Battery Disconnect melted.

[Jpsmith53]

I have a 2010 3150 and I noticed that the Battery disconnect relay has a terminal that has melted the housing. I cannot find a replacement on line. Any help would be appreciated. Jim

[Montana Man]

If that is the factory installed battery shutoff, remove it and put one in that actually shuts off the battery.

[DmaxDually]

Is it one of these?

https://www.trekwood.com/products/14...ery-Disconnect

https://www.trekwood.com/products/14...-Plt-Key-Chain

[Dave W]

Install a real battery shutoff instead of replacing that useless one that doesn't shut much of anything off but the converter. The failure may have been a loose connection. I usually use a Cole-Hersee. These are sold under many brand names, Longacre being one of the best(and, of course, most expensive but less then Trekwood's unknown amp capacity piece)

[Billyj571]

I only use the Cole-Hersee in my boats and trailers just my 2 cents

[BB_TX]

I would guess a loose or bad connection at that terminal. The burned wire and the nut with the finish burned off indicates localized heating at that terminal. Although it could have been an internal bad connection.

Are there any markings on the switch? Numbers, manufacturer name? Picture is not clear, but is that a third terminal on it on the extreme right side of the picture?

[Jpsmith53]

So, upon further investigation.... It is actually the Reverse Polarity Relay for the Slide Hydraulic Pump. The "slide in" side is getting hot. It's a 90 Lippert part. Don't know if there is a better option, but I certain that ther must be a better part. And it is true; the Batter Disconnect only seems to disconnect the charger. Thanks for the help.

[BB_TX]

I thought that might be the case from the picture and seeing a third terminal. Technically called a reversing polarity DC contactor. Those have not been reported as a component with frequent failures. Trombetta is one manufacturer of those. And googling reverse polarity contactor RV shows Trombetta to be much cheaper than the Lippert named ones.

I am still of the opinion that a loose/bad wire connection (meaning resistance) caused the localized heating. The formula for heat dissipated in watts is power = resistance times the current squared. With that much current squared it doesn’t take much resistance to create a lot of heat.

[mazboy]

My battery disconnect, when leaving the trailer, is to just disconnect the negative lines.