rewire of Murray rider

I'm trying to rewire a Murray riding mower Model is 42819X8A.
I have some basic questions about what the wires go to. It worked last year, but toward the end of the year, it started having problems. Now that its time to use, I am trying to get it functional again. The wiring is horrible, I bought this second hand from someone, and the wiring has been modified lets say.
I have a wiring diagram for it that I was able to DL from the web, it is somewhat helpful, but I'm trying to make it more crude.

There are two wires from the flywheel into a connector, one was hanging open not connected to anything, and the other went to the ignition switch terminal and then to the B+ terminal on the solenoid, so it would be hot all times.
Trying to figure what the other one should be connected to?

The next is the blade engage switch. There are 4 connectors on this, the yellow goes in one and out the other, I think there are a set of contacts in series with it. The black also goes through this, same thing, series, then goes to the solenoid to the trigger. By seeing this, it leads me to believe there is B+ going through this side, and B+ going through the safeties?

The carb bowl also has a connector on it with a black and white, the black jumpers to the block maybe 4 inches away, the white looks like it goes to ignition possibly? It has 3-4 butt splices in it as well, all just to lengthen the wire.

The mower has headlights, a red and a green, I moved these wires aside as headlights are fairly easy to get connected. When I get the mower to crank/start and turn on and off, I can connect the headlights.

I'm sure that I'm making this more difficult than it should be. I don't have a lot of experience with wiring on riders. Cars and other stuff I can do no problem, mowers with safeties are a new to me and a pain.

Can anybody give any input on one or more of my above mentioned issues?

Thanks!

 

In the wires coming from under the flywheel, one has a black bulge in it right at the connector. This one is the one that goes to battery positive. It's the wire that charges the battery. The other one is an AC voltage wire that runs the headlights when the engine is running.

The blade switch works in conjunction with the clutch pedal switch and seat switch, allowing the engine to crank when the clutch is depressed and blades are off, and allowing the engine to die if someone is off the seat with the blades on. Two of the 4 contacts make contact while the other two disconnect in one position, and visa-versa int he other position.

The wire going to the fuel solenoid that isn't grounded should get 12 volts from the keyswitch while cranking and in the run position, and get no voltage when the key is turned off.

 

Got this mostly back together tonight. I'm curious about this fuel solenoid on the carb though. Is it supposed to get power from the ignition, or is it supplied power by the generator once the engine starts to turn?
I ask because if I put power to it, jumpers from battery then it will start. If I connect it like the diagram shows it doesn't start.

Ignition switch is being a pain in the butt. The diagram shows letter for each connection but the switch i have doesn't have all the same matching letters.

 

The fuel solenoid gets powered by battery when you turn the key on, independent of the engine. The diagram shouldn't show it being powered by the stator.

 

Ok, I thought it may be a type of safety. When the engine runs the circuit would generate the voltage to close the solenoid. Engine stops due to open circuit and the solenoid would open. I'll try to get a way to power it with ignition on setting.

 

Without any other accessories, that one (without the diode) is AC and intended for the headlights; but it should be through the ignition switch.

The one with the diode (which changed the current to DC) is used to charge the battery; but also through the ignition switch.

Your unit apparently has two (2) solenoids; one for the starter, and one for the fuel line.

I recently wired up a Murray type rider (AMF, AYP, Dynamark, Noma, Turfmaster), converting it from a recoil starter to electric start with a battery, and had to begin from scratch . . . . so I found the ignition switch to be central. Read or decode the rear of the switch and the intended purpose for each of the 5 to 7 connectors on it.

You should be able to find an original wiring diagram online for how the manufacturer intended your unit to be wired; but having the correct ignition switch is critical.

 

Yep, I found a diagram that was similar but not exact. It didn't have the fuel solenoid on the diagram. We did basically make the new wiring on our own based off the key and sheet with diagram. I had bought a new switch, the same as what was on the mower because I thought that was the problem before doing all the crap. Not so much.
The diagram shows a 92377 I think, which had 6 terminals, but mine had 7 terminals. So I bought the 6 terminals one thinking we got this going, just need the right switch, move our wires over and it will go, but still didn't work out. I found the battery shot too, so we had a charger on it to do this monkey business testing yesterday. The new key switch, event though the same part number as what the diagram shows doesn't seem to have the same layout as the diagram. I have an L or my switch but no X. Using a meter trying to find something on the switch that rings out with L like the battery shows. We will see what happens after I find a switched ignition for the solenoid.

 

Decoding the switches can be fun until a mistake is made.

One mistake I made was to send a hot lead to my magneto when it was supposed to be a ground for the kill circuit on the ignition switch, and I burned out my ignition coil. I've seen them with a separate circuit for the Cigarette Lighter . . . . but that seems to have been discontinued (for the moment).

"L" is possibly for Lights; especially if you have no "X" which sometimes means Accessories (which may also be abbreviated as an "A"); but that "A" should be reserved for Alternator.

The manufacturer of that Switch should have provided an explanation of what each terminal meant to them . . . . that's what matters.

 

Yep, the switch is the puzzler.
Nothing with it, but thanks for the idea, I will look it up on their site and see if there is anything.

 

Is this your new switch:


Is so, then I'd GUESS, that moving clockwise:

G = Ground;
S = Starter Solenoid;
L = Lights;
M = Magneto (kill circuit);
B = Battery (hopefully fused at 10 or 15 Amps with in-line Ammeter?, and any safety switches);
X = Accessories.

I would hook your Carburetor Solenoid to X, so that the fuel line is open and fuel is allowed to flow anytime the Ignition is ON, and closes when you turn the key to OFF.

I'd double check each item individually to verify the positioning; but I think this was the end result of my creating a wiring harness from scratch using what was probably the same switch

PS: But I'll have to go out and look to see where my Alternator is connected, as it has been keeping my Battery charged for a couple years, and it's not clear on the backside of your switch where that connection would have been appropriate.

What was the 7th (seventh) terminal labeled as on your old switch ?

 

Thanks for the breakdown. I have a schematic from the Murray manual that we started following, but then found out it had the 7 terminals as mentioned.
The diagram is at the shop, I'll grab it and post a picture when I get a chance.
Meanwhile, I'll try how you suggested hooking it up. Either way, both are at the shop so it won't be today. I appreciate the help you guys.

 

Here's another schematic that someone else posted here a few years ago, and was used for another Murray predecessor (American Yard Products) which made units for Sears (prefix 917):

It may be helpful; but please note that even within this one representation, the switch shows seven(7) terminals up in the wiring diagram . . . . but then has only six(6) when shown at the bottom of the same chart! So is it any wonder that a Layman might be a little confused when venturing into this arcane aspect of lawn mowers ?

I recognize that the unit portrayed here DOES NOT show the hook-up for your carburetor solenoid; but that has to be considered an accessory which should be powered (open) anytime the ignition switch is ON, and OFF (due to a spring load) when the key is turned to OFF.

I also checked the mower for which I created a wiring harness from scratch, and I see that I wired the Alternator lead WITH the Diode (thus DC) to the Battery Terminal, and that other one w/o Diode (thus AC) to the Lights, and the switch I used only has five(5) terminals !

One consideration is that the carburetor solenoid may require 12V DC, and not the AC because the AC output can vary depending upon engine speed, which may not be sufficient to keep fuel flowing when the engine is only at an idle. My only recommendation is to experiment and remember that this may be an issue.

If this representation is too small, or too confusing . . . . then disregard it. It's only a lawn mower, right; how complicated can it be ?

 

" It's only a lawn mower, right; how complicated can it be ? "

You'd think, but it is more difficult than trying to figure out the wiring or other issues with most of the cars we work on...

 

Ok, so an update...I went with your suggestion here:

G = Ground;
S = Starter Solenoid;
L = Lights;
M = Magneto (kill circuit);
B = Battery (hopefully fused at 10 or 15 Amps with in-line Ammeter?, and any safety switches);
X = Accessories.

This is close to my switch, not exact though.
I put the lights on L, which was also tied to the carb switch. Still no dice. If I put power straight from the battery to the carb, I get it to start and run just dandy. Once it was running I went from ground to each pin on the switch, while in Run, I have no power on anything except the wire coming from the battery which is also tied to the diode line from the stator.

What I am thinking to do is get a low voltage AC, or low current relay and use it for the carb, once the engine spins and the stator generates a little current, close the contact to pull in battery to the carb switch. I know its not on there now, and wasn't before, but, what else to do? If I wire it to a separate switch, then I could forget to turn it off and drain battery. If I hook it directly to battery then its hot all the time and drains battery.

A few things I noticed tonight once it started, we had the contact for the blade engage safety, so the blade was running, and the engine would crank and start with the blade on. The other is the lights, I have to turn the key back to run 1 to get lights. This is exactly what the diagram says, however as I said earlier too, its not a car. I am preprogrammed to having the lights on when I turn the switch on, I expected the lights to be on once the thing started. When I turned the key back to shut it down, I went from Run 2 to Run 1, boom lights on. I'm thinking WTF? Then it clicked....Moved the safety for the blade engage, so that works, and the lights work. All I need is to figure out if there is a way to get the carb switch to work now. Putting it to accessory, which is common with "L" didn't do anything for me.

The old switch had a "Y" terminal on it.

 

On the schematic I uploaded 6/5/17, "L" feeds something called the anti-afterfire solenoid, and keeps it open while the engine is running.

This is your carburetor solenoid, so "L" should keep it OPEN while the ignition key is in Start of Run position:

http://www.briggsandstratton.com/lam...rfire-solenoid

I don't know how "L" relates to that Solenoid; but there it is !

 

Interesting...The mower I have doesn't have this on it, at least I sure didn't see it. That doesn't mean it was never there though.

 

But I thought you mentioned those connectors on your carb bowl (the fuel solenoid) in your 1st post way back on May 12th ?

 

The carb bowl has this on it, but it doesn't look the same as the anti fire solenoid I looked up.

 

They're certainly not all identical in appearance; but here's a group such devices, some of which may look similar to yours:

https://www.google.com/search?q=anti...w=1600&bih=770

Some may refer to it as an anti-backfire solenoids; others as an anti-afterfire valve. The functionality remains the same . . . . to CLOSE down the supply of fuel immediately after the Ignition Switch is moved to Off. I've just called it a fuel solenoid.

Does yours have a visible part number on it ?

If so, look it up by Part Number and see if it isn't as we're attempting to describe it.

 

Actually they both show 7...

Exactly what I hear quite often as they are pushing their basket cases off the trailer into my shop :P

 

The newer ones are longer and skinny but should fit the same hole, you can also bypass the entire thing either with a proper bolt and crush washer, or pull the solenoid out and snip off the needle. If you do the bolt just make sure you don't have power on the wire that goes to it, if you do you can tape it off and secure it. If you snip the needle you can just plug it in and won't matter if it has power or not.

 

Thanks BFH, I'll keep that in mind if I simply get to the point of giving up!

 

That could be for the headlights. Some engines use AC voltage off the stator to run the lights.

 

This wire should also be fused before the ignition switch.

Can you post the wiring diagram you have or a link?

 

Murray, to my Knowledge was never made by AYP/Electrolux and now Husqvarna, and is now owned by Briggs & Stratton.
Technically AYP/Husqvarna produced for Craftsman which is a brand owned by but not exclusive to Sears.

 

You can take the fuel solenoid out and clip the plunger off of it and then you won't need to power it to make the engine run. It may or may not backfire when you shut it off though. Usually if you bring it down to idle and let it run for 10 seconds or so before shutting it off, it will not backfire.

 

Yes, the Ownership and Organizational history of that segment of the business is very convoluted.

I have an 1973 AMF Machine, and when I need parts, I use the same part numbers to search under all of the companies who've manufactured that line of units ranging from AMF, Dynamark, Turfmaster, AYP, Noma, and then Murray.

Now that B&S owns Murray and all of its predecessors, maybe there'll be some stability . . . . or the next operation will be in China.

 

The diagram I'm working from. It isn't exact, but its a good reference. My last issue is to figure out how to make the fuel anti backfire solenoid work without defeating it. Although the hood fell off and broke the other day...
Disregard the carb drawing on there, that was before I got this far and found out there's no 12V except directly to battery.
I'm thinking low voltage AC relay that would get power from the AC output of the stator, once the engine starts to crank it would generate enough voltage to pull in a 6VAC relay that would control the 12VDC to the solenoid. Having a tough time coming up with that relay though, basically an automotive relay, except 6VAC.

 

You have 12VDC available from the Charging Circuit; can't you use that to power the fuel solenoid from the "ON" position of the switch ?

When you turn the switch off, the fuel solenoid will close,

 

I metered through the switch. There is no "key on" 12V source with the engine off. If there was that is where I would put this. That's why I'm having a tough time trying to find out how to do it.

 

But you don't need (or want) the Fuel Solenoid to be open while the engine is "Off"; only when it's supposed to be running.

 

Right, but I need a key on 12V to fire the solenoid before the engine starts.
The only time I have 12V on the lugs of the ignition switch is when the engine is cranking, it triggers the solenoid. Otherwise the switch is dead, besides VBatt terminal B. I can't hook the fuel solenoid to B, then it is hot/on all the time.

 

It sounds like the original switch for that machine was equipped with a 12 Volt DC lead in the "On" Position and the "Start" Position, and the Switch you're trying to use just doesn't have one. Perhaps that was the mysterious 7th (seventh) terminal ?

 

Not sure, I never saw the original switch.
When we got it, my GF used it for her yard, I never used it.
I'm not sure if it charged or how it really worked.
This year I am trying to get it going again since something crapped out during winter.
When I looked at the hack job of wiring, I pulled it all apart, and here I am now...

For all I know the solenoid could have been connected directly to battery terminal on the switch.

 

If you can't find the correct Ignition Switch, then you might consider doing that again, with a simple in-line toggle switch to open and close the fuel supply.

 

I would get another switch, the one you have is not correct.

 

So, an update on progress...
I had the right switch, and the right parts, just the wrong drawing.
When I got the info about the after fire solenoid, I was looking through the wiring diagrams provided by Murray and found on that fit the tractor I have, mainly the after fire solenoid.
Put everything together as shown on that wiring and it fires up and runs good.

Now I just need the new headlight bezel, or whatever that part is called and this one will be good to go.

Thanks for all the help with this, it was painful. Having the right diagram really made it easy, but getting there, not so much.