M3-20 Universal - Gauges flicker, power drops and engine stops

[amandak]

Hi there,

I have a 1996 Catalina 28 with an M3-20 Universal engine. If anyone has a moment I would so appreciate any thoughts or feedback on my issue. Even just to give me a place to start from.

Basics: I have a full tank of diesel, fuel has been tested for water (none). I have an electric fuel pump. Primary and secondary fuel filters are new.

My engine starts fine. Once I am underway my boat stays running for about 15 minutes. At approximately the 10 minute mark my battery gauge starts flickering like crazy, my RPM, temperature and fuel gauges also begin to wobble (but not as much as the battery gauge). From that point I have about 5 minutes before my engine shuts right off (I assume cause the fuel pump has no power as well?). Once the engine has shut off there is zero power period. Engine won't restart, won't even turn over... oil light doesn't come on when I turn the key - all is totally dead. When I check the batteries they are fully charged and working fine. With a voltmeter I have tested the batteries, all of the connections, the battery switch, the solenoid - I even removed the wheel and tested all of the connections to the gauges themselves - all are getting full power. Weird thing is if I leave the boat overnight it will start again in the morning with no problem, but I'll have the same issues over again.

I am thinking this must be some kind of electrical problem b/c of the gauges going nuts... is that a logical assumption?

Any thoughts would be great appreciated!

Thanks,

Amanda

[GordMay]

Greetings and welcome aboard the CF, Amanda.
Yes, definitely an "electrical" problem. Good luck chasing the gremlins.

[amandak]

I have had a good night's sleep and it's all I thought about! My thoughts have led me to think it might be a bad ignition switch? I am going to test that today.

[ValiantV]

Almost sounds heat related...

[Tx J]

Originally Posted by amandak

Hi there,

I have a 1996 Catalina 28 with an M3-20 Universal engine. If anyone has a moment I would so appreciate any thoughts or feedback on my issue. Even just to give me a place to start from.

Basics: I have a full tank of diesel, fuel has been tested for water (none). I have an electric fuel pump. Primary and secondary fuel filters are new.

My engine starts fine. Once I am underway my boat stays running for about 15 minutes. At approximately the 10 minute mark my battery gauge starts flickering like crazy, my RPM, temperature and fuel gauges also begin to wobble (but not as much as the battery gauge). From that point I have about 5 minutes before my engine shuts right off (I assume cause the fuel pump has no power as well?). Once the engine has shut off there is zero power period. Engine won't restart, won't even turn over... oil light doesn't come on when I turn the key - all is totally dead. When I check the batteries they are fully charged and working fine. With a voltmeter I have tested the batteries, all of the connections, the battery switch, the solenoid - I even removed the wheel and tested all of the connections to the gauges themselves - all are getting full power. Weird thing is if I leave the boat overnight it will start again in the morning with no problem, but I'll have the same issues over again.

I am thinking this must be some kind of electrical problem b/c of the gauges going nuts... is that a logical assumption?

Any thoughts would be great appreciated!

Thanks,

Amanda

Almost certainly a heat-related electrical problem. A connection or component somewhere is going partially to fully open (or shorted) under heat and/or vibration stress.
It could well be a major ground connection, like the battery bank grounding cable on the engine.
Might be good to disconnect all non-essential devices (chartplotters, solar chargers, etc), then do a test run first, problem could be a parasitic load device problem too.

Then I would disconnect the batteries (for safety), and work through all the electrical connections accessible, big and small, one or two at a time (battery and ground cable conns in particular). Very carefully, you don't want to break anything else. Do multi-connection connectors too (likely smaller gauge wires) by opening them, cleaning terminals (CRC makes some good spray electrical cleaning stuff) with Q-Tips or whatever, and applying No-Ox or dielectric anti-corrosion grease.

Process would be undoing a connection (terminals or whatever), both battery feeds and grounds, thoroughly cleaning (w/CRC stuff or ?) and adding No-Ox anti-corrosion 'grease' (or equivalent) to that connection. While at the same time carefully inspecting the cables/wires at the connection, for corrosion or heat damage too, then making repairs/replacements as needed, and remaking the connection. Then move on to the next cable/wire connection.
As you go through these circuits, you could also draw a schematic (connection) drawing for future reference.

No point in retesting anything until you're done with all the connection cleaning/remaking process.

When you've done all possible connections, reconnect the batteries (you did clean and anti-corrosion them too, right?), and then start the engine and wait the 15 minutes or so.
The probability is high that the trouble will be gone. And your whole electrical systems connections should be good for some time (in some cases, you might have needed to replace a severely corroded cable/wire, as found above).

If this should not work, you possibly have a defective (internally) component, such as the alternator or starter.

Don't worry about all that prior anti-corrosion connection effort, it will payoff irregardless.

Then it's time to test such components (starter-alternator/etc) per standard procedures, and/or just remove them and take to an auto parts store and have them do a thorough testing (usually no charge).

If this fails, then do you have things like an external regulator (Sterling,
Balmar MC614, etc) that may have failed?

This overall 'plan' is designed for a minimally technically competent repairer process, as most people would be; from simplest step (cleaning contact points) to more complex (component tests).

[Stu Jackson]

Bad ground at the engine. Remove and clean. Visual inspection is not adequate. Remove & clean.

Also check power to instruments when energized (seems like you may have done this - there's a loose connection from your power source to the entire panel --0-0 bad fuseholder?).

[amandak]

Hi Stu Jackson and Tx J, thank you for taking the time to respond!

I will remove & clean all connections today - good plan!

All power to instruments is solid and all work fine. The relay fuse in the control panel is also in good shape. I have tested the power to/from my control panel as well as to the pedestal (all gauges are in a box attached to the pedestal in the cockpit) and they all have loads of power coming to them.

Tried to start the boat this morning and zero happens when I turn the ignition switch. Gauges lay dormant and no oil light comes on.

Will get cleaning!!

Amanda

[amandak]

Hi Stu Jackson and Tx J, thank you for taking the time to respond!

I will remove & clean all connections today - good plan!

All power to instruments is solid and all work fine. The relay fuse in the control panel is also in good shape. I have tested the power to/from my control panel as well as to the pedestal (all gauges are in a box attached to the pedestal in the cockpit) and they all have loads of power coming to them.

Tried to start the boat this morning and zero happens when I turn the ignition switch. Gauges lay dormant and no oil light comes on.

Will get cleaning!!

Amanda

[Tx J]

One more thought: Are you sure that your battery (ies) are good?
A battery with a weak internal connection or various faults can sometimes act up with similar symptoms. Even if a fairly new one (better, as you might still get a warranty adjustment).
It's a hassle, but an auto parts place, or even a Walmart, can do a simple battery load test on them for you (let it sit in the sun for a while first to heat up ;] .
Of course, you can 'tap' it a little with a rubber hammer too, while running as before :[ (have a fire extinguisher handy...).
And cleaning/reterminating most all electrical connections boat-wide might as well be considered a routine maintenance chore (every two years or so), in any marine environment.

[capt jgw]

Universals are notorious for their lousy wiring harnesses. Does yours still have the "trailer plugs"? Black or white rubber connectors in the harness, they look like the connectors used for trailer lights. One at the panel and another at the engine. They were used to make installation plug and play rather than having to run individual wires between the engine and panel. They will heat up and open or short and have caused many fires. If you still have them, cut them out and splice the wires directly with heat shrink butt connectors. You can eliminate any excess length in the wires at the same time, which will also help. Related to this, do you still have the amp meter in the panel? It is the cause of the plugs heating up. Full alternator output goes through the heavy orange and red wires to the meter, and neither the wires or connectors can handle that much current. The fix is to connect the alt output directly to the starter Positive lug using heavy cable, as short as possible, eliminating the amp meter. You can replace the amp meter with a volt meter which only needs a small gauge pos/neg connection at the panel.

[Stu Jackson]

Originally Posted by amandak

>>>>>>>>>>>>>>>> and they all have loads of power coming to them.

Tried to start the boat this morning and zero happens when I turn the ignition switch. Gauges lay dormant and no oil light comes on.

Will get cleaning!!

Amanda

Fuseholder in the line from the iignition switch, usually cleverly hidden under the alternator; follow the wire OUT from the starter solenoid. Check for that first. Then jumper your ignition switch to assure that end is OK.

I usually say it's rarely the switch, but I had to replace mine in May. 30 years? No too bad.

Good luck.

PS - You might be interested in this:


Critical Upgrades CRITICAL UPGRADES - DO THESE OR ELSE!!!

[David M]

Clean, coat and tighten all of your grounds especially your larger grounds. Lights flickering that use different positive sources and return back to a ground in common is a sign of a bad ground.

[boeing1]

Yes, good place to check is the disconnect plug for the engine harness, I have seen several that had corrosion.

[amandak]

Thank Stu. I read somewhere else there was a fuse there... I dug around yesterday, but couldn't see it. I will check again! Thanks. I scrubbed all battery connectors yesterday, but they looked pretty good - I cleaned them in 2015 so weren't too bad. Will keep you posted!

[amandak]

Thanks TX j. Well not totally sure about batteries. They seem to functioning alright. I'll try and strike off a couple of other things first. I cleaned all battery connections in 2015 so they looked very good - I still did it again yesterday - made no difference unfortunately. thanks!!