Mysterious instrument panel symptoms

[Carter Brey]

I'm having difficulty with certain engine instruments. I'm at a loss to explain what I'm seeing.

First, some info: I have a 1982 Westerbeke 13 with about 650 hours on it. It has the full "Admiral" instrument panel, no idiot lights.

When I start the engine, I put the key in the ignition and turn it to the "on" position. The warning buzzer sounds. The volt meter comes to life and shows about 12.8 volts and the fuel gauge comes to life and shows "Full," which is correct. I then turn it past that position to "start" and the engine turns over and catches. It runs normally.

At this point, the fuel gauge and volt meter behave normally. The fuel gauge continues to show "Full" and the volt meter shows charging at about 14 volts.

The water temperature and oil pressure gauges, however, read zero-- they remain completely inert.

The tachometer does not work. It stopped working halfway through last season. The hour counter works normally.

With the engine still running, if I turn the key to "off," the water temperature gauge jumps to the end of the scale-- 230 degrees-- and the oil pressure gauge jumps to 25 lbs. Normal water temperature is 180 degrees and normal oil pressure is 50 lbs. Both these gauges worked normally last season. I rebuilt the raw water pump and there is plenty of water burping out the transom exhaust. No steam. The engine clearly is not overheating and the alarm does not sound.

Any thoughts? I've done my best to trace the wires and have found no bad connections. My buddy Henry did his best to test the back of the instruments with a multimeter and found current getting to them.

Many thanks in advance.

Carter Brey
S28 MkII #532
City Island, NY

[Oswego John]

Carter,

Here is some info that may help you with your gauge problems. Read down.

http://www.moyermarine.com/forums/archi ... t-375.html

http://www.mindspring.com/~houlihan/merc/oilpress.htm

Good luck,
O J

[darmoose]

oops, I didnt see that you already checked connections. still suspect conections or wiring though sound like a commen ground to me. I wiil think some more.

Darrell

[barfwinkle]

Morning Carter

I experienced something very similiar when my main ground wire that is bolted to the engine broke. It wasn't completely broken in to, but it was not making good contact.

Good luck and Fair Winds

[sharkbait]

Assuming that no one has removed and replaced the temp and oil pressure sensor then I would look closely at the engine ground connection. Still sounds like a common ground problem. You might want to check the temp and oil sensor to ensure that no teflon tape was used when they were installed. Those sensors must have a good ground to the engine block. You could remove each of those sensors, clean the treads and reinstall them. Remember no teflon tape.

[Carter Brey]

Thanks very much to you all for taking the time to offer these leads-- I'll scope out the ground wire situation today.

Carter

[Ben Thomas]

Carter, it is not a good idea to turn the key to the off position while the engine is running, I assume there is another way to stop the engine,
With the key in the off position with engine running the alternator is still pumping out amps, with no where to go. This may cause your tach to malfunction as it gets its impluse from the alternator. It may also cause the other instruments to malfunction, such as spiking high or low. The juice has to go somewhere.
I would check the alternator first to see if it is still functioning properly, it may be the source of the other problems. Then check sending units for the instruments.
Balmar makes an inline fuse specifcally for this that is mounted on the alternator.
Good luck and keep us posted.
Ben

[Carter Brey]

Guys, thanks a million. I ran a wire from the common ground post on the back of the tachometer to a piece of bare metal on the engine block, then started the engine. I knew even before the starter kicked in that I'd found the problem because I could hear the glow plugs click into action when I pressed the key in. I hadn't been hearing that. As soon as the engine fired up, all the gauges (including the tach) sprang to life and showed correct values. It had indeed been a bad ground connection.

Ben, not to worry. I think you're confusing the key switch with the battery switch. On the Westerbeke marine diesels of this vintage, the key switch, once the starter has been engaged and the spring returns the key to its "on" position, only delivers power to the gauges. The Perko 1-2-Both-Off battery switch is what you're thinking of, and I never touch that once the engine is running, for the reason you describe.

Best regards and fair winds,
Carter Brey
S28 MkII #532 Delphine
City Island, NY

[sharkbait]

Very glad you got it fixed!

[darmoose]

So.. Carter............

Very glad you got it fixed. So after you determined that it had been a ground problem all along, did you go back and find the bad ground connection or wire (or was it the wire off the back of the tach, which I guess you just replaced?) In other words, it wasn't an engine ground, or something like that?

Isn't it an enormous relief when you resolve a problem like that, it's almost like having a new boat!

Darrell

[Carter Brey]

So.. Carter............

Very glad you got it fixed. So after you determined that it had been a ground problem all along, did you go back and find the bad ground connection or wire (or was it the wire off the back of the tach, which I guess you just replaced?) In other words, it wasn't an engine ground, or something like that?

Isn't it an enormous relief when you resolve a problem like that, it's almost like having a new boat!

Darrell

Well, Darrell, this is a very interesting question. I did not replace the ground wire from the back of the tach-- it's a common ground and loops over to every other instrument. I simply connected an extra temporary wire to the ground stud on the tach (could have been any of the gauges) and taped the other end to some bare metal on the the valve cover on the engine. Once I saw that everything was working, I disconnected the temporary wire and the gauges continued to function normally. Not only that-- I turned the engine off, then on again, and the gauges still continued to work normally. I can't quite account for this except to say that completing the temporary ground connection "woke up" whatever was hardwired to begin with. My guess is a burst of current bridging some corrosion. Another possibility is that a minor fuel spill caused by changing filters before the first engine start of the season resulted in a temporary short circuit at an exposed connection.

I again spent two hours trying to find a loose or otherwise compromised ground wire, without success. It may be inside a length of the harness leading from the panel to the engine that's heavily wrapped in tape, and which I so far haven't had the courage to undo. At any rate, I ran out of time and had to leave the boat. I'll be continuing to look for the culprit in the future, but at least I know that if the problem recurs I can effect a quick fix. If I really cannot find a root cause (corroded or broken connection, &c), then I can always run a new ground wire from the ground stud on the back of any of the gauges to some handy point on the engine block.

Cordially,

Carter Brey
Cmdr, Coastal Raider Delphine, displacing four tonnes.

[John Vigor]

Carter Brey
Cmdr, Coastal Raider Delphine, displacing four tonnes.

Aaargh, what kind, me hearty? Nett or (more likely) gross?

John V.

[Cathy Monaghan]

Carter, it is not a good idea to turn the key to the off position while the engine is running, I assume there is another way to stop the engine,
With the key in the off position with engine running the alternator is still pumping out amps, with no where to go. This may cause your tach to malfunction as it gets its impluse from the alternator. It may also cause the other instruments to malfunction, such as spiking high or low. The juice has to go somewhere.
I would check the alternator first to see if it is still functioning properly, it may be the source of the other problems. Then check sending units for the instruments.
Balmar makes an inline fuse specifcally for this that is mounted on the alternator.
Good luck and keep us posted.
Ben

Hi Carter,

I don't know the exact setup on your boat, but we have a Westerbeke 21A with the Admiral panel (pictured at the bottom of page 1 here). Our engine instrument panel has two buttons in addition to the key. One button is for the glow plugs and the other is to start the engine. We also have an engine shutoff/kill switch which is located, on our boat, in the port lazarette. So, like Ben mentioned, we don't shut down the engine with the key.

Cathy
CD32 Realization, #3
Rahway, NJ
Raritan Bay

[Carter Brey]

The problem turned out to be the 8-pin connector for the main wiring harness from the engine to the instrument panel.

The previous owner, or his mechanic, had swathed it in layers of black electrical tape underneath which the connector had separated. The separation first occurred with the connector coming apart at an angle, with the green ground wire from the instrument panel disconnecting first. This resulted in non-functioning instruments, lift pump and glow plugs while the solenoid, starter, and other electrical functions on board continued normally.

It was only when the starter motor failed to turn over, without even a click from the solenoid, while the batteries were clearly fully charged and things such as cabin lights and the stereo worked fine, that it occurred to me to unwrap the main harness and have a look. Voilá. The entire connector had finally come apart. I pushed the connector back together, wrapped it with new tape, and the engine purrs contentedly once more, all instruments functioning normally.

The solution always seems banal in retrospect.

Of course, the total failure of the circuit to the ignition happened while I was several miles out from home, the wind had died, and I was due home to help my son study for an important science test. Hallelujah for my unlimited TowboatUS account.

Cathy, by the way, Sabre Yachts at the time my boat was manufactured used an unusual but effective instrument/ignition setup. The instruments (tachometer, oil pressure, water temperature, volt meter and fuel gauge) are placed in a row on the aft face of the bridge deck, from where they are easily visible to the helmsperson. The ignition switch, low oil pressure/overheating alarm, instrument light switch and bilge blower switch are all located inside the aft lazarette, easily accessible to the helmsperson but protected by the closed lazarette hatch. There is no separate ignition pushbutton; one simply pushes the key in (starting glow plugs) and then turns it all the way to the right to start. Once the starter engages, the key is released and returns to the "on" position. The engine can only be stopped by moving the throttle lever on the pedestal all the way aft.

Fair winds,

Carter Brey
Sabre 28 MkII #532 Delphine
City Island, NY

[Steve Laume]

When I rewired my engine harness the two sets of connectors went good bye.

I can see why it was originally done that way. The engine is wired and dropped in place. The panel is wired and installed. Then some guy plugs em together with those connectors and tapes the crap out of them. Quick and easy until 20 some years pass and the pins aren't what they used to be or there is a short buried under all that tape some where.

I ran all new wires directly from the panel to their various points of attachment on the engine. With the original set up all of the wiring went to a connector at the alternator and from there to were ever it needed to go, even if it meant back tracking.

The oil pressure sender wire went all the way from the panel through two connectors to the forward port side of the engine. From there it turned around and went back to the rear of the engine.

I now have about half the wire on that run and no connectors. Nothing is wrapped in rolls of electrical tape either.

Neat and simple in in wiring is good, Steve.