mt500 charger vs mt1000 charger in vehicle

[Gocart878]

hi everyone and happy new year, i have 2 vehicle chargers and one is wired into our ladder truck which we dont use anymore its the mt500 in vehicle charger. so i removed it, and plugged in a mt1000 vehicle charger and it started smoking, whats going on here and where is the problem. am i dealing with a negative ground vs positive ground or something? the two power plugs were the same so i assumed they would work together but this i have never had happen can someone explain the differences in the two chargers ?

[thebigphish]

meter the plug to see which side is hot Vs neutral.

[tvsjr]

You know what they say about ASS-U-mptions! You need to check the plug with a meter to figure out how it's wired - most modern stuff isn't positive ground, but there are always exceptions. Smoking isn't a good thing - I wouldn't put that charger back in service without someone knowledgeable taking a look at it to make sure it's OK. You're not gonna like the "dear Chief" letter if you catch the ladder truck on fire.