General Electrical Connection/Contact Cleaning?

MrJim · Jul 21, 2015

Looking for some tips and advice on cleaning corroded electrical connections/contacts on my new-to-me boat. I noticed that several connections have some corrosion on them, particularly in the engine room/bilge area. I'm hoping to systematically disconnect, clean, and reconnect as many of these as possible in the hopes of solving some electrical issues as well as heading off future problems. Does this seem like a reasonable approach to you? What do you recommend for a procedure, what types of cleaners and protectant should I use (e.g., should I spray some Boeshield on the connectors after I re-connect them)?

My batteries are 4 years old, but are still in warranty (84 months) and seem to be holding a charge. I'm pretty set on replacing them anyway, but would I just be wasting my money? The surveyor recommended replacing them, but I don't know why, other than that they were "old."

This all came to a head last week after my boat wouldn't start after a full day at the beach with a boatload of out of town family visitors. Also, my tachometer has been unreliable and, for some inexplicable reason, my cabin top lights won't stay on. All of these are electrical issues, and I'm sure there will be others if I don't take some aggressive preventive maintenance action.

Any advice is welcome. After last week, I don't trust this boat any more. I want to be able to trust it again. Thanks!

MYTraveler · Jul 21, 2015

If the connectors are corroded, the wires may be too. If so, they need to be replaced. Pics would help.

FF · Jul 21, 2015

The finishing touch is to add bronze washers .

Copper is best ,,,SS is NEVER!

Washer, Star Lock, Internal Tooth, Phosphor-Bronze

www.bandc.biz › Electrical Supplies › Circuit Protective Devices

Use these washers under the heads of circuit breaker screw terminals to produce and maintain a good electrical contact with the bus.

BlueYonder · Jul 21, 2015

Lots of products out there. I have been using Corrosion X for several years and have been happy with the results.

CorrosionX

caltexflanc · Jul 21, 2015

You are usually better served putting on new heat shrink connectors rather than cleaning old crudded up ones. As Traveler noted, the corrosion often goes up the line a bit. You can clean up the posts and their bases with some distilled white vinegar and a stiff bronze or plastic brush. After remediation and reconnection, I too recommend Corrosion X, great stuff.

Xsbank · Jul 21, 2015

Don't forget dielectric grease?

caltexflanc · Jul 21, 2015

Xsbank said:
Don't forget dielectric grease?

Corrosion X does the same job, better in my opinion based on experience with some large battery banks in particular.

Xsbank · Jul 21, 2015

Use the spooge of choice, some used to use petroleum jelly. Just use something, not dry.

Aircraft mechanics use dielectric grease, which is how I learnt of it. It has a pretty good record.

MrJim · Jul 22, 2015

MYTraveler said:
If the connectors are corroded, the wires may be too. If so, they need to be replaced. Pics would help.

That's a sobering thought. Maybe a stupid question, but how does one trace a wire when it disappears into a wire bundle which passes through a bulkhead into inaccessible areas? There are many times when I'm in the engine room and say to myself "I wonder what this wire is."

Larry M · Jul 22, 2015

MrJim said:
That's a sobering thought. Maybe a stupid question, but how does one trace a wire when it disappears into a wire bundle which passes through a bulkhead into inaccessible areas? There are many times when I'm in the engine room and say to myself "I wonder what this wire is."

You boat should have a color coded wiring harness not just a bunch of red and black wires. Previous owners have been known to add a few personal touches to the wiring though.

ABYC has a set of recommendations for wire colors and purpose.

Marine Wire and Cable: Marine Wire Color Codes

Art · Jul 22, 2015

If batts hold charge and are correct size/type for usage they service... I advise keeping them till they get too bad off. What type and number of batts do you have? Also, seems that the dead batt you mentioned was due to visitors you also mentioned who may have misused items. I recommend keeping a new condition, always charged isolated batt on board, for emergency needs such as simply engine starting.

Tacks - Don't ever trust em to be fully accurate rpm reading.

Good luck in getting wire connections resuscitated into stable elect-flow condition.

Happy Boat-Stuff Daze! - Art

psneeld · Jul 22, 2015

for tracing wires...they have electronic sniffers where you attach a transmitter at the known source/destination then use receiver to check wires a they come out of a bundle/bulkhead to see what is what.

available at big box stores I think but better/more specialized ones can be had...

caltexflanc · Jul 22, 2015

A handy thing to have on a boat is some lengths of, say, 16 gauge, single cable with alligator clips on both ends. Surprising how many uses, one of which is attaching one end to the probe on a multimeter and the other to some distant spot you are trying to determine continuity or voltage that the probes won't, are awkward to, reach.

MYTraveler · Jul 22, 2015

MrJim said:
That's a sobering thought. Maybe a stupid question, but how does one trace a wire when it disappears into a wire bundle which passes through a bulkhead into inaccessible areas? There are many times when I'm in the engine room and say to myself "I wonder what this wire is."

Great ideas above about tracing strategies. Sometimes you can deduce the point of origin (a high-water alarm switch must be attached to the alarm) and conclude that the most expeditious approach is to run a new wire, possibly along a new path. In those circumstances the old wire is left in place with its ends cut off. If at all possible, remove that old wire, or as much of it as you can. If not possible (and I am not convinced that it is ever impossible), then at least label both ends.

MrJim · Jul 22, 2015

Art said:
If batts hold charge and are correct size/type for usage they service... I advise keeping them till they get too bad off. What type and number of batts do you have? Also, seems that the dead batt you mentioned was due to visitors you also mentioned who may have misused items. I recommend keeping a new condition, always charged isolated batt on board, for emergency needs such as simply engine starting.

Tacks - Don't ever trust em to be fully accurate rpm reading.

Good luck in getting wire connections resuscitated into stable elect-flow condition.

Happy Boat-Stuff Daze! - Art

I have two batteries that supply the house as well as engine/starting. There is a third battery in the engine room that is dedicated to (IIRC) the digital throttle control system. I have a booster battery pack that I usually take on board for emergency - just didn't have it that day, and I don't think the battery was the problem anyway.

I don't need my tach to be fully accurate, but this one just dies on me. After working fine initially, it slowly creeps down to zero. I was just thinking that maybe there's a poor connection somewhere.

Thanks for all your input everyone

MrJim · Jul 22, 2015

MYTraveler said:
In those circumstances the old wire is left in place with its ends cut off. If at all possible, remove that old wire, or as much of it as you can. If not possible (and I am not convinced that it is ever impossible), then at least label both ends.

Haven't done it yet, but I always figured that if I had to replace a wire, I could try to use the old wire to pull the new wire through the inaccessible areas into position. I guess it would depend on how tight the bundle or bulkhead penetrations are and whether there are any other obstructions. I've actually done this with speaker wires before.

SCOTTEDAVIS · Jul 29, 2015

Some tachs operate off the alternator output, perhaps the problems are related.

Capt.Bill11 · Jul 29, 2015

MYTraveler said:
If not possible (and I am not convinced that it is ever impossible)

You need to get out more.

Because trust me, on some boats, short of a chain saw or cutting torch, you are not removing all the old wiring.

FF · Jul 30, 2015

"I guess it would depend on how tight the bundle or bulkhead penetrations are and whether there are any other obstructions."

A single wire tie , and this dream fails.

TDunn · Jul 30, 2015

The first thing you want to do is rewire your batteries into two banks that are normally not connected. One bank should be for engine starting and the other for "house" operation. The two batteries should be connected in two ways. First by a battery combiner which connects the two banks when there is a charging voltage present (i.e., when you are underway). The second connection is via a 1-2-both stitch so that you can use all batteries for engine starting in a low start battery situation. With the house and starting batteries normally separated, you won't draw the starting bank down while the engine is shut off.

I am surprised that boats are built with a single "multi-purpose" battery bank.

Even my 1936 vintage cruiser has two separate battery banks. I have a group 31 starting battery for my 40 hp Volvo-Penta diesel and 3 group 31 house batteries. The two banks are connected by an interconnect switch, which I have only used during testing of the system, and a battery combiner relay rated for more than my 110 amp alternator output.

FF · Jul 31, 2015

3 group 31 house batteries.

Almost every GR 31 batt I have seen is a starting battery , where did you locate deep cycle batts in 31 size?

Art · Jul 31, 2015

FF said:
3 group 31 house batteries.

Almost every GR 31 batt I have seen is a starting battery , where did you locate deep cycle batts in 31 size?

I got my four house bank deep cycle 31's from Batteries Plus chain of stores. Good service and affordable too!

These 31's are manufactured by East Penn Batt Company. Seven years use and still going strong. They are termed as "maintenance free"... however, under the easily pealed back product sticker are well placed and gasket (O-ring) sealed individual screw-on cell openings. I check every six months and usually add a bit of distilled water once a year. IMO - the term "maintenance free" on wet-cell acid batts = pay no attention to fluid level and purchase new batts sooner! :whistling:

BlueYonder · Jul 31, 2015

FF said:
3 group 31 house batteries.

Almost every GR 31 batt I have seen is a starting battery , where did you locate deep cycle batts in 31 size?

Deka (East Penn), Trojan and Rolls make deep cycle group 31 batteries.

General Electrical Connection/Contact Cleaning?

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