Defective ignition switch?

[bertsmobile1]

Just note here the starter solenoid used is a relay (contactor). Just depends industry you familiar with.

It appears that you don't understand the kill circuit operation. In the yellow path. The brake switch must be open (Switch depressed), The PTO will be in open position in disengaged position. The seat switch must be open (switch depressed or operator on seat). Note: The parts list does it being wired the same as the brake/clutch switch which is incorrect. It contact positions is drawn backwards. The seat switch is common to both the brake switch and PTO circuit magneto kill circuit.

Anyways what you are describing is defective ignition switches or the you have the wrong ones. Are you trying to after market or oem switches? It should never ground the magneto in start position. I do know that Oregon 33-383 is the same switch as the Murray 92556 (superseded to Briggs 092556MA). I have tested the in house new Oregon switch here and it does not short out the magneto in start position.

There are some Toros ( I think ) that use a common relay for cranking and for killing which is why I asked about a relay .
I had a similar fault because this relay had failed and it caught me out because both trigger connections were used and they switched functions once the cranking stopped.

 

[tkos115]

So just an update, I was able to finally fix the issue with this mower. It turned out to be an ignition switch issue. After putting the 4th switch in it, the problem went away and it has been working fine. The first brand I went with for the first two switches was Stens, then the last two I went with the Briggs made 092556MA. All the switches were looked up and were listed as a replacement for the 092556MA part number. I have never had such bad luck with defective parts like this but im glad it's finally done..

 

[StarTech]

I wouldn't think I have problem with Briggs OEM fuel solenoids either but I had 6 in a row that would not retract; unless, they were bumped.

So yes there can be batches of defective items.

 

[bertsmobile1]

So just an update, I was able to finally fix the issue with this mower. It turned out to be an ignition switch issue. After putting the 4th switch in it, the problem went away and it has been working fine. The first brand I went with for the first two switches was Stens, then the last two I went with the Briggs made 092556MA. All the switches were looked up and were listed as a replacement for the 092556MA part number. I have never had such bad luck with defective parts like this but im glad it's finally done..

This is exactly why I kept on recommending using patch cords to bypass switches and if necessary bypass wiring between switches .
Stens stand by their products when bought from an authorised dealer and down here have always been very grateful when I found a defective product so send the duff ones back for a refund.

Glad you got it beaten feel good dosen't it.

 

[ShaneZampire]

I thought I would share since this page is now the top result when you google this problem. Maybe others will chime in and we can all help each other.

I have 5 Murray wide body mowers. All around 2000-ish models. 4 are in great working condition. I just like them so I pick them up when I find a good deal and restore them. All have the 7 terminal ignition switches. I am sure some have been replaced over the years with OEM and aftermarket but, they all work as they should and as intended.

So 4 weeks ago I picked up my 5th one. Was ok for a two decade old mower but needed paint, and a going through. I asked the guy what all was wrong with it and he said the biggest problem was you had to hold the key in the start position for like 30 seconds, then let off and it would start. He said he replaced the solenoid, plugs, new carb, key switch last season, and it didn't change a thing so he just lived with it. He said had to be the coil. So 3 weeks ago as I was going through it, checking all wires, switches, diodes, etc. I had the spark plugs out and noticed they only fired once I let off the key switch and motor was winding down. o0 So I took the switch and checked it out. Sure enough, it was grounding out to "M" in the start position. I knew he said it was doing same thing before he put on a new switch last year. What is the odds? So I checked and double checked ignition switch part numbers, wiring diagram, and ignition switch position contacts. All was correct other than the ignition switch was making an extra contact it should not be which is engine kill and engine start at same time.

So I order another aftermarket switch off Amazon. Two days later it arrives and I just throw it on. Same thing! No way! Check the switch and it is same way. I immediately come in, request a refund, and order another brand. Two days later I receive that switch. Same thing, Start makes contact with B+L+S M+G I walk into the house, request a refund and order a Stens switch. 3 days later I receive another defective switch. I am now on my 4th switch and will be ordering an Oregon 33-383 I seen someone here mention. If this one is defective, I guess I will track down some NOS OEM switches. But when they say its a direct replacement for Murray - 92556, Murray - 092556MA, either they are just flat out wrong or we have a mass batch of defective switches.

I have been reading and researching this for 3 weeks now and this problem goes back years from looking at the dates on some the reviews and posts. And its not just one brand. They all messed up or there is just one company making the same switch and just labeling it who's ever brand.

Below is the ignition switch contacts and wiring for the 92556 switch and also a few random reviews from different brand switches that are "suppose to be" exact replacements for the common standard 7 terminal Murray and other mowers of the 2000 era.

 

[bertsmobile1]

IS the connections B+L+S+M according to the letters on the back of the switch or the actual wires in the plug ?
If that was the actual switching then it is putting voltage onto the magneto and that will kill the trigger chip the very second that contact is made thus destroying it

 

[ShaneZampire]

bertsmobile1:​

It's actually B+L+S AND M+G terminals making contact in the start position. Its almost like the switches are in the start position and off position at the same time other than the "L" does not make contact with M+G in the "Start" position as it does in the "Off" position. The terminals are lettered on the actual switch just as in the picture above.

I got side tracked on another project so this one got put off for a little while. Right after the above post, I did have another switch come in I had ordered off eBay I forgot about. It is the same way. No brand. It just came in a little white box. So I now have 3 defective switches on hand and the 5th I have tried and tested bad.

Also shortly after the above post, I had plans of trying the Oregon one and Tractor Supply has a MTD 7 terminal one in stock. I was going to ask the manager could I test it right there in the store. I got around to neither. I did find a NOS one on eBay for the same price as all the others so I ordered it as an intended spare. It just came in about 2 hours ago. I just tested, double, and triple tested it. In the "Off" position, only M+G+L make contact and in "Start" position, only B+L+S make contact. Below is the exact one that I just now received.

 

[bertsmobile1]

Does not make sense to have a switch with B+L+S & M+G at the same time unless the mower uses a NC relay on the magneto kill wire.
M+G+L uses the alternator as a brake to stop the engine faster .
As you have worked out by now there are a lot of variations and the number of terminals alone is not a good enough description of a switch.
Down stairs I have at least 2 different 7 pin switches .
The box of good used switches has at least 20 different switches , many of which will plug in but not work on a particular mower.
The other sneaky problem is the Ground wire to the switch is often just screwed into the dash and quite a bad ground .

 

[ShaneZampire]

As you have worked out by now there are a lot of variations and the number of terminals alone is not a good enough description of a switch.
Down stairs I have at least 2 different 7 pin switches .

Yea, the MTD one at Tractor Supply has no mention of replacement for 92556, 092556MA. I was just hoping it would make the correct contacts I needed and was looking for. It just says "MTD OEM-725-1717 Ignition Switch. Simple to install, the riding mower ignition switch fits garden tractors made in 2002 and prior." All the others I had bought, tried, and tested actually said 92556, 092556MA replacement which they were not or all defective. Also to note is the 7 terminals are arranged like a Christmas tree. 1 then 2 then 3 on bottom row. (6 terminals) Then the 7th (ground) is off to the side and just a wire with a space connector slides onto that terminal. The plastic molded wire plug will only fit the correct arranged terminals.

Also Update: I installed the NOS OEM one today. Turned the key and it fired right up after about turning over 3-5 times. It was nice not having to wind the motor for a few seconds, let off, and hope this is the time it starts. This one has the 19.5hp B&S Twin engine so the fuel pump is steady pumping gas into the carb. when turning over. With the defective switches, you better wind it up just right and let off or you was for sure going to flood the crap out of it.

If time allows and I don't forget, I want to take one of these defective (or switches purposely made to make extra contacts) apart and just see what's going on inside. Take some pictures and share. When I Googled this problem, this thread was the #1 result. It helped me. I know there are others out there from the 3 weeks of poking around, reading so many reviews, other forums, and other places with people the same problem.

 

[ShaneZampire]

So I took the switch apart. Here is what I think I see. The contacts are around the outer edge like numbers on a clock. The contact wipers are fan shaped. The inside (center) of the each wiper has a little nipple that can make contact with G or L because them two contacts have copper traces that run inside to the center. The outside is wide enough to catch 2 contacts at a time. Each wiper is 180 of each other (straight across from one another). Each wiper has a spring that presses them down onto the contacts to keep pressure on them. Each wiper's outer wide side is curled up (so it slides smoothly across the contacts)

So when the key is in the "Start" position, one wiper, the outer fan is on B+S and the inside of the wiper is on L. Now the other wiper ... It is almost centered directly over the G contact but little to the M side. It is offset enough that with the spring pressure, with the inside teetering on the inside nipple, and the wide fan part on the raised G contact, it will tilt onto and make contact with the M. It looks like the designers actually put two raised places on the board on each side of the G contact to prevent this maybe?. But this switch I took apart, the raised part between the G and M is not high enough. It looks like it was a tad higher, and with the ends of the wipers curled a little, it may would not make contact.