Aha, I have an idea. Instead of the J-lock, which only locks one wheel (that can still be dragged), I will install a second breakaway switch underneath the trailer, but pointing backward. Will wire it in parallel with the first. Then I'll loop the cable through the wheel holes. Then if the trailer moves forward the brakes are activated. I'll put a hub cap over that wheel so as to hide the wire; A theif might see the wire think it's a lock and cut it, defeating the purpose.
It's not a deterrent but it's cheap (less than $20), easy, hidden, and most thieves will not be aware, unless they read RV.net and know where the RV will be stored :B I'd had a second breakaway switch on my "to buy" list anyway, as a backup. So I'd have bought one anyway.
I'd have to keep the batteries topped off but I was going to get a solar trickle charger anyway.
I also have an old house alarm system that I couldn't get to dial out properly, and the eBay seller disappeared off the planet so I couldn't return it. That's going in the trailer, too.
As mentioned, the RV will be stored in a neighborhood with meth labs nearby and it will sometimes not be attended. But I can have several layers of security for not too much cost or effort:
* Fenced yard. Not a strong fence, and the RV is perfectly visible from the road. It would be a psychological barrier mostly. Free
* Nice sodium halide street lamp already installed right above the parking spot. Free
* Alarm system; Already own it, but can be obtained for less than $50
* Coupler lock, $15, will use the one mentioned in the opening post and slip some collars around the shank
* Hitch lock $15, would have bought anyway
* Hitch installed in the coupler; Free
* Hidden breakaway switch and some extra wire; $20, would have bought anyway
* Solar trickle charger; $50, would have bought anyway
* Not a very expensive looking trailer; Free :B
If only I could convince the person who lives there to get some dogs I'd be set :B And if I really want to get fancy, for
$37 Amazon has a GPS tracker (see this for reviews), coupled with a
$19 SIM card (no monthly fees, no top-off requirements, only have to send it one text message every 6 months) I can track it if it gets stolen. $56 total and no monthly fees.
Yes, RV theft is rare. Yes, if a theif wants it they will take it. Yes, you only have to have stronger security than your neighbors. It's just that these options are inexpensive, not too much hassle, and I either already own them or would have bought them anyway. I'd really hate to lose our trailer for lack of some simple solutions. Not too much trouble for a lot of peace of mind.
Will try to update this thread as I make progress.