How do you pass-through cables on a vehicle system that's not permanent?

[williaty]

I have a van that's a daily driver but also our tow vehicle when we go on long trips with our squaredrop camper. Right now, the whole power system and solar array for it are mounted in/on the camper. I have a cable inlet in the side of the camper that allows me to bring the solar panel cables into the camper to connect to the SCC. I have long extension cables for the panels so that they can be moved around to chase the sun while the camper hides in the shade. When the camper is being towed, the panels are stowed inside and the cables are pulled fully inside the camper.


As part of a major refit to solve some weight and balance problems, I need to move the entire power system into the van instead. The problem I'm struggling with is how to get the cables from the solar panels into the van. I need to achieve basically the same functionality (SCC inside van, cables run out to wherever the solar panels are sitting, no cabling left on the outside of the van while driving) and have no idea how to get the cables through the body of the van. Unfortunately, the panel gaps on the van are too tight to just run the cables out one of the doors.


Does anyone know of a product that'll allow me to connect/detach the solar panels externally in a fully waterproof way that'll not make a mess/inconvenience for the majority of the year where I'm not using the van as a boondocking rig?

 

[pollenface]

My PV cable goes straight out the tailgate (I shut the doors on it against the door seal). No comments yet from bystanders

 

[williaty]

My PV cable goes straight out the tailgate (I shut the doors on it against the door seal). No comments yet from bystanders

As I said in the first post, the panel gaps on this van are too tight to allow this. The cables won't fit.

 

[Supervstech]

Bulkhead connector?

I use a cable gland box...

 

[williaty]

Bulkhead connector?

I use a cable gland box...

Do you have a link to what you mean with "bulkhead connector"

The gland box is what I'm trying to avoid. Since it requires cables through it permanently to remain water tight, that means I'd be stuck with cables dangling on the outside of the van even when it's in daily driver mode, right?

 

[Supervstech]

More information needed.

Are you against drilling a hole in the van?

If so, you could route the cables along the windshield, feed them into the harness pass-through under the hood...

 

[Supervstech]

Do you have a link to what you mean with "bulkhead connector"

The gland box is what I'm trying to avoid. Since it requires cables through it permanently to remain water tight, that means I'd be stuck with cables dangling on the outside of the van even when it's in daily driver mode, right?

FORTTAR SP21 Series 4 pin Waterproof Connector, 4 Wire Aviation Industrial High Voltage Electrical Heavy Circular Bulkhead Plug Socket, IP67 (Bulkhead Panel Mount, 4 Pin) https://a.co/d/aIFD8du


Should support two sets of panels...

 

[williaty]

More information needed.

Are you against drilling a hole in the van?

If so, you could route the cables along the windshield, feed them into the harness pass-through under the hood...

I would love to avoid drilling a hole but I'm sure it's probably impossible to avoid. I'm in a rust belt state but the van is already 9 years old so it's likely to rust out before too long anyway and one more hole won't make that happen faster.

I did wonder about running the cables through the existing grommet where the trailer wiring harness passes through but then I'd be back to the same problem of having cables just dangling there all year round and having to figure out how to keep that connector from getting crapped up by the weather and road grime. That's probably the most workable idea I've got so far but I'm still not entirely sure how to implement the weatherproofing.

What I'm hoping for is that there's some miracle product that people are aware of that I've just never seen before and it allows me to easily wall-mount a connector or something. As a DIYer, I find that ignorance of the niche products on the market are my biggest limiting factor 90% of the time.

 

[pollenface]

As I said in the first post, the panel gaps on this van are too tight to allow this. The cables won't fit.

I should have read your post properly.

I have thought about punching a hole through the floor of the car and routing the PV cable along the body with either adhesive or magnetic cable mounts.

 

[williaty]

FORTTAR SP21 Series 4 pin Waterproof Connector, 4 Wire Aviation Industrial High Voltage Electrical Heavy Circular Bulkhead Plug Socket, IP67 (Bulkhead Panel Mount, 4 Pin) https://a.co/d/aIFD8du


Should support two sets of panels...

OK, that one is only 1-star but it did lead me to finding others with better reviews. I only need 2 pins, so I can go down a size and it looks like some of them have water-tight screw on blanking plugs when not in use.

That just moved to the top of the list. I'd have to think through if there's a way I can install it in the bumper or something to avoid drilling a hole in the sheetmetal. Of course, then I have to figure out how to waterproof the backside of that.

Interesting idea. I'm going to think through that one! Thanks!

 

[Rocketman]

Have the wire go under the hood. There are usually some grommets that allow wires to be pass from the engine area to the passenger area.

When using as a driver, the wire is just sits under the hood - no issues…

Good Luck

 

[0truck0]

So, the power is going to be used in the camper but the batteries and everything will be in the van, and the solar panels on the ground?
You don't go through the body, you go through the floor, between the fender and the inside wall perhaps. Use an Anderson plug that hangs out at the bumper like any tow wire and just let it rest on the bumper or however you want. Or let it hang down below the vehicle.

I would use a 4-pin trailer plug instead, mount it to the rear of the van, bumper or whatever works since you didnt show pics, and just plug in when needed.

https://www.etrailer.com/Trailer-Wiring/Pollak/PK11410.html

I use:

https://www.etrailer.com/Trailer-Wiring/Pollak/PK12801.html

It works similar to the typical trailer 7-pin plug, but is intended for heavier gauge wire.

 

[Tomthumb62]

As part of a major refit to solve some weight and balance problems, I need to move the entire power system into the van instead.

If you haven’t looked into it yet, consider a sway bar system for your trailer hitch. Makes a HUGE difference in how it feels to pull a trailer. No more fishtailing and it just feels very solid and easy to pull compared to without one. Side winds are no longer the same problem, either. We notice little difference now whether or not our 30 gallon water tank in the trailer is full or empty.

Not sure if this is what you meant by weight and balance problems, but if so, it could solve your issue.

 

[williaty]

So, the power is going to be used in the camper but the batteries and everything will be in the van, and the solar panels on the ground?

Close. Some of the loads are in the van as well. Right now, we have the battery in the camper and feed the loads in the van (mostly the fridge but also charging for some of our gear) via an umbilical from the camper. The problem comes when we get several cloudy days in a row and need to charge the battery from the van's alternator. Right now, we remove the battery, transfer it to the van manually, drive around for a few hours, and then put the battery back in the camper. Plays hell with the battery monitor, obviously. It'd be nice to have the battery in the van for that reason as well. Plus, when we're not at the camper, there's absolutely nothing in there consuming electricity. By kWh, about 70% of our total consumption is the fridge, which is in the van. My CPAP makes up a lot of the rest with the vent fan and furnace in the camper rounding things out.

The weight/balance reason for moving it will be addressed below in reply to the other poster.

You don't go through the body, you go through the floor, between the fender and the inside wall perhaps. Use an Anderson plug that hangs out at the bumper like any tow wire and just let it rest on the bumper or however you want. Or let it hang down below the vehicle.

My concern with Anderson stuff is that it's in no way weatherproof and I've never seen one of the weather sealing boot things actually stay completely dry inside. Since Supersvstech mentioned those bulkhead connectors, I found the same connector type (SD20) in an inline form. I'm considering letting that dangle out the back of the van via an existing wiring grommet since the screw-on cap on the SD20 is more likely to remain waterproof.

 

[williaty]

If you haven’t looked into it yet, consider a sway bar system for your trailer hitch. Makes a HUGE difference in how it feels to pull a trailer. No more fishtailing and it just feels very solid and easy to pull compared to without one. Side winds are no longer the same problem, either. We notice little difference now whether or not our 30 gallon water tank in the trailer is full or empty.

Not sure if this is what you meant by weight and balance problems, but if so, it could solve your issue.

Unibody cars can't use weight distribution/anti-sway hitches. The lack of a frame means they can't withstand the forces.

What went wrong is that our squaredrop doesn't have a rear galley in it (came that way from the factory). That means there's a lot of weight missing from behind the axle and the factory didn't move the axle forward to compensate when they built it. Because of that, the tongue weight is too high (about 25% of the trailer weight) and we have to delibrately shift all the heavy stuff to the back of the camper for towing to get the tongue weight down to the correct values (10-15% of trailer weight) and also get it under the tongue weight limit for the van. One of the big heavy things we put back there is the battery but it can't stay there while we're in the camper. So the damned battery has to get shuffled forwards and backwards every time we move the camper to a new location. It's just annoying and is one of the things that causes enough friction to keep us from doing more remote trips where we end up driving for several days (with single night stays) to get where we want to be.

 

[Tomthumb62]

Unibody cars can't use weight distribution/anti-sway hitches. The lack of a frame means they can't withstand the forces.

Ah, ok, today I learned, thanks.

 

[0truck0]

How water tight are the clamps on your van's starting battery? So what if the Anderson plugs get wet? 99% of trailer connections to vehicle are not water tight.

Look at that two-pole plug from etrailer.com

I literally used this exact one to charge a bank of batteries in a trailer from the tow vehicle. It works great.
If you have two systems (need 4 poles) then just get two, or get a similar plug/socket that has 4 poles.
I still have it and intend to put on the new truck soon.
That and big enough gauge wire is all you really need to connect van and trailer electrically.
hint: I ran wire from the starter motor since it already has big wire going to it and is not used while driving. I put a mechanical solenoid switch as close to the power source (starter positive connection) as possible and switched that with a toggle in the cab that was powered from the ignition (radio fuse) * fuse panel, when truck is off (key off) the connection is off, so you never accidentally drain your starting battery when parked. All this of course is powered off the alternator while driving.

I had a camper where I cut a hole in the floor and dropped the batteries down from inside. They were under the floor, accessible from above, yet rode below the floor, outside. Possible bc they were still higher than the axles. That same etrailer com site has battery hanger baskets too so you could make one or buy it. I made mine out of large angle iron.

* see also "fuse tap", available at any auto parts store.

 

[wme]

https://www.andersonpower.com/us/en...68-waterproof-connector-series-sbs-x-75a.html

 

[HarryN]

A friend of mine had a similar problem with too much weight on the trailer tongue.

I built this linear power system for his trailer. Here it is, installation not quite complete.

The batteries were moved to the very back and it all fits along one wall under the fold down bench seat.

There are 400 watts of solar on the roof of the van and another 400 watts on the trailer.

He can move up to 600 watts from one to the other (either direction ) using 120 vac. It is much safer than using DC methods.

I would look first at moving the batteries toward the back of the trailer if you can. It has a big impact.