Has anyone else got dodgy electrics in their van after heavy rain?

Yeah, had this exact problem last summer. Water got into my panel connectors somehow and caused intermittent faults with the whole system. Took ages to track down because it'd work fine in dry weather then play up after rain.

The issue was moisture creeping in around the cable glands where my solar feeds into the van. Switched to proper marine-grade connectors and sealed everything with silicone. Haven't had a repeat since.

What's happening with yours? Is it the solar side or mains electrics? That makes a difference with how you'd troubleshoot it. If it's the leisure battery system, I'd check:

• All connector terminals for corrosion (green stuff = bad news)
• Cable glands around penetrations
• Whether your fuse box is getting damp
• RCD trips (mine kept doing this)

The annoying bit is vans aren't designed with electrics in mind — they just bodge cables everywhere. Worth getting a proper look at the cable runs and seeing if any are exposed or poorly routed where water could sit.

If you've got a Victron system, at least their kit's robust, but the connections between components are where it usually fails. Same with most setups really.

Does the system completely cut out or just lose certain circuits? That'll tell you whether it's a main issue or isolated to one part.

Moisture in connectors is basically a guaranteed way to turn your electrics into a temperamental nightmare — mine did exactly the same thing last year and I spent three weeks convinced my Victron was haunted.

Pro tip: silicone grease on all your panel connections is a lifesaver, but honestly the real culprit is usually dodgy gland seals around where cables enter the van. Check those first before you go full conspiracy theorist blaming the weather.

If it's still playing up, consider wrapping problem connectors in self-amalgamating tape as a temporary fix whilst you sort proper sealing. Drying everything out completely (hairdryer method, not glamorous but it works) often gets you back online in the meantime.

This is such a common culprit on boats and vans — moisture in connectors will drive you absolutely mad. The intermittent nature makes it genuinely difficult to diagnose because everything looks fine until humidity spikes.

Worth checking a few things whilst you're investigating: MC4 connectors especially are prone to this, so consider swapping to sealed alternatives if yours are exposed. Silicone grease on the contacts helps, though prevention is always better. I've also had luck with those little desiccant packs tucked near junction boxes.

If you've already traced it to the panel connectors, Victron's IP67-rated connectors are bulletproof but pricey. For emergency peace of mind, you could isolate that string temporarily and see if your faults disappear — confirms the diagnosis at least.

The real fix might be improving ventilation or adding a vapour barrier behind the panels if they're mounted flush against something. Bit of breathing room makes a difference on narrowboats anyway.

What kind of symptoms are you getting now — complete dropouts or just voltage fluctuations?

Been there with my narrowboat setup. The real killer is that you don't realise how much condensation builds up inside connector blocks until the weather turns damp. I learned this the hard way when my Victron MPPT started throwing phantom faults after a particularly wet spell.

What sorted me out was investing in proper sealed connectors — specifically MC4 connectors with integrated IP67 rated junction boxes. Sounds expensive but it's nothing compared to the troubleshooting headaches. Also sealed up all my cable entry points with silicone and added breather caps to my battery enclosure so moisture doesn't just accumulate.

The intermittent nature is exactly what makes it so frustrating. You'll be cruising along thinking everything's fine, then suddenly lose half your system. Worth doing a proper audit of where water can actually get in. Sometimes it's not the obvious places.

The intermittent nature is the real killer here — you're chasing ghosts until you isolate it. Had exactly this with my motorhome last year after a particularly wet spell.

What finally cracked it for me was systematically disconnecting and reconnecting every single connector whilst monitoring voltage with a multimeter. The culprit was moisture oxidation on the battery terminals, creating resistance that'd vary depending on temperature and load.

Worth checking:

• Battery posts and terminal clamps (most common)
• MC4 connectors on solar panels (the seals degrade over time)
• Any exposed breaker terminals

For prevention, I switched to dielectric grease on all connections and sealed my external connectors with IP67-rated junction boxes. Victron's connector covers are decent too if you're retrofitting.

@Hamish1975 — did you eventually find where the water was entering, or just seal everything once you'd identified the dodgy connector?

Spot on about the intermittent gremlins, lads. I'd add that it's worth checking your cable glands and breather holes on your battery box whilst you're at it — often overlooked but they're prime suspects for moisture ingress.

@Hamish1975, when you sorted yours, did you use silicone sealant around the connectors or did you go for proper marine-grade connector covers? I've found those little rubber boots make a world of difference, especially if your van's parked up for extended periods.

One thing that helped me was running a small desiccant pack inside the electrical cabinet during the wetter months. Doesn't solve the root cause obviously, but it's bought me time whilst I tracked down where the water was actually getting in. Worth considering as a temporary fix if you're still debugging the problem.