Thursday, September 21, 2023


RV Electricity – WAGO 221 splicing block is welcome innovation

By Mike Sokol

Dear Readers,

This could be the greatest innovation in wire splicing technology since the invention of the wire nut. And it looks like the RV industry is adopting it quickly. It’s the WAGO 221 lever action splicing block.

Why am I excited about this? Well, traditional wire nuts are notorious for being difficult to install properly, especially once you’re trying to splice more than two wires together. Plus, it’s difficult to get a visual indication of proper termination. Yes, wire nuts are a big failure point in RVs (as well as home wiring).

A few months ago when I was teaching an RV technician class one of the senior technicians gave me a WAGO 221 splicing block to play with. So I threw it in my glove compartment and forgot about it. However, just last week I was doing a consult on an RV that had developed a hot-skin voltage condition, and the repair shop foreman showed me a big box of WAGO connectors in all sizes, and said that Forest River was now using them on their new RV builds, and that his technicians loved them. So I took a few home to try.

Well, I do believe this is a great advance in reducing electrical failures due to overheating and intermittent connections due to improperly installed and maintained wire nuts. That’s because 1) the WAGO connector is clear, allowing you to clearly see when the conductors have been properly stripped and seated; 2) they clamp down with a spring-loaded lever you can’t over-tighten and which can’t loosen up from vibration; and 3) the more you pull on the wire, the tighter it grips the conductor. Very cool. It appears that Progressive Dynamics (the company that manufactures the circuit breaker panel in your RV) is utilizing the WAGO connector instead of screw termination in some of their products. Now, that’s getting interesting!

I’ve already contacted WAGO for technical literature and some samples to experiment with, but these lever-action splice blocks could go a long way to reducing wire nut splice failures in your RV. And yes, you can indeed get them on Amazon.

So are wire nuts dead? Certainly not. But unless they’re installed properly to begin with they can be a big source of failure and frustration in RV electrical systems. And if improperly installed they can become a source of overheating and a possible fire inside the walls of your RV. If used in any kind of moving vehicle, they really should be secured with electrical tape to prevent them from loosening up due to road vibration.

OK, everyone. Remember that electricity is a useful and powerful force, so we all need to pay attention to safety precautions while using it.

Mike Sokol wrote this in 2019 when he was a columnist for He has since moved on and is therefore unable to respond to comments.

Learn more about RV electricity at the RV electricity group on Facebook.

##RVDT 1188;##RVT918


  1. Looks promising, but here in Canada way to expensive for regular user.
    The link to Amazon list a $20.97 price for a box.
    The same in Amazon Canada is $87.99

  2. Hi Mike,
    I’ve never seen a WAGO connector so pardon my ignorance. Is there sufficient surface area of connection? With a pair of wires are twisted or a wire is wrapped around a terminal and the screw tightened there is a good deal of area of connection for current passage. Is this a potential problem?
    Keep up the great work.

  3. Mike,
    The problem I see with WAGO connectors is that they make it easy for unqualified people to do electrical work. If you can’t install a wire-nut correctly, you shouldn’t do electrical work.

    • That’s probably true, but wire nuts really were not designed for the high vibration environment of an RV. The WAGO connectors could help eliminate connection failures in the field. Time will tell…

    • Before there was Romex and wire nuts, there was Knob & Tube wire with lead soldered splices. I actually helped an old timer electrician do the solder splicing when I was a little kid, maybe 10 years old. We used a gasoline blowtorch to melt a crucible of lead, then held the molten lead above our heads to dip the splice joints in. Finally we wrapped the base connections with fabric (not PVC) tape. Boy how times have changed.

  4. I have these on my Grand Design and so far I have found six of them with the lever flipped open. These have been replaced with crimp connectors and the rest will be as I come across them.

    • Could you save a few of the connectors so I can do forensic analysis on them? I’m really curious as to what the failure mechanism could be.

  5. I recently bought a Progressive Dynamics Automatic Transfer Switch, PD5110010Q. Instead of the normal screw connector bus, it came with WAGO’s. Taping up the each connector lever is a good preventative measure.

  6. The first inverter in my fifth wheel was a Xantrex 2500 watt & after 4 years of fulltiming, it burned up inside due to road vibrations loosening up the wire nuts connecting the incoming lines. It literally burned up inside, but fortunately did not damage the rest of the rv. My current Xantrex 3000 watt pure sine has a totally different type of wire terminal set up.

  7. Mike, I’ not convinced that the waggo is any better. I have brand new 2020 sports coach and the 12 volt lights in the bedroom and rear bathroom stopped working. Being on the road I started to investigate, I’ll give you one guess where the failure was. If you lift up on the orange tab the wire will release and no matter how hard I tried it would not stay closed. Now all three wires are soldered together, wire nutted and taped. Any mechanical connection is a failure point and I hope they did not use them on high current loads as I feel that by pinching the wire does not give good current varying capacity.

    • Was the wire too large for the WAGO connector? Do you have any pictures? I’ll be talking to WAGO engineering later this week, so I’m very interested in any failures from the field.

    • I’m with you… I like the WAGO and clones for temporary/test hookup stuff, but solder everything to stay in the RV. Too much shaking to trust nuts or spring clamps imho.

      • But cold solder joints can be just as bad. Back in the ’80s I worked for a company that had one of their R2R ladders for the D/A steering control of a Polaris missile fail due to a cold solder joint. So an armed nuclear missile went out of control and the range officer had to blow it up mid-flight. That’s why I worry so much about cold solder joints. (No kidding!!!)

  8. Your statement, “source of overheating” … “possible fire inside the walls” confuses me.

    I was under the impression that: 1) connections can only be made inside a box and 2) boxes cannot be hidden/must be accessible.

    Am I missing something?

    • Yes, you are correct that the NEC does require that all splices be made inside of a box, and all boxes must be accessible. However, I have seen a LOT of RVs where splices are NOT inside of a box, especially for 12-volt DC circuits. And 12-volt DC circuits can be just as dangerous as 120-volt AC.

      • Have you done resistive heating tests on these yet? I’m concerned by the actual conductor-contact area of anything spring-based.

        • I now have a pile of these things, so that would be a pretty simple test. Let me see what I can come up with. A side-by-side comparison of a WAGO and terminal connection with an infrared FLIR camera would show a lot.

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