Since I got my boat, I have been bothered by the fact that the engine will not start in the way it is described in the manual unless plugged into shore power. The manual says to hold the glow plug button for about 30 seconds and then while continuing to hold that button in, push the start button. When I do that, the starter does not turn over. If I release the glow plug button and push the start button the engine starts fine. My father (retired electrical engineer) and I (genetic engineer- useless in this case but sounds good) spent some time trying to diagnose the problem this weekend and found two interesting things:
1. The buttons both tested fine in terms of their switch function. We then tested power at the engine. There is a heavy red cable coming from the battery to the starter measured 12V. The red-yellow wire from the start button is attached to what I am presuming is the solenoid (the wiring diagram in the manual does not show a solenoid). We only measured 8 volts at the solenoid when the button is pushed, but 12 volts everywhere else. So that probably explains the fact that both the glow plugs and starter won’t work at the same time because we appear to be losing 4 volts in the solenoid. I will pull the starter next winter and have someone test it unless someone has an alternative suggestion. 2. The wiring diagram in the manual (Fig 2 on page 13) shows the power from the key switch coming into the glow plug button and then a wire from the other lead to the start button. The manual shows that wire running from the downstream side of the glow plug switch so that the start button should only be energized when the glow plug button is pushed (as the manual describes). If that were the case, the I would not be able to start the engine with only the start button. Nevertheless, it does start the engine. Tracing the wires, we found that the bridging wire actually came from the hot side of the glow plug switch, so that either button will work independently as both are always powered. What I don’t understand is why you would wire it the other way (as the manual shows) since that would remove the ability to start the engine without the glow plugs (as in an already warm engine). I don’t know if the PO or some yard mechanic made that change or if it is indicated wrong in the manual, so I am curious how other Universal panels are wired. The way it is actually wired makes more sense to me than what is in the manual unless I am missing something. Thanks- Dave Aries 1990 C&C 34+ New London, CT
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