Faulty Sevcon controller

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Faulty Sevcon controller

Post by Ribfeast »

My girlfriend parked up the Toro Workman MDE 48V kart yesterday and then went to use it later in the afternoon, it makes all the right noises (reverse beep etc) but the main contactor doesn't click on, and getting 4 flashes on the dash.
Tried bridging the 2 large terminals on the contactor to allow current flow but this didn't make a difference.
Applied 48V to the contactor and it clicked over fine and reads 0 ohms when energized, so it appears OK. So it seems the Sevcon isn't outputting a contactor charge to energize it. It's now just giving 3 flashes which indicates the controller is likely faulty :(

So it appears that I have a faulty Sevcon Millipak controller. Does anyone know where I can get one of these affordably? Most seem to be around $700-1000US :(
It's a model 633T46301.
Are some of the other visually similar models interchangeable? eg: https://www.cartpartsrus.com/SevCon/sevcon.htm
I think these work by switching things to ground, vs switching to positive, so not sure if I can change to another brand of controller.

If I was to buy a new Sevcon, would it need to be programmed also? Or just plug and pray?
Does anyone maybe have a good one they are selling?

I've pulled it apart and it's full of that black potting epoxy, so I'm going to have a hard time getting to the innards to try and repair it otherwise. Has anyone repaired one successfully? Any tips on getting the epoxy out safely?

Thanks for any help :)
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Re: Faulty Sevcon controller

Post by IanKidd »

Hi Bibfeast...I have the same problem that you seem to have. I'm in Stanthorpe QLD, and wondering what you've done to solve the problem. My Toro Workman MDE did the same thing on Saturday morning, and I've been trying to work out which component is faulty. I suspect it's the Sevcon Millipak, but hope it's only the contactor/solenoid. Regards Ian kidd Stanthorpe.
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Re: Faulty Sevcon controller

Post by andrewf »

Did anyone work this out. From what I've determine you can buy a new controller from Toro for about $3.3K, but you can directly buy one from the US from a few places for ~$1KAUD. What I'm not sure is does a standard one not from Toro requiring programming. One person said it will be fine, but hope to hear other's opinions?
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Re: Faulty Sevcon controller

Post by jonescg »

Sevcons are notoriously dificult to program. You basically need a computer science dregee to set them up 😒. But generally they are a solid piece of equipment once set up.
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Re: Faulty Sevcon controller

Post by reecho »

Maybe try Rod at EV Power in WA. He represents Borg Warner (Nee Sevcon).

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