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Safety switch problem on Husqvarna Z248F zero-turn mower

#1

L

Loose_Screws

I have a problem with a Husqvarna Z248F zero-turn mower. It's a 2015 model. When I move the steering levers inward with the seat occupied, the motor stops. It seems logical that the problem is probably with the safety switch under the seat. I've removed the seat switch and by using a c-clamp, I am able to depress the switch to close the electric circuit and keep it closed while I move the steering levers inward. The motor still stops after doing that with the seat sensor circuit closed. Can someone suggest where I should look next to fix this problem? BTW, I put a piece of PVC pipe between the steering levers so I can start the motor and keep it running while the seat is not occupied. I have the electric wiring schematic for this mower but it is the worst schematic I have ever seen and of little help. May I hear your suggestions and comments, please. Thank you.


#2

B

Bertrrr

There are safety switches on each of the leavers you mentioned


#3

L

Loose_Screws

Bertrrr said:
There are safety switches on each of the leavers you mentioned
Click to expand...
Yes, I know.


#4

Tiger Small Engine

Tiger Small Engine

Loose_Screws said:
Yes, I know.
Click to expand...
That means one of the steering arm safety switches is bad.


#5

StarTech

StarTech

Don't forget the seat switch connector has a shorting strip that activates when the connector is loose. It also can become damage and still short out the connector. Also seat must be tested electrically not just mechanically. The switch and the lap bars switch are double pole switch with the none depress position being a normal closed switch contacts on both poles.


#6

L

Loose_Screws

StarTech said:
Don't forget the seat switch connector has a shorting strip that activates when the connector is loose. It also can become damage and still short out the connector. Also seat must be tested electrically not just mechanically. The switch and the lap bars switch are double pole switch with the none depress position being a normal closed switch contacts on both poles.
Click to expand...
StarTech, can you please tell me more about this "shorting strip?" Is that the same thing as a shorting block? Thanks.


#7

StarTech

StarTech

In the seat switch connector they installed this strip. Most time is for both poles of the switch, othertime a two prone version is use. But full version looks like this.
1732204438093.png
What I call fingers of the strip get bent and they continue shorting as lifting tabs on the switch just can't lift them the contacts(pins) of the switch assy. Back probe the connector using a continuity (ohm) meter while the connector is attached to the switch and the switch is depress and if these are working as intended then you get an open circuit reading. Otherwise you get a closed circuit reading.

If these are not working as intended simply remove the strip since the connector is not available except as part of the complete harness. Needle Nos pliers usually does the trick.

Personally I would rather replace the connector but I have yet to find a source just for it.

EDIT> I better post the switch details too.
1732205161715.png


#8

L

Loose_Screws

StarTech said:
In the seat switch connector they installed this strip. Most time is for both poles of the switch, othertime a two prone version is use. But full version looks like this.
View attachment 70140
What I call fingers of the strip get bent and they continue shorting as lifting tabs on the switch just can't lift them the contacts(pins) of the switch assy. Back probe the connector using a continuity (ohm) meter while the connector is attached to the switch and the switch is depress and if these are working as intended then you get an open circuit reading. Otherwise you get a closed circuit reading.

If these are not working as intended simply remove the strip since the connector is not available except as part of the complete harness. Needle Nos pliers usually does the trick.

Personally I would rather replace the connector but I have yet to find a source just for it.

EDIT> I better post the switch details too.
View attachment 70141
Click to expand...
I can't do it now, but later I will look at the seat safety switch connector again. It would be great if this is where the problem is. Husqvarna's wiring schematic is so poorly done, I can't make much use of it. It would be nice to be able to put my fingers physically on each wire coming out of that connector and examine the connections end to end. I'd run some temporary jumper wires around the connector if I could better understand the schematic.

Husqvarna Z248F Electrical Wiring Schematic.jpg


#9

L

Loose_Screws

I just figured out the schematic. The black wire going into the connector is the power supply. The blue wire coming out of the connector goes to the left steering lever. If I'm going to bypass the seat safety plunger switch temporarily, I'll want to run a jumper wire from the black wire to the blue wire. If after doing that, the motor no longer stops when I move the left steering lever inward, then I've proven there is a faulty connection in the connector or the seat safety plunger switch.


#10

StarTech

StarTech

One problem. Jumping the switches that are NC (normal closed) would the same as you have not activated them or basically you are shorting to ground

And BTW the Black wire is the ground circuit and not the 12V positive circuit.


#11

L

Loose_Screws

StarTech said:
StarTech said:
One problem. Jumping the switches that are NC (normal closed) would the same as you have not activated them or basically you are shorting to ground
and BTW the Black wire is the ground circuit and not the 12V positive circuit.
Click to expand...
Click to expand...
LOL, I was thinking that it didn't seem right that a black wire would be the power supply when I posted above. I'm pretty sure the green wire is the power supply.


#12

StarTech

StarTech

NO NO NO....Go back to school to learn how to read schematics.
.
You are dealing with a DC ground circuit. In the diagram. The black, green, orange, blue(lap bar switches interconnect), white wire are all DC- grounded in the safety system. Some are hard grounded and others are switched grounded. The whole purpose of this circuity is ground the safety relay, the starter solenoid, and the magneto (ignition coil) depending which switches are activated. The white wire is your magneto kill circuit. Now whoever drew the diagram does have the contacts of the lap bars switches closed when they are actually open in Park/Neutral position (outboard position). Also the relay contacts is also shown as if the lap bars are not in the park position and the relay is operating.

Now there is also one blue wire off the PTO switch that goes the PTO clutch that is a switched 12v+ circuit. Also the Purple wires are switched 12V+ off the "A1" of the ignition switch. One path is to the PTO switch for the PTO clutch and branches off to the Hour meter. Another Purple branch goes to the engine fuel solenoid and the safety relay. Again 12v+ switched circuit. These purple are hot 12v+ whenever the ignition switch is on or in the start position. Now the yellow wire is the switched starter solenoid trigger wire.

Now that safety relay can be a little hard to find if you don't know what you are looking for as it is taped or zip tied to the wiring harness or otherwise mounted.
1732267238730.png
1732268139731.png
This relay is not listed in the parts list but here is a list of part numbers for it.
1732268354054.png


#13

L

Loose_Screws

StarTech said:
StarTech said:
One problem. Jumping the switches that are NC (normal closed) would the same as you have not activated them or basically you are shorting to ground
and BTW the Black wire is the ground circuit and not the 12V positive circuit.
Click to expand...
Click to expand...
While I was composing the post earlier, I was thinking that it didn't seem right that a black wire would be the power supply. I'm pretty sure the green wire is the power supply.
StarTech said:
NO NO NO....Go back to school to learn how to read schematics.
.
You are dealing with a DC ground circuit. In the diagram. The black, green, orange, blue(lap bar switches interconnect), white wire are all DC- grounded in the safety system. Some are hard grounded and others are switched grounded. The whole purpose of this circuity is ground the safety relay, the starter solenoid, and the magneto (ignition coil) depending which switches are activated. The white wire is your magneto kill circuit. Now whoever drew the diagram does have the contacts of the lap bars switches closed when they are actually open in Park/Neutral position (outboard position). Also the relay contacts is also shown as if the lap bars are not in the park position and the relay is operating.

Now there is also one blue wire off the PTO switch that goes the PTO clutch that is a switched 12v+ circuit. Also the Purple wires are switched 12V+ off the "A1" of the ignition switch. One path is to the PTO switch for the PTO clutch and branches off to the Hour meter. Another Purple branch goes to the engine fuel solenoid and the safety relay. Again 12v+ switched circuit. These purple are hot 12v+ whenever the ignition switch is on or in the start position. Now the yellow wire is the switched starter solenoid trigger wire.

Now that safety relay can be a little hard to find if you don't know what you are looking for as it is taped or zip tied to the wiring harness or otherwise mounted.
View attachment 70165
View attachment 70166
This relay is not listed in the parts list but here is a list of part numbers for it.
View attachment 70167
Click to expand...
ST, are you suspecting that the safety relay might be causing the problem?


#14

StarTech

StarTech

Not really as I would suspect either lap bar switch or seat switch being more likely but even a pinched wire can cause problems. This you a ohms or continuity meter to test with.


#15

StarTech

StarTech

Your of instructional videos.

how to test continuity with a multimeter at DuckDuckGo

DuckDuckGo. Privacy, Simplified.
duckduckgo.com duckduckgo.com


#16

L

Loose_Screws

Thanks for all your help, ST. It's cold with quite a bit of snow here in West Virginia. I'll try to work on the mower next week when it warms up a little and the snow is gone. I don't need to mow, I need to use the mower as a tractor now.


#17

S

smallenginerepairs

Loose_Screws said:
I have a problem with a Husqvarna Z248F zero-turn mower. It's a 2015 model. When I move the steering levers inward with the seat occupied, the motor stops. It seems logical that the problem is probably with the safety switch under the seat. I've removed the seat switch and by using a c-clamp, I am able to depress the switch to close the electric circuit and keep it closed while I move the steering levers inward. The motor still stops after doing that with the seat sensor circuit closed. Can someone suggest where I should look next to fix this problem? BTW, I put a piece of PVC pipe between the steering levers so I can start the motor and keep it running while the seat is not occupied. I have the electric wiring schematic for this mower but it is the worst schematic I have ever seen and of little help. May I hear your suggestions and comments, please. Thank you.
Click to expand...
On many zero turn mowers, after starting your mower you have to release the parking brake before moving the steering levers or it will kill the engine.


#18

R

Rifraph48

Cut the wire that goes to the "kill" connection on the magneto module. Then wire a grounded toggle switch to that connection so you can shut the engine off when you want it off. You eliminate all of the annoying "safety" switches as you can fix one and then another fails. When I was a kid long ago, we had no safety anything on mowers and other engines and nobody was ever stupid enough to get hurt.


#19

R

Rifraph48

Rifraph48 said:
Cut the wire that goes to the "kill" connection on the magneto module. Then wire a grounded toggle switch to that connection so you can shut the engine off when you want it off. You eliminate all of the annoying "safety" switches as you can fix one and then another fails. When I was a kid long ago, we had no safety anything on mowers and other engines and nobody was ever stupid enough to get hurt.
Click to expand...
Or you can simply put the toggle switch in series on the wire that is connected to the "kill" connection. That way the safety switches are connected or not based on the switch setting which is under your control.


#20

A

Aquadisiac

Loose_Screws said:
I have a problem with a Husqvarna Z248F zero-turn mower. It's a 2015 model. When I move the steering levers inward with the seat occupied, the motor stops. It seems logical that the problem is probably with the safety switch under the seat. I've removed the seat switch and by using a c-clamp, I am able to depress the switch to close the electric circuit and keep it closed while I move the steering levers inward. The motor still stops after doing that with the seat sensor circuit closed. Can someone suggest where I should look next to fix this problem? BTW, I put a piece of PVC pipe between the steering levers so I can start the motor and keep it running while the seat is not occupied. I have the electric wiring schematic for this mower but it is the worst schematic I have ever seen and of little help. May I hear your suggestions and comments, please. Thank you.
Click to expand...
I am sure you probably checked this, but is the parking brake on? It has to be disengaged for the engine to remain running when you move the control levers to the center. Just in case you missed it!!!


#21

C

cliffeby

Loose_Screws said:
I have a problem with a Husqvarna Z248F zero-turn mower. It's a 2015 model. When I move the steering levers inward with the seat occupied, the motor stops. It seems logical that the problem is probably with the safety switch under the seat. I've removed the seat switch and by using a c-clamp, I am able to depress the switch to close the electric circuit and keep it closed while I move the steering levers inward. The motor still stops after doing that with the seat sensor circuit closed. Can someone suggest where I should look next to fix this problem? BTW, I put a piece of PVC pipe between the steering levers so I can start the motor and keep it running while the seat is not occupied. I have the electric wiring schematic for this mower but it is the worst schematic I have ever seen and of little help. May I hear your suggestions and comments, please. Thank you.
Click to expand...
I posted this some time ago. You need to make sure that the seat and both arm switches are working and aligned. Easy to focus on the wrong part.

I have a Z254 and had a similar problem with the left arm. For over a year, it would cut the engine when it moved just slightly inward. Turned out that the right arm switch was loose. Check it and make sure it is staying closed when the arm is in park. Since I adjusted the right-arm switch, no stalls when unattended in park. I can't recall the cutout functionality, but both switched have to function. It's counterintuitive to have the left arm movement cause a cutout due to a right-arm switch misalignment.


#22

B

Brucewayne

Loose_Screws said:
I have a problem with a Husqvarna Z248F zero-turn mower. It's a 2015 model. When I move the steering levers inward with the seat occupied, the motor stops. It seems logical that the problem is probably with the safety switch under the seat. I've removed the seat switch and by using a c-clamp, I am able to depress the switch to close the electric circuit and keep it closed while I move the steering levers inward. The motor still stops after doing that with the seat sensor circuit closed. Can someone suggest where I should look next to fix this problem? BTW, I put a piece of PVC pipe between the steering levers so I can start the motor and keep it running while the seat is not occupied. I have the electric wiring schematic for this mower but it is the worst schematic I have ever seen and of little help. May I hear your suggestions and comments, please. Thank you.
Click to expand...
First I am always Leary of any safety bypass. Hopefully you have a Fluke meter or equivalent that you can use to see where you may have an open condition on the safety loop. You may want to study the schematic some more because sometimes things begin to click after several attempts to read a tough schematic.


#23

D

dennis morris

Loose_Screws said:
I have a problem with a Husqvarna Z248F zero-turn mower. It's a 2015 model. When I move the steering levers inward with the seat occupied, the motor stops. It seems logical that the problem is probably with the safety switch under the seat. I've removed the seat switch and by using a c-clamp, I am able to depress the switch to close the electric circuit and keep it closed while I move the steering levers inward. The motor still stops after doing that with the seat sensor circuit closed. Can someone suggest where I should look next to fix this problem? BTW, I put a piece of PVC pipe between the steering levers so I can start the motor and keep it running while the seat is not occupied. I have the electric wiring schematic for this mower but it is the worst schematic I have ever seen and of little help. May I hear your suggestions and comments, please. Thank you.
Click to expand...
see if the "brake switch" is not stuck in the brake on position


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