Zumo User Forums

lkraus wrote: ↑Sun Mar 30, 2025 3:45 pm
In the event of a short circuit or 12V input polarity reversal, it just shuts down. It is reset by switching off the ignition or otherwise disconnecting the 12V supply.

reverse polarity, in my testing I think i did that, I think I damaged the dc-dc converter box, disconnecting to 12v doesn't reset the converter, I may have ruined it,

twowheelstom wrote: ↑Mon Mar 31, 2025 12:48 pm [ I may have ruined it,

Maybe. I've read of several cases where reversing polarity did not work, but did no damage. I do not remember if those were the new fuseless converters or the older fused ones.

RESOLVED MY PROBLEM
well, it was a reverse polarity, and I ditched using the battery clamps I was using, and connected zumo cradle power cable directly to the battery posts, and guess what, the 396 powered on, success, I believe the testing I had been doing with the battery clamps was the problem, connecting cradle wires directly to (+) and (-) battery post solved my problem, yahoo, now I realize that I was doing it wrong, no wonder the zumo had no power, my battery clamps are a reverse polarity, whereby the red clamp is the (-) and the black clamp is the (+) lol I am so dumb

You helped me a lot Ikraus, especially with your comment about reverse polarity, your comment sent me on a search to learn what it is and I checked my test clamps and bingo, problem solved, so thanks