Electrical connection question

[SWTobias]

I was working on my Larson 215 Hampton, Volvo-Penta 5.0GL with an SX drive this weekend and am having some difficulty with electrical connections.

I was wondering what boat owners consider a good product to use on electrical connections both to clean them and provide good contact. I've personally used die-electric grease which seems relatively good. I?ve also sprayed WD-40 ?over? connections but not completely covered the connection prior to connecting it. It seems that would actually prevent a good connection.

I have a number of connections that, when tested with a meter, are not getting a good 12 volts through them. Some of the connections I can?t get to so that I can clean them (such as ?pin? connectors). On all the ones I can get to, I?m using a dremmel tool with the rotary wire wheel, or a file, to clean them prior to reconnecting them (and applying die-electric grease). I would like to use some sort of cleaner/corrosion protector/electrical connection contact material on all of these to extend the period of time before the connection(s) fail again and maybe to get a better connection on the ones I can?t clean.

I spent all day Sunday trying to trace down a low-voltage problem preventing my horn from working, instead of being out on the water :facepalm:. I can only get about 3 volts from the point of connection to the horn-button so I guess somewhere else down the line there?s a bad connection. I traced down and located several other bad connections and after thoroughly cleaning them I got some parts working again that had also failed (factory installed depth finder).

Thanks,
Steve T.

 

[seabob4]

Re: Electrical connection question

You need to check the condition of your wiring as well. Assuming your boat is 10+ years old, you'll see the dreaded black in the wires themselves. Big time resistance, as well as voltage drop over runs...

 

[jhebert]

Re: Electrical connection question

I've personally used die-electric grease which seems relatively good.

Dielectric grease is an insulator. It should not be used on electrical contacts. It does not improve conductivity. Its use on electrical connectors is to create an electrically insulating seal around the connectors to keep out water and moisture.

WD-40 is a reasonably safe spray to use to clean and restore electrical contacts. There are other products which may be better, but WD-40 is easy to find and works acceptably well with low-voltage electrical components to help restore contacts.

Be very careful using coarse abrasives on electrical contacts. I prefer to use very fine emery cloth and wet sand with WD-40. Use 600-grit abrasive. Never take a wire brush to electrical contacts.

 

[SWTobias]

Re: Electrical connection question

Thanks for the info on that. I honestly thought that dielectric grease was supposed to be used on the contacts themselves. I realized later that I was actually causing a poor connection by using it on the contact itself. I'll definitely change my way of using that, and only use on the outside surface to (help) prevent corrosion.

I did another search of the forum and found some references to 'Deoxit', an electrical connection cleaner/contact enhancer. From what I can read, it looks pretty good, maybe better than WD-40 but I have no experience with it. Does anyone have experience using this product on marine applications

I'm curious about the recommendation to not use a wire brush on the electrical connections. Will that cause further damage? I have used a fine sandpaper before and will go back to that.

I also want to thank the reply regarding the wiring itself. The boat is a 1998, so definitely over 10 years old. I noticed on a couple of the wires I replaced that about an 8th of an inch or so inside the rubber sheathing was discolored (blackish-green). Whenever I see this I cut off that section and attach a new connector. I wonder how far back the corrosion actually goes?

Thanks again,
Steve

 

[Woodnaut]

Re: Electrical connection question

While it is true that dielectric grease is an insulator, it also will prevent corrosion and exclude moisture. For salt water applications, it can and should be used on terminals and contacts for this exact purpose. I work for a global company that has an extensive base of offshore instrumentation. The use of silicon based products on contacts and terminals is essential to keep instrumentation systems working offshore. It also ensures that connectors can be disassembled after they've been in service for a while. We have over 200 Electronic Technicians worldwide maintaining equipment in this fashion.

The presence of the dielectric grease on a ring terminal that is screwed onto a terminal block, for example, will in no way degrade the signal quality nor impede the current flow. As noted, it will prevent corrosion that will eventually lead to an open circuit. It can be used on battery terminals and cables - before mechanically connecting them - to prevent corrosion as well. I've been doing it for years with excellent results.

Some of the problems you might be having might be related to corrosion inside of the crimp terminals that are on the end of the wires. If marine grade wire is not used (tinned wire) corrosion can easily occur. The terminals on the end of the wire can be easily replaced, but again, make sure the wire is coated with silicon grease, insert it into the terminal, and then crimp. The final connection between the terminal and whatever it is that you are connecting it to should also be lightly coated with silicon grease. Don't overdo it and make a mess. A light coating is all that is required. But just to be clear on this, the silicon grease goes on the metal parts before they are assembled - not after. This prevents corrosion between the mating surfaces which can lead to a poor connection.

I built my boat 11 years ago which includes the entire electrical system. I followed theses techniques and after all these years of use in salt water I've never had a terminal failure. Also, I do not recommend the use of WD-40 for this application. Take a look at a product called Corrosion X.

 

[SWTobias]

Re: Electrical connection question

Thank you for an excellent explanation, just what I needed. It looks like my application of the dielectric grease directly to the contacts was not 'directly' responsible for the poor connection(s). Although, I may have put too much on them. There was powdery type buildup on the contact points I disassembled, which I removed.

I think I've heard of Corrosion X. I'm heading to Radio Shack this evening to look at their products, I understand they carry the Deoxyit and perhaps they'll have the Corrosion X.

Thanks again to everyone