here but the real principle there to understand is that a lot of these wires daisy chain through the system and you got to follow the schematic if you take a highlighter and just follow the power from the battery or whatever point you're working on trace it back make sure you know you're getting power we need to go as you go upstream both the ground side in the positive side you have to follow up up both them up to where you think you may have a problem some of the other components besides the harness we have a key switch here so this is pretty common for a lot of different machines some machines don't put their charge to the key switch some go straight to the battery post we have the purple coming up here so we're in the off connect position the purple is not connected anything and this white kills the engine connects it to the black ground wire here so when we're off the white black are connected and the everything else is open when we're in the run position the purple will be connected to orange so that's our ignition and it'll be connected to yellow which is our charge so charge the ignition the battery all connected together and the white wire is open it's not grounded out so the engine can run we go to start very similar except for we'd energize the green wire to crank the engine so that's the key switch the our meter is just your positive and your negative to energize the our meter we have a relay which is the clutch relay turns the clutch on and off we have a PTO switch which has several circuits in it like we said the green wire is your starter interlock the ignition wires and the keys on gives us power here we turn the switch on it energizes this purple wire and then over here this is actually a time delay override on this and here so that's your your blade switch your brake switch here we have our platform switch so on a write mower our safety switches in the platform makes it very intuitive to operate the machine verses one in your and your handles so that's a pretty straightforward switch there so overall that's the system I will talk about the clutch for a second so clutch has a positive and a ground going into it as electromagnet and when it energizes it pulls that plate up against the rotor of the clutch engages the blade so that's our major components if you have a remote solenoid you have something like this and you'll have one post going to the battery and now they're going straight to the starter and your green wire energizing it and it must be ground but this isn't grounded through the fastener through a ground wire to the frame or to the engine it won't work correctly so that's the solenoid so overall that's some of the main aspects of the system let's get into some of the troubleshooting that you may need to do on your machine so there's a few things we can talk about first off would be a no charge situation no charge situation means that you may have jump-started the machine it runs when the battery dies pretty quickly again and it's just not holding a charge it could be that battery has just been drained too many times and the plates have become to the point where they won't properly work these are sealed batteries so you shouldn't have to be opening them up to fool to acid or their service crew batteries are not sealed but their service free so could be your battery when you're looking at batteries big-box stores sell battery it looks a lot like this but you want to be sure you have the original amperage that the motor manufacturer had for the battery just because the case looks the same doesn't mean that battery is made for that machine and if the battery is not big enough it may work at first but it's not going to last very long that battery will die pretty quickly so you want to be sure that your ground and positive are connected well here nothing's loose because if you had a loose ground either on the harness or the engine that charge is not going to work correctly and you know there might be enough of a ground connection where arcs and let's the engine start but it won't let the regulator charge the battery so make sure these are good check your yellow wire make sure it's plugged on there well it's plugged in the key switch well any disconnect to the yellow wire check the fuse be sure all that's intact it's easy to do the visual stuff so you want to do all the visual stuff right away so if all that checks out then you can use a multimeter to just be sure what's going on so multimeter you are set it to voltage connect to the battery and if you get 12 12 and a half volts that would be battery voltage less than that would be a battery that's starting to die the charge system is going to give you 13 volts or higher 13 to 14 volts 12 and a half means your regulator is not working 13 means a regular is working 13 and a half it's working good so measure voltage there at the battery and you'll know whether you're getting a charge the battery is just not taking that charge so you can easily do that now if you're not getting a charge here and all your circuits check out you can do a continuity test like you can do a continuity test from your charge point here you disconnect it and check the continuity back to the positive post you have continuity you know the harness is good you can do a ground from here to the ground of the regulator make sure you have a ground connection to it but that all checks out you're still not getting a charge then there is a way to check the static oil inside here you can disconnect the connection here and you're looking for AC power there coming off that and you'd want to look at the engine manufacturers service manual for specifics on what voltage what engine speed you're looking for there that can be checked too that'd be a no charge situation a few of the things to look at also we have an accessory connection here so if you have an accessory that's drawing too much power and it can't keep up with it that could also be an issue so just be aware of now a few other things could happen where you can have a situation where the engine may start and run but you engage the blades and nothing happens well first off there's two scenarios one is that you pull the blade switch up and the engine dies pull this engine dies that means that one whole half the system would dish you'd be in one half of the system if you pull this and the engine doesn't die then you know that it's towards the clutch side of the system so let's first talk about that situation where it might die if you pull this up and the engine dies that means that the safety switch is not releasing the kill relight so things to check there are the red wire going back up to the time delay making sure that's intact the switch needs to be working correctly check the terminals going into the relay the relay itself could be bad and one thing to note about that we like is although this is similar to a standard automotive relay you want to use the original OEM relay here because there is this is a heavy duty potted relay any ones that are open they're not going to last very long but also there's something here that will actually suppress the spike when it's turned off and if that's not there it can burn out other components are qug ends contacts and other parts of the system so you want to be sure to use the original relay there so it could be a relay issue now if you pull the switch and the engine doesn't die and then blades still don't come on then that means that there is probably an issue with either the blade switch or the power going down to the clutch so if the engines running we assume that we have an ignition here at the orange you can check that but this blue wire should be sending positive down to here to the red wire and that can be checked with a multimeter and then you can also follow your ground back so your ground here comes up to the relay make sure that the relay is sending a ground down there now you could have don't dismiss the fact that you may have a mechanical issue when the clutch where's the gap in here increases and if that gap gets too big the clutch won't actually pull in and we have another clutch video goes some specifics about how to diagnose the clutch but that's one thing to realize you could also have potentially a broken wire or something in here the coil could be burnt out and you can measure resistance on the clutch coil to check what state it's in again check the clutch video for more on that it's uncommon but you could have a time delay that needs to be replaced they're difficult to diagnose but if nothing else checks out it potentially could be a time delay now a lot of sit down mowers may have a time delay some of our standout mowers have a time delay our newer machines we've actually gotten rid of it because just with the stroke of the platform we've eliminated a lot of the clutch clicking on and off situations and anytime you can eliminate a component makes the system more reliable so some of newer machines actually don't have this all right so that would be a no blade situation now you can also have a no start situation we've talked about a lot of the starting components the green wire is this is the start circuit we have a brake switch here one easy thing is if if somebody pulled the blade switch on Africa machine is parked there and you try to start it put the brake switch down nothing happens right so just check this real easy make sure the blade switches off yeah so we got a live system there you have to have your brake switch down the start circuit it's your purple wire going to the key switch and from your key switch your green wire going to your clutch switch brake switch back to the starter so things to look for are these switches for the starter you can actually tap on the starter beside the solenoid or the starter motor if anything's frozen up in there don't hit it too hard because you can't break the magnets loose inside here create other issues but sometimes tapping on the starter works as a temporary field fix to get it going that's easy to do now if the whole system checks out you're getting powering your green wire you have a solid ground solid connection then it's most likely going to be your starter motor so that would be a no start situation any I hope today's video helps you understand a little bit how your electrical system works some of the things to look at you know I tried staying general enough that it comply could apply to most any brand mower but the important thing is to get your schematic out and look at what's going on so you want to follow your ground wire and your positive wire to wherever you think that the system is not performing correctly get a highlighter trace that out and just think it through you don't want to throw parts of the system just to eliminate possibilities but I would say that be careful how much time you put into diagnostics when we look at warranty work at dealers if the components are proven out and the harness is not working it's really not worth opening up a harness typically for the cost of a harness versus the Diagnostics it ends up being less costly just put a new harness in there guaranteed everything to be original like the factory so be cautious about putting too much time into the system you got to think it through carefully but also move on if you know what components or you think that it's one of two or three components and if they're relatively inexpensive just go ahead make it work make it good because time becomes very expensive diagnosing the electrical system that's where your expertise as a technician or your ability diagnose what's going on can go a long ways you can save a lot of time if you really understand what's going on here so think it through hopefully this helps you if you broken down in the field you know a few things you could check for or as a technician a better understanding of how a right lawnmower type electrical harness works thanks for watching

Channel: Wright Commercial Mowers

Views: 354,716

Keywords: stander, lawnmower, troubleshoot, electrical, jumpstart, wright mowers, wright stander, starter, switch, clutch, kawasaki, kohler, briggs, diagnose

Id: _UphstihZeA

Length: 19min 0sec (1140 seconds)

Published: Fri Sep 02 2016