# Connecting different AWG wires?



## wmk0002 (Oct 17, 2016)

I am finally getting around to wiring up my Helix 5 fishfinder. The included power wire is 18 awg. All of the waterproof fuse holders I found that I like have 12 awg leads. I know solder and heat shrink tubing is the best way to go, however, is there a good method for splicing two wires with such a large size discrepancy with a butt style fitting? Would 12 awg butt splice fittings work if they were the kind that had solder inside of them? I will give soldering another try first, but my last few experiences with soldering car stereos have been bad.


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## KMixson (Oct 17, 2016)

Try tinning the 18 gauge wire before crimping in the splice.


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## TNtroller (Oct 17, 2016)

Google posi-lock connectors. They are a screw together type electrical connector that will handle your situation very well and with ease. I've been using them for several years now with no problems or issues at all.


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## wmk0002 (Oct 17, 2016)

TNtroller said:


> Google posi-lock connectors. They are a screw together type electrical connector that will handle your situation very well and with ease. I've been using them for several years now with no problems or issues at all.



I'm familiar with them. I used them on my last stereo in lieu of soldering and like them. Are they waterproof though? Can you seal them with silicone or still possibly use heat shrink?


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## mbweimar (Oct 17, 2016)

If I recall correctly, solder is a no-no in marine applications. I believe it has to do more with vibration than anything. That being said, I soldered several connections on my Weldbilt and had no issues in the 3 years I ran that boat. 

What I HAVE seen are called step down butt splices. They're non insulated, so obviously the beat solution would be to cover them with Heath shrink that has the adhesive sealant. 

A quick Google search of step down butt splices should get you going in the right direction.


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## DaleH (Oct 17, 2016)

*TIP* - Insert a small piece of wire to make up the difference ... just to make up the difference, i.e., grab 1" of 12 AWG wire (or whatever size), strip, cut off and twist around 18 AWG wire (or whatever size) and adjust to fit, pulling out strands of the wire you added. Don't need any insulated part, just the strands. Just be sure to enclose all in your adhesive-lined connector or under adhesive-lined heatshrink.

FWIW I do this all the time and have been wiring my boats for > 20-years and have yet to have a failure or even a blown fuse in any circuit I replaced myself!

*CAUTION to all about use of soldering ... on a boat!*

FYI, just so everyone is clear ... *soldering is typically NOT recommended on boats*, and in some cases - not even allowed - as per USCG, Mil-Spec, BIA, and/or ABYC standards. While it's use on board a vessel is frowned upon or even forbidden, it must NEVER be the sole means of connection for wiring. The reason for this is that soldered connections are BRITTLE and prone to failure when the wiring runs and/or connections shake, rattle, and jostle as the boat moves through the waves or trailers down the highway at 70mph! And if you had a fire ... and the insurance investigators found soldered connections ... you would lose your coverage in a second. But admittedly this probably applies more to boats for _charter or hire or rental. _

I personally never solder ANYWHERE on the boat ... and don't see any need to. Using marine-grade connections, a quality ratchet crimper, adhesive-lined heatshrink, and properly securing your wiring runs as per ABYC standards ... and I've never had a wiring issue. *Another tip*, for wiring used in the bilge or possible immersed in water, since I use butt-type (crimp) connectors, I also seal the end of the connections with 3M 5200 before sealing the wiring in the adhesive-lined heatshrink.

I post the above info as an FYI, not to debate the guys on this board who solder up their own connections for use on their tin boats. Some of you guys are awesome in your own technique - and I applaud that =D> - but I've seen way too many examples where applied techniques that may be appropriate in one arena or person, but may not be appropriate for another use or person - hence the caution. A tin boat and a 40' offshore _Go Fast_ boat are two entirely different uses :shock: and subject to tremendously different loading stresses!


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## overboard (Oct 17, 2016)

:lol: Just got done doing what you are asking about on a different project, and also recently did it with the 12 awg leads. 
What I usually do is strip the wire about twice as long as normal, and then double the wire back on itself to make it heavier so it will hold a crimp.
My process is to only use only the insert that's inside a plastic coated connector, I get that out by heating the plastic part and then pushing the inside crimp sleeve out with a nail or something similar. Then I crimp one wire onto it, slide a piece of shrink tube over either wire, crimp the other wire to the connector and then slide the shrink tube in place and heat it up. If it's an end just double up the wire and crimp, also can use shrink tube if desired.
I have also taken those crimp connectors for smaller gage wires and inserted them into a much larger gage connector to act as a reducer, first the larger connector has to be big enough to be able to insert it snugly, then I cut the small connector in half and clean up the cut ends by using a small drill bit, insert it into the large connector, and then crimp both together onto the wire, I normally only would use that for ends and not inline. 
When I did the fuse like you are talking about, the heavier wire went in single, and the lighter wire got doubled over, crimped, and shrink tube sealed.
There must be easier ways, but I've been doing splices like mentioned above for years and have yet to have a problem.
Might also add, I've also used the standard butt connectors as is, doubled over the wire/wires if needed, applied a sealant to the connector, inserted the wires and crimped, depending on where the splice is. Under dash I'm not as worried as exposed, but that's a good method also just not as nice looking!


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## crazymanme2 (Oct 17, 2016)

I have used a hot glue gun to waterproof my connections.


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## wmk0002 (Oct 18, 2016)

Thanks for all of the tips guys! Looks like I now have justification to steer clear from soldering which makes me happy lol. I like all of the ideas on thickening up the thinner wire to make it fit into a 12 awg connector. The mods to the butt connectors intrigues me as well. In the mean time, I may return that fuse holder I bought from Autozone and purchase one of the from Blue Sea Systems.

https://www.amazon.com/dp/B004ZIUA6...TF8&colid=3QSN8Q3H3W0FP&coliid=I2VWYVTKRO2LMC


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## KaiserSote (Oct 19, 2016)

I went with the blue seas fuse block https://www.bluesea.com/products/category/16/61/Fuse_Blocks/ST_Blade and like it a lot. Much easier to quickly access all of your fuses and a cleaner look in my opinion too. Ended up getting the 12 circuit with cover and negative bus. So far no complaints. If you are space limited they have dimensioned drawings on their site. Regarding the connectors and wiring I've bought both ancor marine wire and connectors and bestboatwire.com's stuff. Best was considerably cheaper and just as well made IMHO

Sent from my Nexus 6 using Tapatalk


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## wmk0002 (Oct 20, 2016)

KaiserSote said:


> I went with the blue seas fuse block https://www.bluesea.com/products/category/16/61/Fuse_Blocks/ST_Blade and like it a lot. Much easier to quickly access all of your fuses and a cleaner look in my opinion too. Ended up getting the 12 circuit with cover and negative bus. So far no complaints. If you are space limited they have dimensioned drawings on their site. Regarding the connectors and wiring I've bought both ancor marine wire and connectors and bestboatwire.com's stuff. Best was considerably cheaper and just as well made IMHO
> 
> Sent from my Nexus 6 using Tapatalk



I considered that, but opted not to go that route as I plan to install a switch panel into an electrical junction box forward of my rear deck/bench. I'm going to house all of my fuses there for everything the switch panel controls when I do that. 

I bought a Blue Sea dual bus bar to go near my battery which will accept the +/- leads for my trolling motor, fish finder, and the primary wires for the switch panel. I decided to wire the fish finder this way to avoid having to dedicate a switch to it so I'd have it free for something else. I'm not sure I explained that very clearly but maybe you get what I'm saying lol.


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## KaiserSote (Oct 20, 2016)

I follow you. If it's any help. They make much smaller fuse blocks that are essentially big as the bus bar

Sent from my Nexus 6 using Tapatalk


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## mrdrh99 (Oct 26, 2016)

I've only ever used butt splices, but I use 2 layers of heat shrink, and then wrap in electrical tape for strength. I've never had any problems


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