Electrical problems on diesel auxiliary

[jimd333]

I am unable to crank the starter on my 2 cylinder diesel from the start panel. I can jump the solenoid at the engine and the engine will crank. I've replaced the starter/solenoid and the start switch (on, crank, off) to no avail.
When I try to crank, I get nothing but the fuel guage pegs to empty (it rapidly flops over from full to the empty peg).
It sounds like a short (ground fault), I suspect it's in the start panel. Any ideas on how to proceed? Thanks.

[model 10]

When you say you can jump it, do you mean direct from the power lug to the lead that enters the starter housing, or from the power lug to the solenoid +?

[jimd333]

Power lug to spade connector which is connected to 16g red/yellow.

[pdbms]

You are possibly experiencing voltage drop. If the engine turns over when you short the solenoid terminal to the +ve lug on the starter, you may need to fit a relay to switch power for the solenoid. There are many diagrams available on google.

The behaviour you are seeing, on the dash panel (fuel gauge goes to zero), may be due to the way that the ignition switch is wired/constructed. Quite often, when you move the ignition switch to the start position, it will only switch power to a limited subset of circuits.

[jimd333]

The engine has been wired this way for many years. One day I ran the engine from the mooring to the dock. A little later, I went to start the engine and the problem began.
I believe that there is a short or open between the start panel and the engine.

[model 10]

Originally Posted by jimd333

Power lug to spade connector which is connected to 16g red/yellow.

So you have eliminated the new solenoid! Now run a jumper from the new switch to the new solenoid. Etc. etc. Caveman trouble shooting.

[Stu Jackson]

Originally Posted by jimd333

>>>>>>>>>>>>>>>>>>>>>>>>>>>
I believe that there is a short or open between the start panel and the engine.

Some boats have fuses between the start "button" and the solenoid. Old fuses and fuseholders present a potential for a broken path. Go check. Good luck.

Of course, this is a less expensive approach than replacing big parts.

[jimd333]

Originally Posted by Stu Jackson

Some boats have fuses between the start "button" and the solenoid. Old fuses and fuseholders present a potential for a broken path. Go check. Good luck.

Of course, this is a less expensive approach than replacing big parts.

Thank you, Stu. I've already checked that , but will further check with the multi meter.
I forgot to mention that the glow plug switch also makes the fuel guage peg to empty and no juice gets to the glow plugs.

[Elie]

Is it possible that you are dealing with a key-switch issue?. Any power between the ground and the start pole of the switch?, any power between the 2 small wires to the solenoid when the key is on start?. What about the 12 volt input to the key-switch?. Do you have by chance a relay that feed the instrument pannel(some diesel engines have that like the Perkins Prima).

[jimd333]

I bought a new switch. I don't see a relay, either in the boat or on the schematic. My multi meter shows power to the switch at the two contacts that should have power.
I'm debating whether or not to purchase a power probe to find the ground fault (short) or to spend the money on wiring a separate push button start switch and circuit for the glow plugs.

[MarkSF]

What you have is a high resistance connection, in the positive wire that supplies the panel. The clue is the fuel gauge playing up, which is probably fed by the same supply (I'm guessing, as apparently the exact model of engine is a secret).

I suspect that the engine is a Universal, and that you have the infamous and common problem with the trailer connectors that are inline between panel and the engine.

I spent a while troubleshooting similar but very occasional issues. The cure was a full trailer connector-ectomy.

Is it wired so you have to have glow plugs energized for the starter button to work? Another bad idea.

My suggestion is to stop throwing parts at it, and do some proper diagnosis.

[jimd333]

Originally Posted by MarkSF

What you have is a high resistance connection, in the positive wire that supplies the panel. The clue is the fuel gauge playing up, which is probably fed by the same supply (I'm guessing, as apparently the exact model of engine is a secret).

I suspect that the engine is a Universal, and that you have the infamous and common problem with the trailer connectors that are inline between panel and the engine.

I spent a while troubleshooting similar but very occasional issues. The cure was a full trailer connector-ectomy.

Is it wired so you have to have glow plugs energized for the starter button to work? Another bad idea.

My suggestion is to stop throwing parts at it, and do some proper diagnosis.

Not a mystery, but a test which you passed brilliantly, Mark
It's a Universal 5411 and I've been suspecting the "trailer " connections. Any tips on doing the surgery? Thanks so much!

[MarkSF]

The simplest approach is just to cut out the trailer connectors, and then rejoin the wires with heat shrink butt crimp connectors.

I found about six feet of excess wire, folded up, and taped over. This is because the Universal loom comes in one length that's far too long for most installations. So I removed that.

For the critical wires - the feed to the panel which takes a high current as the glow plug current passes through it, the glow plug supply wire, and the solenoid wire, I replaced with new ones, uprating to larger gauge.

I moved the low quality fuse holder in the solenoid wire to the panel, using a better quality waterproof blade type fuse holder.

If the alternator output still goes to the panel, through the ammeter, then back, this should be fixed urgently. Run a feed from alternator to starter +.

I replaced the ammeter with a voltmeter.

Theres a whole write up here :

http://www.pbase.com/mainecruising/u...upgrade&page=1

[jimd333]

Thank you, Mark and all who've replied. What a great write up and the additional link will also help immensely! Have a fine Independence Day and I'll check in when the job is complete.

[jimd333]

Originally Posted by jimd333

Thank you, Mark and all who've replied. What a great write up and the additional link will also help immensely! Have a fine Independence Day and I'll check in when the job is complete.

Well, the job is done and the starter is getting more volts than it's ever seen. One of the trailer connections was badly corroded, but not melted. Thanks again for the help!