New to solar, new camper, issue getting power in.

[cobes]

Hey folks,

Trying to get an idea on how to troubleshoot an issue. New to solar and this is my first time using a multimeter too so appreciate some help. I just got a new camper, and it has be pre-wired for solar. The first time I hooked up my panel, and then went into the camper to plug the input Anderson connector into my Goalzero, I was not getting any input power.

Some details on equipment.
- Merlin 170 Watt panel. Used multimeter and read 23.4 watts and 7.4 amps directly from the panel.
- Goalzero Yeti 1500x.
- Camper is a Vagabond Drifter, with wiring from the outside to in.

I've already tried stepping back to try to get a reading at every connector. And with the panel plugged into the MC4 connectors on the roof, I was not able to get that same reading at the first junction which is an Anderson connector(see attachment).

Pictures are of the roof where the 2 MC4s meet, the first change inside of that same corner about 10" later, and then the exit and input Anderson connector in the bed. As far as I can tell, nothing has been switched. Red connectors are matched with red wires. The MC4 connectors themselves on the roof have the opposite polarity than the wire suggests, but I assume that's just the connector they had on hand and don't really have a way of testing that I don't think.

The box on the roof that passes the cable through I don't know much about, I don't think there's any connectors inside. The negative MC4 off the panel was not connecting perfectly to the negative MC4 on the camper. The latches didn't lock completely, so I filed down the end of the MC4 to get it to clear and catch but still no luck. I'm wondering if the MC4 specs are slightly off and the pins inside aren't properly meeting?

So not sure how to go about finding the issue. Any help would be greatly appreciated. Can give more details and pics if needed.

Thanks

 

[PSea]

me being a smartass: your bed requires an anderson plug? ;-)

23.4 watts or 23.4 volts? assuming it's volts. whichever length of wire isn't getting voltage is your (first) problem. if it is watts, i'm guessing that's too little for the goal zero. reverse polarity sounds like another problem. but that should effect getting voltage readings at the end of wire.

second point, what's the max voltage the goal zero can handle? you want to make sure the panel is within the goal zero's tech specs.

 

[cobes]

me being a smartass: your bed requires an anderson plug? ;-)

23.4 watts or 23.4 volts? assuming it's volts. whichever length of wire isn't getting voltage is your (first) problem. if it is watts, i'm guessing that's too little for the goal zero. reverse polarity sounds like another problem. but that should effect getting voltage readings at the end of wire.

second point, what's the max voltage the goal zero can handle? you want to make sure the panel is within the goal zero's tech specs.

I don't know enough to know why the comment about Anderson connectors is funny but yeah that's one of the few solar inputs available and the one that was easy for them to wire. Is there something wrong with that? The other option is a 6mm plug.

And definitely volts haha. Again pretty new to this stuff.

Reverse polarity just meaning something is switched? I'll try to look at the connectors to see if something is up but also don't know exactly what to look for.

This unit can take up to 50V and 10A so should be good.

Appreciate the help.

I will assume you meant 23.4 volts...
Your comment about measuring “7.4 amps directly at the panel” tells me you really do know to use a multimeter. Or you just got lucky to not blow its fuse or damage it. I will elaborate later..

Successfully measuring voltage directly at the solar module, but finding nothing inside just inches away sounds like its a connector problem.
Fwiw,
‘MC4 connectors’ are not all equal.
Between manufacturers, There are slight differences in quality and dimensions. As you found, a connector did not quite mate up perfectly...
Said that,
I would start on the roof. Since you measured voltage directly from the solar module. Carefully examine the MC4s coming out of your roof. (that box on the roof should be just a weatherproof pass thru. But who knows, its possible it contains empty fuseholder or incomplete splice...)

Once connected to the solar module, You might try to unscrew the gland seals on the backside of those roof MC4s then probing their backside measure for voltage there.

More comment on MC4s.
MC4s can be confusing regarding gender and polarity.
Typically positive coming from a source such as solar module is the female connector, male connector is negative.
Male & female refers to the metallic part what makes electrical connection. Not the configuration of the plastic connector parts.

Regardless of wire colours, Its always best to measure polarity before making final connections. Especially so with wiring and connectors you did not install yourself.

Measuring Amps.
Typically amps are never measured directly in parallel from a powersource.
An ampmeter is normally connected in series with the source and load.

In your lucky scenario, that 170W solar module cant produce more than about 7.5 amps. Which is within the 10A maximum of typical multimeters.
Had you tried measuring amps from a battery or similar source, at minimum you would be replacing a fuse within your multimeter.

Thanks for all that information, that's great to know. I'll take a look into the connectors and see what I can gather. And thanks for the clarification that the MC4 connector male female refers to the pins inside and not the plastic, that makes sense but also is now confusing to talk about haha. Can confirm that the positive coming off. The panel is indeed female. Corresponding male connector on the roof is also positive at least from what I can tell on the wire. It's going to be a pain tracing the wires down to see if anything got switched but that'll be my next step. The probe for my multimeter did not fit into the plastic channel on the female /positive panel cable so I had to take it apart to test it. That's where my idea of perhaps the pins inside not meeting up came from, but it's kind of hard for me to tell. One option I guess would be for me to get two sets of same origin connectors and attach them to the existing cables? Thanks again for the help, I appreciate it

 

[Wallygator]

https://thecampingnerd.com/goal-zero-yeti-solar-panels/

Here is a guide I found. Good luck sorting it out.