They can be handy, but really don’t do anything you can’t do with a multimeter and some wire.

Poking around in a 12V only system where you don’t have a good idea how something is wired, it can be handy to quickly identify ground and 12V wires. Since most RV circuits are pretty simple, it doesn’t have a big advantage there.

It can also be used to apply 12V or ground to something. Think testing a relay. You know the relay isn’t doing its job, so you probe both sides of the coil and find no 12V but ground on both. You use the probe to apply 12V to the positive side of the coil. If the relay engages, you know the problem is with the control signal. If the relay doesn’t engage, you know it’s a bad relay. Again, the level of complexity of most RV circuits doesn’t really need it, and even when it does, you can always use jumper wires and a meter. The control board for a water heater might be a place the power probe would be helpful if you have the circuit knowledge.

I used one helping a guy fix the wiring on a boat that had been butchered by a previous owner. It was handy, but not indispensable for that.

I’d be a bit nervous about people in general using one in the mixed 120VAC and 12VDC environment of an RV

Brian - I am old school and look it . I have always used my analog tester from Radio Shack (now upgraded thanks to Jim) and a few cobbled together wires., alligator clips and T-pins. Now having said that a simple probe could save some time.

Keith

PS - You folks have got to stop spending my $$$$$$.........................but you folks love it

Keith

The multi-meter does not supply power or ground, it only samples the circuit. A power probe can be very useful. You can test for power or ground, as well as, supply power or ground all without changing settings or connections. I own and use one regularly at my day job. You can get by without one as Jkwilson suggests but if you are a tool geek (like me) or just want the added simplification they are good to have.

One main benefit when supplying power is that they have an internal breaker. If you just hook up a wire to your battery and poke it into your trailer connector to light up your running light circuit and miss, you could turn that wire in to a heating element. The power probe will just open the circuit and then reset when the overload is gone.
Trib

I've never been a fan, but mainly because they are not accurate enough for what I was doing, that being said you don't need accurate with an RV..lol
For me, if you want one, it comes down to what TribForce said...simplification. You can do everything a multimeter. But you need to think a bit about using it and having it on the right setting, leads plugged into the correct spot etc.I keep a couple alligator clip jumpers in with my meter for sourcing, grounding and jumping though I rarely use them.

IMO, If you already have a multimeter and know how to use it, I wouldn't bother.

Do you know what will happen if you probe 120V with a power probe? I don’t know if they are overload protected for that much or not.

I don't know what would happen but I would bet It might not be good. Most of the people on this forum are highly skilled and capable of diagnosing complex problems. A DIYer must know the difference between his high and low voltage systems before attempting his/her own repairs.

I suspect the same. It makes me cringe a little at the thought of a novice using one in the mixed voltage and haphazard wiring environment in an RV.