CONTINUOUSWAVE

[Moderator's note: this thread has been moved to the SMALL BOAT ELECTRICAL forum for discussion because the topic is clearly an electrical topic.]

Since I had [LENCO trim tabs] installed by a mechanic at a marina, all power to the helm console on my boat is occasionally lost, including power to the trim tabs.

Interestingly, the outboard engine has started every time [the helm console has lost electrical power].

Sometimes the entire console will be dead right at the engine start, with no power to the fuel gauges, the lamps, the chart plotter, and etc.

Other times [all electrically operated devices at the helm console] will all turn on as normal, and then die 10 seconds afterward.

Sometimes [the helm console will stay] totally dead [electrically] during the entire boat trip.

At other times [electrical power to the helm console will] come back during the [boat] ride back to the dock with no apparent explanation.

I took [the 2001 Dauntless 16 with 2001 Yamaha 90-HP two-stroke-power-cycle engine boat] back to the mechanic at the marina who installed [the new LENCOtrim tabs]. This mechanic seemed to be a knowledgeable guy.

The problem [with loss of electrical power to certain devices at the helm console] is inconsistent, but thankfully [the propulsion engine] started dead at the marina twice for [the mechanic who installed the LENCO trim tabs] so that he could see [the problem] with his own eyes.

The mechanic all the fuses and battery are good. The mechanic disconnected and reconnected everything. The mechanic started [the propulsion engine] 20 times without the [loss of electrical power at the helm console] reappearing.

I took back the boat, and--of course--[something referred to only as "it" which could mean the problem with loss of electrical power at the helm console or the propulsion engine] started again after I took [the boat] back on the water.

Q1: what could be causing [the loss of electrical power at the helm console]?

The mechanic said that he is out of ideas. The mechanic suggested replacing the [ignition] key switch, but I hate to replace [the ignition key switch] if it's not even causing the [problem].

Q2: have readers had any experience [in which the power to the helm console becomes intermittent after LENCO trim tabs have been installed]?

All suggestion will be greatly appreciated.

Your narrative describes an intermittent problem where power to the helm console is lost, generally associated with the propulsion engine operating.

The most reasonable inference from your narrative for the cause of the intermittent loss of power is a loose connection in the conductors that supply power to the helm console.

That the onset of this problem occurred after work was performed to install LENCO trim tabs which are controlled by an electrical circuit could be coincidental or there could be a causal relationship.

Without knowing anything about how the 12-Volt power from the boat's battery is distributed to the helm console and the several electrical loads at the console, to suggest a particular location to look into is impossible.

A good start to solving this problem will be to make a detailed and accurate schematic drawing of the power distribution to the helm console, showing the actual source of the power, and exactly how various electrical loads are connected to the power.

If EVERY electrical load at the helm console loses power simultaneously at the onset of the power loss, then the most reasonable conclusion is that the 12-Volt power circuit that feeds power to the helm console from the battery is the circuit that is being interrupted.

Regarding circuit connections in low-voltage power distribution, like 12-Volt DC power, and particularly when these circuits are used near water, the continuity of an electrical connection cannot be judged only on its visual appearance. With low voltage circuits a layer of oxidation may form that will block the flow of current in a low-voltage system, but the appearance of the connection will be normal.

The best time to investigate an intermittent problem of loss of power distribution is WHEN the problem exists. That is when the break in the connection will be most easily found. Read my advice on electrical diagnostic techniques in my article at

Electric Starting Circuits
https://continuouswave.com/whaler/refer ... Start.html

and read the section that begins under the sub-heading "Electrical Diagnostic Technique." Also read the section under the sub-heading "Connections."

ASIDE: your narrative describes the person who you are paying to assess and remedy this electrical problem as a "mechanic." Historically the nature of outboard engines and their problems was based on mechanical problems. Modern boats have more electrical circuits than traditional boats. Many "mechanics" are not particularly adept in the diagnosis of problems in electrical circuits.

Regarding the onset of the electrical problem occurring after the installation of LENCO trim tabs by a mechanic hired for that purpose: without knowing anything about the exact circuitry of the LENCO system, the only inference that can be made is that the LENCO system required electrical power to control the operation of the trim tabs and electrical power to actuate motors that that move the trim tabs. On that basis the only inference will be that certainly the installation of the LENCO trim tabs must have involved making changes to the existing electrical power distribution on the boat.

On that basis, careful inspection of all the new electrical circuitry installed related to the LENCO trim tabs will be a good place to begin to look for the cause of the problem of intermittent power loss to the helm console.

ThePetrel wrote:Interestingly, the outboard engine has started every time [the helm console has lost electrical power].

This observation is useful information. The inference drawn from this behavior is that the electrical circuits related to the engine and the operation of the engine cranking motor are not affected when the helm power is lost. This suggests that the cause of the loss of helm power is not located in the engine start circuit.

Jimh—Thank you for your input.

I'll review the reference that you hyperlinked, and I will keep troubleshooting [the cause of the intermittent loss of electrical power to the helm console].

If and when I track down the actual cause, I'll post an update.

I believe this mystery has been solved: [the cause of the loss of electrical power at the helm after installation of trim tabs] appears to be the actual ignition key switch.

[Recently] I twice lost power on the water; I jiggled the [ignition] key [switch], and both times the power came back on to the console and trim tabs.
[I concluded there] must be a worn or loose connection somewhere [in the ignition key switch circuit].

To finally find the cause required a lot of troubleshooting.

[Perhaps this update that reveals the cause of lost electrical power] may help others.

Q3: what actions have you taken to remedy the loss of electrical power to the helm console after you concluded the circuit fault was in the ignition key switch connections?

Just your assessment that the fault must be in the ignition switch circuit connections does not explain how the problem was actually remedied.

Either the onset of the loss of power to the helm console was unrelated to the installation of the tabs OR your installation was made in a non-typical fashion.

Please detail the cause in the ignition switch.