Defective ignition switch?

[tkos115]

Well, to try and make a long story a little shorter I have a Murray riding mower from 2003. It has a Briggs and Stratton engine on it. Water got into the original switch and caused it to lock up. I put a new ignition switch in it but I never got around to testing it because the battery was dead and it was at a family members house. So it sat under a tarp for about 3 months until they decided they wanted me to fix it up. The problem I'm having is when I crank it, it cranks over fine but I don't get a spark until I let off the crank position and the spark comes back and it will fire. Everything else works fine, lights, charging system, safety switches etc. Now when I unplug a separate prong from that back of the switch that has 2 black wires crimped into 1 pin it will get a spark when cranking and run fine. If I keep this prong unplugged and turn it off it will sputter and spit then die out. (Like the coil isn't getting a good ground to kill the spark). The lights and charging system still work fine when that prong is unplugged. From what I can see for those two black wires on the prong are that one wire goes to the lights, and the other is just a ground that goes to the body.

When I do a continuity test with one test lead on the battery ground, and the other on the backside of the prong that goes to the ignition coil I get these readings..

Key in off position: 0.2 ohms (Normal ground reading)
Key in run position: 1.2ohms
Key in run position with lights on: 1.2ohms
Key in crank position: 0.7ohms
Separate prong unplugged in crank position: 1.2ohms

Does this sound like it's a defective switch that I got? It is a 7 prong switch. Proir to this, I don't believe there were any starting issues like this, but it sat for quiet awhile and wasn't used much.



I would attach some pics but no matter what I do it keeps saying the file size is too large. 1.5mb?


Below is the link to the parts lookup with all the mower info and wiring harness diagram.

PartsTree - Home of OEM Parts for Outdoor Power Equipment

Parts lookup and repair parts diagrams for outdoor equipment like Toro mowers, Cub Cadet tractors, Husqvarna chainsaws, Echo trimmers, Briggs engines, etc.

www.partstree.com

Thanks for your time and help all!

 

[bertsmobile1]

Basically you got the wrong switch
On top of that you are suffering the calculator disease reading numbers that are most likely wrong and thinking they mean something
Pull the plug and the switch out.
On the back of the switch will be letters like shown here
Usually B G M S A L but may be others
They mean exactly what you think
Battery Ground Magneto Start Alternator Lights
B + S = Cranks
M + G = Stops
B + A = recharges & powers carb solenoid
Work out which wires go where
Get a thin screwdriver or grind down a .040" feeler to depress the barbs so you can pull the terminals out of the plug
hook them direct to the switch where you think they should go
Remove the kill wire from the coil and hook up a meter, test light whatever floats our boat to check that it never gets voltage at any key position
Hook the kill wire up & fire up the engine.
Once happy put the terminals back into the plug and refit the switch.
On some switches with metal bodies that go into metal on the mower the ground wire is not ground to the switch but takes ground from the switch body .
Cant be any more specific without knowing model number of the mower so we can look up the schematic and the actual switch make & number.

 

[Richie F]

Does this sound like it's a defective switch that I got? It is a 7 prong switch. Proir to this, I don't believe there were any starting issues like this, but it sat for quiet awhile and wasn't used much.

The wiring diagram in the parts break down is 5 pin.
Why did you buy a 7 pin switch ?
Or do you mean the original switch is a 7 pin ?

PartsTree - Home of OEM Parts for Outdoor Power Equipment

Parts lookup and repair parts diagrams for outdoor equipment like Toro mowers, Cub Cadet tractors, Husqvarna chainsaws, Echo trimmers, Briggs engines, etc.

www.partstree.com

 

[tkos115]

The part number listed seems to goto a 7 pin switch which is what was in it and what I got as a replacement. Might just be a generic picture on the site.

 

[StarTech]

Hope the OP has the right model number linked.

Richie better yourself a new pair of glasses. Even poor diagram shows 7 terminals. but here is a clearer diagram.


IPL say it is PN 092556 superseding to 092556MA.

Pin Out

Make and Break

PIN 7 = B. Battery
PIN 6 = G. Ground
PIN 5 = S. Starter
PIN 4 = M. Magneto
PIN 3 = AC from alternator for lighting. Probably A
PIN 2 = L. DC from alternator Also powers after fire solenoid when switch is run and start position when engine not running.
PIN 1 = Lights. Probably Y
PIN 1 and 3 is A and Y and can be connected either way.

Now if the engine is sputtering to stop the with G disconnected the alternator may not be working and you are just shutting using the after fire solenoid.

 

[Richie F]

You're correct Star Tech time for better eyeballs. Lol.

 

[Fish]

better eyeballs

bigger too!

 

[StarTech]

Heck I having to wear two pairs at the same time now myself. Eye Doctor cant get the prescriptions right. Made a pair for seeing up close but no where near right, instead I need a pair +125 over my regular -350 glasses to see the computer screen clearly. So I can understand somewhat vision problems. Just got remember the separator tube must be working too.

 

[tkos115]

Thanks for your input everyone, I'll be going through doing some more testing in the next day or two now that I have more info. I'm fairly certain that it's a bad switch but I want to make sure before I throw parts at it.

It sounds like since I'm getting a ground to the coil when it's in the crank position there is a switch issue. I couldn't find any pinched or bare wires anywhere.

 

[slomo]

Basically you got the wrong switch
On top of that you are suffering the calculator disease reading numbers that are most likely wrong and thinking they mean something
Pull the plug and the switch out.
On the back of the switch will be letters like shown here
Usually B G M S A L but may be others
They mean exactly what you think
Battery Ground Magneto Start Alternator Lights
B + S = Cranks
M + G = Stops
B + A = recharges & powers carb solenoid
Work out which wires go where
Get a thin screwdriver or grind down a .040" feeler to depress the barbs so you can pull the terminals out of the plug
hook them direct to the switch where you think they should go
Remove the kill wire from the coil and hook up a meter, test light whatever floats our boat to check that it never gets voltage at any key position
Hook the kill wire up & fire up the engine.
Once happy put the terminals back into the plug and refit the switch.
On some switches with metal bodies that go into metal on the mower the ground wire is not ground to the switch but takes ground from the switch body .
Cant be any more specific without knowing model number of the mower so we can look up the schematic and the actual switch make & number.

"Calculator disease". Got to love this guy LOL

slomo