MooJohn

Heat is caused by resistance. Enough current to melt it like that would have blown the fuse first. Totally trashed fuse holders mean that something was loose or the fuse leads had poor contact with the terminals. I agree that water could cause the added resistance as well.

FWIW, I'm very happy with my plug & play DDMs.

cheez

iTrader: (1)

ok got it, at least 12 awg wire and a good quality fuse holder that has some kind of weather proof cap

pieisgude

iTrader: (2)

I just realized, mine's a DDM kit too. I too bought their harness...And it's definitely crap.

cheez

iTrader: (1)

UPDATE I bought a new fuse holder that said automotive and weather proof from radioshack and it came with 10 awg already connected to it. I bought new connections for the positive and ground cuz they felt cheap and bend easily. I replaced the original wire with 10awg. The only thing I did different was use a 20a fuse instead if 30a just in case this happens again, the fuse will blow instead of melt. I talked to my uncle who is an electrician and he said the 30a was too powerful and thats y it melted instead of just blowing

cheez

iTrader: (1)

Oh I forgot to add that it works! Even better than before, and I grounded to the frame instead of the negative terminal this time

O. L. T.

iTrader: (17)

The ground was likely the issue all along. You are pulling too much current and it happens in surges when the ground is not strong enough to support the line. If the ground is steady and adequate the amperage is constant. If the ground has low potential the amperage is sporadic and surges electrons due to higher potential demand of protons on the other end. It is literally sucking the line dry causing a series of current rushes.

There could be other issues with the power supply of these ballasts as well causing surges, but the point is surges of current do THAT as seen in the pics. If it was just one big surge it would pop instead of melt. But a series of medium surges heat it up instead of popping it. That power supply may indeed draw it's amperage in cycles like an AC power supply (which is inside the converter of the ballast and does eventually turn into AC to power the bulbs at ultra high frequency and voltage). If the ballast power supply is poorly designed it could be drawing in surges as it cycles, explaining the widespread issues others are experiencing. (which is why the ground is so important). The only way to know is to put an ammeter on the line and see if it fluctuates, but you'd need a high dollar one like a top end model fluke auto scope because it will be doing the cycles at a frequency faster than the average volt meter can display the changes at.