Leisure Battery

On a trip recently got a smell of burning plastic.I found that the plastic on  fuses under the drivers seat (NUEVO 04) on the leisure battery relay had started to melt.Managed to disconnect but we did not have aux.power for rest of trip. I had fitted a new leisure battery just before we set out.Did not change or tamper with the fuses.Any help as to why this happened would be appreciated  Thanks.

It's not at all uncommon for this to happen. It only takes a small amount of corrosion and the contact resistance between fuse and holder goes up and it gets hot.

Another factor may have been whether you charged the new battery fully before putting it in. If not then the supply from alternator to the new battery would have started out very high - possibly close to the fuse's limit and contributing to the problem.

It's often possible to bodge a repair, but IMO the best bet if the fuseholder has started to melt is just to replace it with a new one, as overheating usually causes the contacts to lose their springiness - which then causes more overheating.

https://www.autosleeper-ownersforum.com/t8597p18-nuevo-30-amp-fuse-melting?highlight=fridge+relay

If you plough through the thread at the attached link you'll find your not the first with an o4 Nuevo to have a relay base under the passenger seat melt. I think the split charge relay is actually under the bonnet but a long time since I had that type of van.

I agree with Mojo about the benefit of replacement.

Peter

Thanks a lot  to you both for your quick response .Very helpful.   Kind regards  MPC44