Another mast wiring mystery!

[redpointist]

So I bought a 30 year old boat and none of the mast lights work...surprise! An obvious culprit was a corroded (not heat shrinked) crimp connection at the base of the mast. I fixed that connection and that got the strobe light working, but the anchor light and running lights are being stubborn.

There is a 6 wire quick disconnect there at the base of the mast. 3 ground wires from the mast go together into one of the six prongs and then back to the battery, and the other 5 prongs lead to individual wires. There are switches at the main panel for strobe (now working), mast anchor light, mast running light, and spreader lights, however the boat doesn't seem to have spreader lights installed. That leaves 3 of the individual wires having known uses, and 2 unknowns.

Im going to go up the mast in the next weekend or two and do some more recon, but something that confused me was a 7.6v reading from one of the individual wire prongs to the ground wire prong (EDIT: while I was playing with the battery side of the connector). Two of the other prongs read 12v, and two didn't have any voltage. TLDR: Could this 7.6v wire be the intended voltage for this wire, or could there be a short or something else causing the odd voltage? I haven't been able to trace the mast wire bundle all the way back to the switch panel yet, so I'm not sure where this 7.6v wire originates, or terminates for that matter. So confused!

[van demon]

Originally Posted by redpointist

So I bought a 30 year old boat and none of the mast lights work...surprise! An obvious culprit was a corroded (not heat shrinked) crimp connection at the base of the mast. I fixed that connection and that got the strobe light working, but the anchor light and running lights are being stubborn.

There is a 6 wire quick disconnect there at the base of the mast. 3 ground wires from the mast go together into one of the six prongs and then back to the battery, and the other 5 prongs lead to individual wires. There are switches at the main panel for strobe (now working), mast anchor light, mast running light, and spreader lights, however the boat doesn't seem to have spreader lights installed. That leaves 3 of the individual wires having known uses, and 2 unknowns.

Im going to go up the mast in the next weekend or two and do some more recon, but something that confused me was a 7.6v reading from one of the individual wire prongs to the ground wire prong. Two of the other prongs read 12v, and two didn't have any voltage. TLDR: Could this 7.6v wire be the intended voltage for this wire, or could there be a short or something else causing the odd voltage? I haven't been able to trace the mast wire bundle all the way back to the switch panel yet, so I'm not sure where this 7.6v wire originates, or terminates for that matter. So confused!

its a back feed or a poor neg connection

take the connector block apart and using a multi meter on resistance range read from each positive to the earth or n block ( the three wires twisted together) a low reading should inicate that something is connected ie a light a very high reading indicates nothing connected

now take a battery and connect each positive with a low reading to positive on the battery and the twisted negs to the neg post go outside and see whats working


if your not to sure with a multimeter this link is handy
http://splashurl.com/mt8mer2

[redpointist]

Thank you for the tip on checking the resistance on the mast side of the connector! I'll try that when I get to the boat this weekend. Im a total noob at performing electrical work so I wasn't quite sure where to start when I started on this.

I should add that the 7.6v reading was entirely on the battery side of the connector. One lead on the ground and one lead on another prong. The mast side was totally disconnected from this. I kept the lead on the same ground wire and switched the other lead to another prong on the same connector and got 12v.

[van demon]

Originally Posted by redpointist

Thank you for the tip on checking the resistance on the mast side of the connector! I'll try that when I get to the boat this weekend. Im a total noob at performing electrical work so I wasn't quite sure where to start when I started on this.

I should add that the 7.6v reading was entirely on the battery side of the connector. One lead on the ground and one lead on another prong. The mast side was totally disconnected from this. I kept the lead on the same ground wire and switched the other lead to another prong on the same connector and got 12v.

it usually makes more sense to do a simple line drawing and trace it out

the attached drawing it was i understand from your explanation

[van demon]

Originally Posted by van demon

it usually makes more sense to do a simple line drawing and trace it out

the attached drawing it was i understand from your explanation

picture

[bletso]

It really does sound like a corrosion problem giving a resistive load on the lead reading low. From where you are monitoring the voltage it could be at the terminal connector from the switch, or the switch itself. Not uncommon.

As you are checking it. before the connector the next step back would probably be a terminal block and then the switch. BTW, a short to cause that voltage drop would probably cause a fire or at least melt some insulation.

[redpointist]

So I made it out to the boat today. I checked the resistance on the wires going up the mast at the base. The one that works measured 2.3 K ohms...does this mean kilo ohms, hence 2300 ohms? From what I read it should be like 10 ohms so that seems odd. Could a strobe light work with a resistance that high?

The ones that dont work measured between 5 and 10 M ohms, which would be 2300000 ohms? The wire from the spreader lights switch was infinite resistance, and since there arent any spreader lights installed, that made sense at least.

I priced tinned copper wire and found 500' for $70 so its not as expensive as I thought. Maybe I'll just replace all the wire. My thrifty side does want to go up the mast and see if I can just clean the wire terminals or something, but for $70 it might be worth going ahead replacing the old wire since its of unknown age and origin.

[JPA Cate]

A suggestion from a cheap as you've never met before person: Clean each and every connection all the way, masthead to control panel; then check your voltages again. Supposing there's already tinned wire in there, actually, the wire may be okay. In terms of metals longevity, 30 yrs. isn't all that long. If it doesn't work, then replace it. Why spend money you don't have to? Let it prove it needs replacing. IMO.

Ann

[redpointist]

Originally Posted by Ann T. Cate

A suggestion from a cheap as you've never met before person: Clean each and every connection all the way, masthead to control panel; then check your voltages again. Supposing there's already tinned wire in there, actually, the wire may be okay. In terms of metals longevity, 30 yrs. isn't all that long. If it doesn't work, then replace it. Why spend money you don't have to? Let it prove it needs replacing. IMO.

Ann

It doesn't look like any of the old wire in the mast is tinned. At the base of the mast the connections we pretty corroded from a leaky mast boot. The boat has been sitting in fresh water for at least the past 10 years or so so at least the bare copper hasnt been exposed to salt. I do plan on taking it to the gulf in a year or two though, so maybe its worth investing in new tinned wire? I'll probably try cleaning the old wire first even if I do end up replacing it regardless.

[bratzcpa]

A suggestion from a guy who re-built a 30+ year-old boat too. . . . JUST REPLACE ALL (100%) OF THE WIRING.

Sorry, didn't mean to shout. But it's just not not not worth trying to monkey around, trouble shoot and figure out what's wrong with the existing wiring.

Buy a new control panel with LED lights (indicating that they're on) and circuit breakers. And start there - -new wire to everything. Although its possible to piggy back off of existing wires, and share grounds, etc. . . . just say no. don't do it. New wires (ground and hot) to each device.

Here are a couple of inexpensive samples: \\//

If you try to cobble the old stuff, you'll be fighting and cussing it every step of the way. There are breaks in places you can't even seen. corrosion in wires that look good. Bad connections and don't look bad.

With a new control panel, you'll be able to see every single circuit, identify it, test it, troubleshoot it, and replace it (if necessary).

Also, as long as you're going to be running wires in the mast, run an extra (spare) set of wires up to the masthead too. Seal the ends off and label it. That way if you ever have something at the mast head go bad (chafing inside the mast or whatever), you easily solve the problem without having to pull the whole rig.

Seriously. start over 100% and you'll never regret it.

~markb

[Roy M]

Having just finished re-stepping and overhauling a 25 year old mast for someone, may I suggest you save yourself a lot of time and money and potential tragedies and go to a yard and have the mast removed for a complete overhaul. It generally costs about $500 for the down and up. Having the mast sitting horizontally on sawhorses allows you to inspect each and every fastener, pop-rivet and hardware item on the stick. It allows you to remove and replace the compression tubes and bolts holding the shrouds to the mast. It allows you to remove and lubricate (or even replace with ball-bearings) the halyard sheaves. With the mast down you can take the halyards to the laundry, wash them and rinse with fabric softener, restoring their finish and handling characteristics. You can replace EVERY INCH of electrical wiring, add an additional electrical conduit to reduce crowding , add a radar, hailer speaker (so you can have automatic fog signals, etc.), LED steaming and masthead navigation/anchor/strobe lights, wind instruments, spinnaker blocks, etc. You can even remove the sail track, paint the mast with linear polyurethane paint and make it like new, then replace all the sail track pop-rivets, even install a StrongLuff system to make the mainsail move easier. Or, you can shine it on and let the insurance cover it when something awful happens. Nothing lasts for thirty years in pristine condition.