put deck now won't run

451johnny

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hi everyone hoping you can help...i put another deck from the same kind of tractor on my YTH21K46 now it starts but when I release the brakes or engage the mower deck it shut down..,I remember someone mentioning the seat switch before.. maybe bypassing it or something ?? would disconnecting the seat switch help ?? don't know anything about it.. got to get this baby running again so
any help would be greatly appreciated Johnny
 

bertsmobile1

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According to the schematic I have for your mower, you have the tamper proof 4 prong seat switch which as the name implies can not be bypassed.
SO get your gun out , track down all of the idiot bastards who posted instructions for bypassing the seat switch all over Your tube & Face book and give them a big thank you right between their eyes.
Don't worry about hurting them because they had no functioning brain in the first place.

If you touched your switch. unplug it then replug it tight.
These switches have a shorting terminal in the plug to prevent you bypassing the switch
The switches themselves rarely give any problems but brainless morons seem desperate to sound like they actually have a brain by assigning every problem from a flat tyre to a con rod through the side of the block to the seat switch.
The simple test is to sit in the seat, turn the key to the on position then turn on the PTO switch.
You should hear the PTO go Klunk if the seat switch is working .

IT is highly unlikely that you would have disturbed the seat switch when changing the decks
However you may have disturbed the reverse switch which according to the schematic I have here will be on the tranny, or on the frame near the tranny so when pushing down on the revers pedal you depress the plunger on the switch.
These do get bumped around and will cause the engine to cut out with the PTO on & the brake off .

The schematic for your mower is up the front of the parts book and the parts book is a free download from Husqvarna
 

451johnny

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According to the schematic I have for your mower, you have the tamper proof 4 prong seat switch which as the name implies can not be bypassed.
SO get your gun out , track down all of the idiot bastards who posted instructions for bypassing the seat switch all over Your tube & Face book and give them a big thank you right between their eyes.
Don't worry about hurting them because they had no functioning brain in the first place.

If you touched your switch. unplug it then replug it tight.
These switches have a shorting terminal in the plug to prevent you bypassing the switch
The switches themselves rarely give any problems but brainless morons seem desperate to sound like they actually have a brain by assigning every problem from a flat tyre to a con rod through the side of the block to the seat switch.
The simple test is to sit in the seat, turn the key to the on position then turn on the PTO switch.
You should hear the PTO go Klunk if the seat switch is working .

IT is highly unlikely that you would have disturbed the seat switch when changing the decks
However you may have disturbed the reverse switch which according to the schematic I have here will be on the tranny, or on the frame near the tranny so when pushing down on the revers pedal you depress the plunger on the switch.
These do get bumped around and will cause the engine to cut out with the PTO on & the brake off .

The schematic for your mower is up the front of the parts book and the parts book is a free download from Husqvarna
First thanks for that important information ..and I think I might have put the wrong model down my friend had given me the hood of his tractor sometime ago because mine got damaged and the reason that came to mind is because this tractor does not have a PTO switch ..the deck is activated by a lever next to the steering wheel.. but the seat switch is exactly how you described it 4 prongs ..I used 2 tooth picks to separate 2 prongs which just allowed for the engine to keep running while releasing the brakes ,,but she still shuts off when I engage the deck lever and she neither moves forward or backwards which is another thing that's driving me crazy..very sorry for that miss information but still hoping you could help as I haven't heard from anybody else...thanks again Johnny
 

bertsmobile1

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Deep breath time
On the back of the mower under he seat should be the ID tag.
So take a photo of it and post the photo .
Us that fix these things on a daily basis can usually nut these problems out if we know what is here in front of you .
 

451johnny

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Deep breath time
On the back of the mower under he seat should be the ID tag.
So take a photo of it and post the photo .
Us that fix these things on a daily basis can usually nut these problems out if we know what is here in front of you .
ok..thanks so much ..i'll be posting it tomorrow
 

451johnny

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Deep breath time
On the back of the mower under he seat should be the ID tag.
So take a photo of it and post the photo .
Us that fix these things on a daily basis can usually nut these problems out if we know what is here in front of you .
sorry I took so long..im having trouble downloading the picture I took of the tag behind the seat into this site ..so im just going to write it ..and it turns out it is the same one I first put down YTH21K46 - MODEL# 960450021 serial #042410A024077 hope you can help me thanks
 

bertsmobile1

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Open the hood and move the PTO lever .
Watch the rods & linkages that move
One of them will depress a lever when the blades are off.
This is the PTO SAFETY switch
Husqvarna usually hide it near the floor behind the dash where it is near impossible to get at .
The brake pedal is generally under the foot boards fastened to the fame rail
It may be inside or outside of the rail .
 

451johnny

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Open the hood and move the PTO lever .
Watch the rods & linkages that move
One of them will depress a lever when the blades are off.
This is the PTO SAFETY switch
Husqvarna usually hide it near the floor behind the dash where it is near impossible to get at .
The brake pedal is generally under the foot boards fastened to the fame rail
It may be inside or outside of the rail .
I did what you said and noticed a ( plug connection ) or ( switch ) between the motor and inside the lower dash panel.. also the rod that locks the brakes in place ran through there ..I also noticed the cable that ran down from the deck lever ..what I did was unplug clean & re-plug that switch and 2 others that came up as I followed the wires ..now what I should of asked was what was I suppose to do once I came upon them ?? my guess is to check to see if they work ?? and if that's the case I would have to go to youtube lol as I have to learn that to.. and I will if I have to.. so please don't give up on me yet as I have to get this baby going ...thanks again Johnny
 
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