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I bought a used murry with a 42" deck, Briggs and Stratton 16.5 HP (engine model 28W707) and the PO did a hack wiring job. So I'm trying to find a wiring diagram, but the sticker on the mower is half way wore off. I hope these picture attachments works. Does any one have an ideal of the model or know of a way i can find out? Thank you.

First a little computer magic
Go back and drag the mower out into the sunlight.
Take some photos of tag at the highest resolution you camera has ( camera is better than a phone ) at different angles.
Go inside and upload the images then play around with the contrast also try inverting the colours as well.
Digital cameras are a lot more sensitive to dirty white on dirty white than your eyes,
The area under where the type was will be less faded than the areas without the type so will be closer to the original colour.

Next , most Murrays are wired according to the std Briggs wiring diagrams.
The wiring schmatics were done by a keyboard jockey with absolutely no idea of what he was doing
But they should be good enough for you to blunder through with.

Later models will have what passes for a wiring diagram will be found in the owners manuals that have a parts section in the back.
Below are a couple from Murray books and the general Briggs wiring diagram

This is a diatribe from some previous answers to people with wiring / stating problems.
Before you do any wiring repairs , remove the blower housing and remove the kill wire form the magneto.
After you have finished check this wire for voltage with every combination of the controls.
If it even thinks it is going to get battery or alternator voltage then control chip in the coil will self destruct and those little buggers are not cheap.

Behind the ignition switch are tiny letters nd they code out like this

B = battery voltage always active
S= Start, gets 12 V when turned to the start position
A = Alternator gets connected to B so the battery can be recharged
L = Lights may be a 12 V teminal with DC lights or ground for AC lights.
M = Magneto should be either open circuit or ground when turned off
G = Ground.

There might be A1 & A2 or L1 & L2 and these just split circuits for things like hour meters , accessory power outlets , hour meters & grounding the alternator to effectively make it a brake when the engine is shut down.

The PTO & brake switches are usually double switches.
One side is live and used for cranking and the other side is ground, used for safety switching.
The switches connect the terminal flat side to flat side ( orange to orange or yellow to yellow )
The PTO & BRAKE switches will have one side connected pin in & the other side disconnected pin in and these reverse when the pin is out.
If you have to replace them make sure the new switches work the same way as JD use an identical looking switch where the contacts are reversed.

The start circuit is a loop,
Fuse > B terminal >S terminal > PTO Switch > brake Switch > solenoid trigger > ground.

View attachment Murray wiring -1.pdfView attachment wiring -2.pdf

can you post some pictures of your ENTIRE mower .. I have a bunch of Murray info. maybe I can help ..??



OR ....... you can go through these manuals trying to match up ......

https://www.ereplacementparts.com/murray-lawn-tractor-parts-c-17887_17888.html
go down to where the numbers start with 42 and check them out ...

Thank you guys for your help. I do not have a better camera, but I'll take some more pictures of it tonight. When i get home tonight I'll look at the back of the ignition and see if its coded at all.

I do have a picture of the wiring that I need a diagram for. There is a red yellow and white that comes from the ignition, black and red that comes from the stator, a gray wire that comes from the bottom of the carburetor and a black wire that comes from the coil.

Your enginge code number shows it to be a FEBRUARY 1999 model, ( if the shroud hasn't been changed ) so IF the engine is ORIGINAL to the mower it should be a 1999 OR a 1998, check your ignition switch to see how many terminals it has, ???

The gray wire in your right hand, should go to a connector on the carb. solenoid (bottom of carb.) the black wire in your right hand, MIGHT ... ( should) go to the coil, if so, its the "kill" wire, the RED & BLACK coming down from under flywheel are your stator wires, there should be a diode in one of them, (the RED I believe) I think I have some pics of the elect connectors in my files, .... I'll have to check.....

Boobala said:

Your enginge code number shows it to be a FEBRUARY 1999 model, ( if the shroud hasn't been changed ) so IF the engine is ORIGINAL to the mower it should be a 1999 OR a 1998, check your ignition switch to see how many terminals it has, ???

The gray wire in your right hand, should go to a connector on the carb. solenoid (bottom of carb.) the black wire in your right hand, MIGHT ... ( should) go to the coil, if so, its the "kill" wire, the RED & BLACK coming down from under flywheel are your stator wires, there should be a diode in one of them, (the RED I believe) I think I have some pics of the elect connectors in my files, .... I'll have to check.....

Click to expand...

Thank you for that info.

The gray wire is connected to the carb, the black wire is connected to the coil, i just need to figure out where they go from there. I'll look for a diagram and FSM tonight.

You need to remove the ignition switch with it's connector and take a pic of the wiring in the conn. there are several wiring variations on the Murray mowers, some have 5, 6, & 7 terminals depending on the engine, and components, of the various models, without the model number of the mower, it's a lengthy process, have you had this machine running ?? you actually only need 2 wires to "hot-wire" the engine to test it with jumping the starter, most of the wiring is the safety switches. IF you plan on keeping the machine, I would suggest you get the wiring harness either new or used, ... spliced wires and "jury-rigging" usually causes problems later. still looking for those pics I have.............

Found these pics (finally) anyway these are from my former mower, this particular model used a 7 terminal ignition switch, see enclosed diagram, I hope these pics and the diagram don't lead to confusion on your part (NOT my intent) ... just trying to give you an idea of how different models are wired, The VIOLET & BLACK wires are for the headlights, the YELLOW & ORANGE are the safety switch circuit,NOW without seeing or knowing the model number of the mower or the terminals on the IGN. sw. I'm only guessing, .... need info of your IGN. sw. and it's wires.......

View attachment 37571..View attachment 37572..View attachment 37573..View attachment 37574..

Yes it was running, but i was getting intermittent spark, which lead me into the wiring. The PO did a garbage job trying fix the wiring. So now i wanna fix it correctly.

I'll dig into more when i get home tonight. I was only able to see one of your pics, the one of the carb. Your carb is different then mine. Yours appears to have screws hold the bowl on while my bowl just twists onto the carb.

06compound said:

Yes it was running, but i was getting intermittent spark, which lead me into the wiring. The PO did a garbage job trying fix the wiring. So now i wanna fix it correctly.

I'll dig into more when i get home tonight. I was only able to see one of your pics, the one of the carb. Your carb is different then mine. Yours appears to have screws hold the bowl on while my bowl just twists onto the carb.

Click to expand...

......

I hope you can see these pics I reloaded them ..... NEED PICS OF YOUR SWITCH !!!...

Those pics worked, thank you. I just got off work, so I'm gonna go get those pics

Sorry the one pic is bad, i labeled the prongs that have letters on them. Starting at the bottom going counter clockwise it's M,B,S,A,Y. The far left prong had a single black wire going to it and the rest were in a pigtail. The bottom left prong to the left of the M has 2 yellow wires going into it, those are in the pigtail along with M,B,S,A,Y.

The one all by itself and turned sideways should be the G = Ground terminal.
Confirm this by checking continuity, it should not have any in all positions other than off when it will be connected to the M = magneto terminal to ground the mag.
The other wire will be an A or L terminal
So you have a 7 terminal ignition switch, that is a good start.
On some wiring the G terminal is not part of the plug and has it's own wire.

That single black wire is a ground.

06compound said:

That single black wire is a ground.

Click to expand...

Where is the BLACK wire connected as a ground .... does it go to the coil ..??

Do you have the connector from the key-switch..?? a picture of it ON the switch wwith the wires ( if you have any left) would be VERY VERY helpful, do you have the connector on the carb solenoid..if so .. what color wire is NEXT to the GRAY wire and is it connected anywhere ..??

I'm NOT there .... YOU are my eyes ...... I can only help YOU ... if YOU help ME !!

can you understand the wiring diagram I posted..??

OK did some digging, I'm confused about the M terminal, .. & the one next to it with the YELLOW wires, I think you may have those 2 confused ...... you will have to check closely, the YELLOWS should be on the M terminal......check out these pics & DIAGRAM, ... THIS ... SHOULD be the diagram for your mower as I asked before .. do you know how to read the diagram .??? also examine these pics CAREFULLY, ...... NOTE THE LETTERS ON THE BACK OF THE SWITCH !! ARE THEY THE SAME AS YOURS EXACTLY ??? From what I see, the bottom CENTER terminal should be the "L" terminal ..!!! and "M" should be NEXT to the "G" terminal.

IF so .... THEN this is the diagram to use ... it's used on the 40, 42, & 46 inch deck machines ( see bottom of diagram ) KEEP me up dated...........

....

AM I clear on all this with you ..????

Boobala said:

OK did some digging, I'm confused about the M terminal, .. & the one next to it with the YELLOW wires, I think you may have those 2 confused ...... you will have to check closely, the YELLOWS should be on the M terminal......check out these pics & DIAGRAM, ... THIS ... SHOULD be the diagram for your mower as I asked before .. do you know how to read the diagram .??? also examine these pics CAREFULLY, ...... NOTE THE LETTERS ON THE BACK OF THE SWITCH !! ARE THEY THE SAME AS YOURS EXACTLY ??? From what I see, the bottom CENTER terminal should be the "L" terminal ..!!! and "M" should be NEXT to the "G" terminal.

IF so .... THEN this is the diagram to use ... it's used on the 40, 42, & 46 inch deck machines ( see bottom of diagram ) KEEP me up dated...........

View attachment 37592..View attachment 37593..View attachment 37594

AM I clear on all this with you ..????

Click to expand...

Only problem with that Boo is there is no guarantee that the switch he has is the one that came with the mower.
Most of the mangled wiring I find. originated from trying to fit the wrong ignition switch.
Even seen car switches used several times.
Must have all been done by the same dipstick as they all used a N/C relay to ground the magneto to turn the thing off.

The wiring diagram ( if you can call it that ) which you supplied is the export one with single pole safety switches.
I would think he has double pole safety switches with the extra magneto kill wires

Boobala said:

Where is the BLACK wire connected as a ground .... does it go to the coil ..??

Do you have the connector from the key-switch..?? a picture of it ON the switch wwith the wires ( if you have any left) would be VERY VERY helpful, do you have the connector on the carb solenoid..if so .. what color wire is NEXT to the GRAY wire and is it connected anywhere ..??

I'm NOT there .... YOU are my eyes ...... I can only help YOU ... if YOU help ME !!

can you understand the wiring diagram I posted..??

Click to expand...

I lied, there are 2 black wires. One is grounded next to the starter solenoid by the steering wheel shaft and the other runs up to the headlights. The gray wire connected to the carb runs into a pigtail with the black wire from the coil.

Boobala said:

OK did some digging, I'm confused about the M terminal, .. & the one next to it with the YELLOW wires, I think you may have those 2 confused ...... you will have to check closely, the YELLOWS should be on the M terminal......check out these pics & DIAGRAM, ... THIS ... SHOULD be the diagram for your mower as I asked before .. do you know how to read the diagram .??? also examine these pics CAREFULLY, ...... NOTE THE LETTERS ON THE BACK OF THE SWITCH !! ARE THEY THE SAME AS YOURS EXACTLY ??? From what I see, the bottom CENTER terminal should be the "L" terminal ..!!! and "M" should be NEXT to the "G" terminal.

IF so .... THEN this is the diagram to use ... it's used on the 40, 42, & 46 inch deck machines ( see bottom of diagram ) KEEP me up dated...........

View attachment 37592..View attachment 37593..View attachment 37594

AM I clear on all this with you ..????

Click to expand...

I look at my switch a little harder with better light and i see other letters now. It matches the one in the picture you posted. So the 2 yellow wires are going into the bottom left (per my pic) M terminal. Then to the right of that is the L terminal.

I'll be able to get it all wired back together with the info/diagrams you gave me, much appreciated.

Just heed the warning about power on those yellow wires.
leave the coil kill wires off till you have wired the mower, started it and tested for voltage on the yellow wires at the coil

Ok, thanks for the heads up. My new coil should be here tomorrow and I'll update after i get it installed and everything.

bertsmobile1 said:

Just heed the warning about power on those yellow wires.
leave the coil kill wires off till you have wired the mower, started it and tested for voltage on the yellow wires at the coil

Click to expand...

I got it fired up and i got 0 volts on the yellow wire that connects to the coil. So I'm guessing that's what i want?

06compound said:

I got it fired up and i got 0 volts on the yellow wire that connects to the coil. So I'm guessing that's what i want?

Click to expand...

BETTER NOT have voltage on the coil "KILL" wire it's a ground wire that when hit with voltage will fry the coil .

so what about everything else..?? You're good to go ..??

That's what i was thinking about the kill wire. Everything else is good, just gotta connect all the wires. I appreciate the help very much.

So now i lose spark once i hook up the kill wire to the coil. Looking over the diagram, the discrepancy i see is terminal L. There is only red wire on terminal L. The diagram shows a gray wire thats supposed to be in there as well that runs to the solenoid in the carb.

06compound said:

So now i lose spark once i hook up the kill wire to the coil. Looking over the diagram, the discrepancy i see is terminal L. There is only red wire on terminal L. The diagram shows a gray wire thats supposed to be in there as well that runs to the solenoid in the carb.

Click to expand...

Without the wire harness and connectors it makes the job tough..... what color wires WERE on the carb solenoid .. GRAY & YELLOW ..?? in the diagram, the gray is "shared" with the RED which is getting power from the DC out of the stator, the YELLOW wire on the solenoid, is the GROUND wire which goes back to terminal M on the IGN. sw. which goes to the safety inter lock switches ....... do you have those still on the machine and connected, I CANNOT see what you have there and as I said without the connectors it's a headache, go look at the pictures I sent and see how the wires are looped in the connectors.
you should have 4 (four) wires coming FROM the engine, a RED & BLACK (from the stator) and a GRAY & YELLOW from the solenoid these go to 2 (two) small connectors which in turn go to the main harness, which connects to the ign. sw. if the safety switches are hooked up (and working) you MUST be sitting in the seat, blades DIS-ENGAGED, and trans in NEUTRAL with CLUTCH pedal pressed down, JUST BE SURE THAT WHICH EVER WIRE YOU HOOK TO THE COIL, .. DOES NOT HAVE VOLTAGE WHEN THE KEY IS IN THE ON POSITION !!!!! AS I stated earlier if you plan to keep the machine I would buy the wire harness's and end your nightmare ! It's NOT worth the aggravation and problems later . also : some Murrays used different color wires and some were wired a bit differently, without your exact model number, we're shootin in the dark, might have to check out a different harness set-up, and start over. .. ??

Here's another diagram, actually wired the same but you might be able to read this one better, you'll have to convert the numbers to the letters, no problem ..Right ?? Are we having fun or what ..?? ( LOL ) ... :confused2:..:confused2:..:confused2:


......... click once to enlarge, THEN click again ( bigger still )

Boobala said:

Without the wire harness and connectors it makes the job tough..... what color wires WERE on the carb solenoid .. GRAY & YELLOW ..?? in the diagram, the gray is "shared" with the RED which is getting power from the DC out of the stator, the YELLOW wire on the solenoid, is the GROUND wire which goes back to terminal M on the IGN. sw. which goes to the safety inter lock switches ....... do you have those still on the machine and connected, I CANNOT see what you have there and as I said without the connectors it's a headache, go look at the pictures I sent and see how the wires are looped in the connectors.
you should have 4 (four) wires coming FROM the engine, a RED & BLACK (from the stator) and a GRAY & YELLOW from the solenoid these go to 2 (two) small connectors which in turn go to the main harness, which connects to the ign. sw. if the safety switches are hooked up (and working) you MUST be sitting in the seat, blades DIS-ENGAGED, and trans in NEUTRAL with CLUTCH pedal pressed down, JUST BE SURE THAT WHICH EVER WIRE YOU HOOK TO THE COIL, .. DOES NOT HAVE VOLTAGE WHEN THE KEY IS IN THE ON POSITION !!!!! AS I stated earlier if you plan to keep the machine I would buy the wire harness's and end your nightmare ! It's NOT worth the aggravation and problems later . also : some Murrays used different color wires and some were wired a bit differently, without your exact model number, we're shootin in the dark, might have to check out a different harness set-up, and start over. .. ??

Click to expand...

The gray wire from the carb is connected to the red wire that comes off terminal L on the switch. The gray wire is looped into the terminal L red wire like in the picture you showed me.

So from what you've said it sounds like the coil is supposed to ground out the coil killing the spark? If that's the case, then it seems to be working backwards.

All the wiring is correct per the diagram.

I might have to get another harness, but i enjoy working on things like this and learning.

For now I'll wire a toggle switch into the coil kill wire to shut off the engine.

Boobala said:

Here's another diagram, actually wired the same but you might be able to read this one better, you'll have to convert the numbers to the letters, no problem ..Right ?? Are we having fun or what ..?? ( LOL ) ... :confused2:..:confused2:..:confused2:


View attachment 37636 ......... click once to enlarge, THEN click again ( bigger still )

Click to expand...

nope, not confused lol. I can read and understand this diagram and the first one.

A DAMN good thing you have BOTH, patience & persistance .. :thumbsup: .. :laughing:..:laughing:

actually the coil is also grounded out by the safety switches .. seat empty, blades engaged and trans in gear that's why we warned you about being sure there is no voltage on a yellow going to the coil .

I just doubled checked there no voltage on that wire. Sitting on the seat, blades engaged and trans in forward motion. Volts dropped down to -.5XX

06compound said:

I just doubled checked there no voltage on that wire. Sitting on the seat, blades engaged and trans in forward motion. Volts dropped down to -.5XX

Click to expand...

NO, NO, NO, ......... in the seat, blades OFF, OUT of gear, foot ON clutch to START ! just curious, was there much left of the original harness's ..??

AND I guess all your safety switches are working ..??

Yes there was enough of the original harness, but last night i stated rewiring it. The battery is not charging, lights aren't getting power and i found a few chafed wires.

I found 2 safety switches that were all wrapped up in tape. They look to be the PTO and clutch brake switch according to the diagram. But the diagram shows 1 orange wire running through those switch and there is more then one wire ruining through them. They both have 2 orange wires (in and out I'm guessing), one switch has 2 yellow wires and the other switch has 3 or 4 yellow wires, i can't remember off the top of my head. I'll have to see where those yellow wires run to.

06compound said:

Yes there was enough of the original harness, but last night i stated rewiring it. The battery is not charging, lights aren't getting power and i found a few chafed wires.

I found 2 safety switches that were all wrapped up in tape. They look to be the PTO and clutch brake switch according to the diagram. But the diagram shows 1 orange wire running through those switch and there is more then one wire ruining through them. They both have 2 orange wires (in and out I'm guessing), one switch has 2 yellow wires and the other switch has 3 or 4 yellow wires, i can't remember off the top of my head. I'll have to see where those yellow wires run to.

Click to expand...

When I was in the A.F. I did quite a bit of rewiring on certain components, after I got out I was still in aviation, again rewiring components, and the MAIN wire harness's used ALL one color wire WHITE ! ... good thing we had "stick-on - numbers" even with that, it was a tedious task to do.
and usually the sub-components had color wires but after you build 10 or more, the next 50 aren't so bad ..:confused2:

I'm in the infantry, so i dont need to know that smart stuff haha.

I ordered a new stator today, some of the coils on it looked burned.

When i removed the flywheel bolt, i found a flywheel key in the bolt hole. After going over this thing, i just dont understand some people way of fixing things, it looks like garbage. Some people shouldn't be aloud to work on things.

06compound said:

I'm in the infantry, so i dont need to know that smart stuff haha.

I ordered a new stator today, some of the coils on it looked burned.

When i removed the flywheel bolt, i found a flywheel key in the bolt hole. After going over this thing, i just dont understand some people way of fixing things, it looks like garbage. Some people shouldn't be aloud to work on things.

Click to expand...

AMEN !!

06compound said:

Yes there was enough of the original harness, but last night i stated rewiring it. The battery is not charging, lights aren't getting power and i found a few chafed wires.

I found 2 safety switches that were all wrapped up in tape. They look to be the PTO and clutch brake switch according to the diagram. But the diagram shows 1 orange wire running through those switch and there is more then one wire ruining through them. They both have 2 orange wires (in and out I'm guessing), one switch has 2 yellow wires and the other switch has 3 or 4 yellow wires, i can't remember off the top of my head. I'll have to see where those yellow wires run to.

Click to expand...

Go back to the beginning to the wiring diagrams I posted.
You will see that in those diagrams the Brake & PTO switch both have 4 wires.
The yellow wires should be the magneto kill wires and the orange ones are the cranking circuit.

bertsmobile1 said:

Go back to the beginning to the wiring diagrams I posted.
You will see that in those diagrams the Brake & PTO switch both have 4 wires.
The yellow wires should be the magneto kill wires and the orange ones are the cranking circuit.

Click to expand...

Thank you, i had a different diagram i was looking at.

So I rewired it and its working so far. The engine will die now when i turn the key off. I would like to check that the battery is charging, but I'm not sure what wire to check. So which write do i check to see that the battery is getting a charge?

Connect a VOLTmeter across the battery terminals while the engine is running, should have 12V. or better at idle and about 12.9 or higher at FULL throttle.

I tried that, but i already had 12.xx volts from battery worth the engine off. I fired up the mower to see if there was a change in voltage, but there was like a .3 drop in voltage with the engine running.

THIS may be of help......

http://www.promotor.fi/galleria/alternator_replacement.pdf

https://www.youtube.com/watch?v=9N9EISHD24w

Well i mowed for a few hours and the battery never died. Last time i mowed for a few hours the battery died, so i think it's charging.

Was any of the electrical info. I sent of any help to ya ... ??? ..

Boobala said:

Was any of the electrical info. I sent of any help to ya ... ??? ..

Click to expand...

I've been busy and haven't had time to look at it yet.