TS 242 suspect smart switch issue

[sarg13]

My sisters husky is having issues with smart switch I suspect, mower starts ok then you engage blades no problems, then mows fine, when you disengage the blade switch the engine shuts down. It does it fairly consistently, I have an electrical trade background so have bypassed and checked the interlocks as per the wiring diagram with no change to the fault.
I see a lot of people have had weird things occur with faulty start switch logic, but they are expensive to buy and I won’t be popular if fault is still there. Have thought about installing old style ignition switch set up and get rid of the smart switch, if anyone has some good info on that process that would be great.
If anyone has had similar issues and found a fix your info would be appreciated.

 

[StarTech]

I have read several posts over the years where users change over to a regular keyswitch because problems with the smart switch.

Here is a schematic of a TS242 that uses the regular keyswitch setup.

I would think that you only need the wiring harness and the keyswitch to make the change over.
The harness PN I see is 585555301 and the keyswitch is PN 532193350. Now I don't if the key comes with the switch but most likely not so it PN is 532411935.

 

[bertsmobile1]

I have not done one on your exact model but have changed several to standard switches on both Husqvarna branded mowers and off branded mowers made by Husqvarna.
In each case where the original model had a standard key, Husqvarna had simply used an add on harness for the smart switch
All I really need to do was unplug the smart switch & plug in the standard switch plus add a few wires that were left off the original harness.
Even the switches were the same ones ( 4 pin ) used for standard wiring with only one set of contacts being used.
The only hard bit was the switch plug which I could not get so I used standard terminals insulated with heat shrink tube then potted them together using a vegemite jar

 

[sarg13]

I have read several posts over the years where users change over to a regular keyswitch because problems with the smart switch.

Here is a schematic of a TS242 that uses the regular keyswitch setup.

I would think that you only need the wiring harness and the keyswitch to make the change over.
The harness PN I see is 585555301 and the keyswitch is PN 532193350. Now I don't if the key comes with the switch but most likely not so it PN is 532411935.

Thanks for the info, that’s great, I will check out wiring diagram and compare to smart switch loom to see if I can just modify existing harness and attach connectors required for standard ignition, cheers…

 

[bertsmobile1]

Download the parts book from Husqvarna ( free )
All of the on line diagrams are virtually unreadable
On the ones I have done, they all had a plug to connect the smart switch to the standard harness which was not shown on the diagram.
Now perhaps this is because they were running out the old harnesses , I don't know bit it did have me confused for quite some time till I twigged

 

[StarTech]

Well here is the start switch wiring diagram.

Its wiring harness is PN 585216001.

 

[StarTech]

Also this what the back of the smart switch looks so a standard for a non smart switch will not work.

It use a 10 x 2 connector.

 

[bertsmobile1]

Yes that is some thing like what I saw
Note the connectors are not shown in the schematic
Most of those wires will bypass the switch so just get plugged into each other when a key switch is retro fitted.
Not strait plug & play but a lot easier & quicker to do than stripping out the whole loom & swapping with a dumb switch loom.
The looms down here go for prices that exceed the outrageous prices of the smart switch and usually have to be ordered directly from the USA because they are not stocked locally so a 1 month wait which is why I originally did the bypass.
I would rather the $ 400 went into my pocket than Husqvarnas pocket

 

[sarg13]

Thanks again, I did manage to get the smart switch wiring diagram and spread it over 2 A4 pages to follow circuit layout, I have started modifying a harness off another ride on mower so I could use it as a test subject to bypass the smart switch to prove its the issue, if I had a 10x2 connector the same type that would make it easier to attach to test harness then plug it in, in place of smart switch, bit of stuffing around, best to just modify it permanently.

 

[bertsmobile1]

The first one I did I wanted to get the switch tested but was told there was not a single test unit in Australia but I could send it to the USA for testing.
I was tempted to do that, but the customer wanted their mower.
Three different dealers told me they test it by substitution .
A very expensive way of doing it as the units are around $ 400 locally and if there is a wiring fault that blew it in the first place you spend $ 400 to verify that then another $ 400 for a third unit .
No surprise that they went back to keys
Really annoying as the unit I pulled apart would cost less than $ 50 to make and another $ 5 to put a diode & fuse in there .
I would not mind paying $ 400 for a quality item but not for very cheap junk.
The most expensive bit is the printed front cover .
Pull your old one apart when you have finished bypassing it.
Just about every one that failed was in a mower that had been sitting unused for extended periods so my guess is they fail because of voltage spikes.