Crossing jumper cable polarity fry a nexus controller on a Generac 36kw generator

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New Member
New Member
Posts: 1
Joined: Thu Sep 03, 2020 6:51 am

My generac 36 kw generator stared like clockwork when Hurricane Laura hit. Ran for two days straight without a problmem. My dealer stopped by just check the oil. All good, except the generator would not start back up. My dealer jump started it. It cranked up anf ran for about 8 hours then died. Nexus controller daid “low voltage”. Dealer came back out to jump start it again. Accidently crossed the jumper cables.(he was exhausted from generator issue calls). The controller went blank. He couldnt reset it. I’m desd in the water with no power when we need it most!
1. Shouldn’t the fuse have protected the controller? Or not?
2. If a battery (or jumper cables) are hooked reverse polarity on this generator, would the starter motor work/engage?
3. Do you think my nexus controller is burnt out?

Top Contributor
Top Contributor
Posts: 205
Joined: Thu Nov 15, 2018 4:19 pm

A fuse can't protect from reverse polarity. The damage has to be done before the current will get high enough to melt the fuse.
Site Admin
Site Admin
Posts: 7632
Joined: Sat Aug 04, 2018 8:46 pm
Location: Clawson, MI

That really stinks :sad: I agree though, that controller is probably wasted...

If you get the serial number from the unit, I can get you the correct controller (or see if he will get it for you).
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