CONTINUOUSWAVE

Please help me understand the electrical wiring on my 2002 170 MONTAUK that has a non-working Perko old-style-with-chocks [combined red-green sidelights lamp at the] bow.

The lamp has a black wire and a white wire. The lightbulb is the Festoon style, and I have installed a new one.

TEST PROCEDURE and TEST RESULTS

Test light with ground directly to battery negative post shows both black and white wires and connections to bulb light up.

[At the console dashboard the switch for NAV LTS] works in all positions.

White and black wires are in the light, black and gray wires come out of the boat.

frontier wrote:Test light with ground directly to battery negative post shows both black and white wires and connections to bulb light up.

I don’t understand your test circuit. Please give a clearer explanation.

frontier wrote:[At the console dashboard the switch for NAV LTS] works in all positions.

Again, your report of the test results is hard for me to understand.

Navigation Lamp Control Wiring on Boston Whaler 170 MONTAUK

The typical arrangement on a newer Boston Whaler is to control the navigation lamps with one switch. The switch is usually a rocker switch, and the switch typically has three positions.

One position is usually identified as ANCHOR or perhaps ANC, which should only illuminate the white all-round light lamp, which is necessary to show when the boat is not underway and is at anchor.

The second position is for underway operation, which should illuminate the combined sidelights lamp at the bow AND the white all-round light lamp at the stern, typically mounted on a pole. The switch legend used to identify that switch position is often NAV (as in navigating). This is the necessary lighting to show when the boat is in motion or UNDERWAY.

The third position is both lamps not illuminated or OFF.

The details of the switch wiring are very important. If someone replaced the control switch with the wrong part, there is no telling what unusual behavior might result with regard to when and which lamps are illuminated or dark in what switch position.

In regard to a 2002 170 MONTAUK 17, Boston Whaler has provided a very detailed schematic diagram of all the wiring on the boat, including the wiring of the navigation lighting circuit.

I don't know if the detailed diagram is included in the owner's manual, but the diagram is available from Boston Whaler on their website. For help in locating the diagram (and other resources related to a particular year and model boat) see the advice given in the forum THE GAM at:

How to find Original Boston Whaler Diagrams and Drawings
https://continuouswave.com/forum/viewtopic.php?f=4&t=9897

In the case of the electrical schematic drawing for a 2002 170 MONTAUK, the beautifully detailed drawing can be found at this URL:

WIRING DIAGRAM 170MT-02
https://www.bostonwhaler.com/content/dam/boston-whaler/technical/resources/170-Montauk-Wiring-Diagram-Assembly-2002.pdf

The combined sidelights lamp is connected to wire number 203, a 14 AWG conductor with GRAY insulation for the positive or switched circuit. This is indicated on the drawing as "203-14 GRY".

The other conductor from the combined sidelights lamp is connected to a wire number 204, also a 14 AWG conductor with BLACK insulation for the unswitched or negative circuit. This is indicated on the drawing as "204-14 BLK".

The positive conductors are connected to the +12-Volt power distribution, typically with fuse protection for each circuit.

The black conductors are connected to the negative bus bar at the console, which in turn connects to the negative post of the battery.

The gray conductor is connected to switch contact "3". This circuit is also used to power the COMPASS light, which seems sensible, as if the boat is underway the compass should also be illuminated. That circuit is carried on wire 207-14 BLU.

The gray-white conductor is connected to switch contact "2". This circuit carries power to the WHITE ALL-ROUND lamp via wire 205-14 GRY/WHT.

The wiring at the switch is rather clever. If you study the action of the switch, you will see how the three lamps (COMPASS, SIDEIGHTS, WHITE ALL ROUND) are controlled.

SWITCH DETAILS
Multi-position electrical switches can be very complicated and have very specific switch actions, which is to say, not all switches are exactly the same. The switch used by Boston Whaler in the OEM build of the boat was a specific model with specific action at the contacts.

A good first step will be to carefully inspect the wiring at the switch. Verify that the six conductors that connect to the various contacts on the switch are all in the correct locations. Below is an excerpt from the drawing which is labeled DETAIL 1 and shows the connections to the switch that controls the three lamps involved.

I have explained in more detail how the switch that controls navigation lighting works in an earlier article on that topic. That article gives even more details and information. I recommend you study that article to best understand how the switch and its wiring works. As I mentioned, the wiring is very clever. See

Navigation Lamp Circuits Used on Newer Boston Whaler Boats
https://continuouswave.com/forum/viewto ... f=9&t=4136

The above article has been viewed more than 10,000 times, which suggests its information content has been found to be useful.

Note that the switch being used is very likely a special-order configuration used by Boston Whaler, and to obtain an exact replacement switch from a retail source may be difficult (to impossible).

Thanks Jim for all the information - I appreciate it.

Last test I did before posting: Hooked up [the combined sidelights lamp] with only with gray wire attached from boat and ran a test wire from [the] black wire from boat directly to the negative post on the battery. The lamp worked like a charm using the dashboard switch.

CORRECTION: black wire on [on the combined sidelights LAMP was connected] directly to negative post on battery. And [the combined sidelights lamp] worked using dash switch.

Based on your new report of your test procedure and results, the most reasonable inference that can be made is that the cause of the combined sidelights lamp failure to illuminate is from an open circuit in the negative wiring.

I recommend you locate the wire 204-14 BLK. This wire runs from the "main ground bus" (which is probably inside the console) to the bow area, where it connects to a wire (probably the black wire) from the lamp socket in the combined sidelights lamp housing. Make a very careful visual inspection of the wire, looking to see if it has been damaged or cut in any way. Also check the screw terminal thats hold the wire end terminal fitting onto the negative bus. If there is any corrosion or if the screw is loose, that could also cause a block in the current flowing on that circuit. And check the connection between the wire and the wire-end terminal fitting, too.

At some point there is probably an in-line butt splice between wire 204-14 BLK and the black wire from the lamp assembly which will be under the lamp at the bow. That is also another possible point of failure. If water got into the recess in the hull where the wiring is kept, the water would rapidly corrode the copper wire.

Note that in low-voltage circuits like a 12-Volt DC, the flow of electricity can be stopped by a very small layer of non-conductive material. So a connection that visually looks like it is a proper connection may, in fact for a 12-Volt circuit, be no connection at all. Using the product WD40 and spraying it onto electrical connections can often restore the connection it the fault is just a thin layer of corrosion, at least temporarily.

If you find the in-line butt connector is the problem, replace it and get one with heat shrink sealing and internal sealant included. Be very careful in cutting out the existing butt connector and stripping the wiring, as there probably is not much extra slack wire available for re-doing that connector.

The reason for the unusual contact arrangement for the three-position rocker switch is the desire to have the switch action be:

• OFF
• ON-1
• ON-1, ON-2

instead of the more common arrangement

• ON-1
• OFF
• ON-1, ON-2

where ON-1 is the white all-round lamp circuit and ON-2 is the sidelights lamp and compass lamp circuits.

Also, the switch has internal illumination, which is then configured to show the switch as illuminated whenever the ON-1 circuit is energized.

Regarding the lamp wiring using BLACK and WHITE conductors:

Because you are using an incandescent lightbulb, the polarity of the DC connection won't make any difference.

The black/white wire colors on the lamp are probably a hold over from AC wiring, were "line" was black and "neutral" was common.

If you replaced the light bulb with an LED substitute, you need to get the polarity correct or it may not illuminate. Since the Festoon socket is not polarized, just switch the position of the LED lightbulb in the socket to test for a polarity problem.

ANOTHER PROBLEM
With some of the light fixtures that Boston Whaler used for the combined sidelights lamp, getting a good connection to the lightbulb depended on there being downward pressure exerted onto the lightbulb upper contact, transmitted from the housing onto upper socket. Check for that being a problem.