Engine starts by itself - Volvo Penta 2030

[socaldmax]

Originally Posted by a64pilot

I lived in Germany for a few years, and you don't know the half of it, you would see them out in the yard with scissors getting ever blade of grass perfect.
Go to the local automotive repair shop and it was literally as clean as a surgical operating room.
Can you think of anything German made that has a reputation for being junk?

All of the VWs I owned. 1978 Scirocco, 1977 Rabbit, a super beetle and a 1979 Scirocco.


Excellent engineering, but they sourced a lot of their parts from Brazil, I could see the voids in the cast metal parts - window crank handles, alternator bracket, intake port on the cylinder head, with my own eyes. Back in those days, they were built to a price point, not to the engineer's satisfaction.

Of course if you let a German engineer loose with an unlimited budget, you're going to get a product that will last forever and you'll end up never selling replacement units. LOL

[TheNomadTrip]

Update: I found the wiring harness connections throughout the boat. I tested all of the 16-pins on each connection and all were fine.

Then I think I found the culprit, almost by accident.

On the bottom of those damn relay boxes there's a hidden 16-pin connection. I didn't see it when I was fooling around in there earlier. I only found it when I was looking to test that last piece of the wiring.

Anyways - it's badly corroded, broken, and has clearly been sparking (arching?). Attached are a couple of pictures. Note the broken connection on the male end and the melted areas between pins on the female end.

The connection itself is non-essential so the mechanic is picking up some heavy-duty connecters in town today and we'll cut the 16-pin connection out, and connect the wires individually. Then we'll test, shrinkwrap, and waterproof the entire deal.

I really hope this is it.

[TheNomadTrip]

Originally Posted by socaldmax

All of the VWs I owned. 1978 Scirocco, 1977 Rabbit, a super beetle and a 1979 Scirocco.


Excellent engineering, but they sourced a lot of their parts from Brazil, I could see the voids in the cast metal parts - window crank handles, alternator bracket, intake port on the cylinder head, with my own eyes. Back in those days, they were built to a price point, not to the engineer's satisfaction.

Of course if you let a German engineer loose with an unlimited budget, you're going to get a product that will last forever and you'll end up never selling replacement units. LOL

Well, I'll take this German over the Italian "mechanics" that I've been dealing with previously. He's actually trying to save me money. The Italian guys? Trying to transfer my money into their pockets.

I realize an individual isn't representative of an entire country/culture. But in this case, the German wins.

PS - the German is indeed very logical and has systematically helped me go from what seemed like a large problem - to a very isolated one. The other guys, not so much.

[DeepFrz]

Great. Well done and I think you have probably learned a lot from this.

[Ex-Calif]

That's fugly. Congrrats in finding it.

Might want to check the other engine as well...

[a64pilot]

My first clue you had found the problem was seeing "Mexico" on the cannon plug

[Therapy]

Your fingers are too clean!

Go find another project.

No, really, I followed this thread (my favorite type) and am glad you narrowed it down.

It also goes to re-prove the axiom "It is always a connection".

Fair winds.

[Ex-Calif]

So did you find the ground relay and pass the German's test - LOL

[jimbunyard]

Even if that's not the source of the original problem (but I hope that it is), it's still a problem and needs to be fixed.

Eliminating the connector is probably the best idea, the means of eliminating it is the question. From the pictures, it looks like there is a medium to medium high corrosion risk in that location. So I question the wisdom of "shrink wrapping" the entire shebang after you've made all the connections. It's almost impossible to seal all those wires in a bundle, and wrapping them together can actually create a wicking situation that pulls water into the bundle, where it has trouble getting out (and you know what happens then).

Might get some disagreement here but if you're going to eliminate the connector, making it hardwired so that you can't disconnect it at the engine, the best way to do it is soldering the wires together and covering the solder joint of each individual wire with at least one layer of adhesive lined heat shrink tubing (I often use two and have sometimes used three).

If you're using butt connectors, at the very least make sure that you coat the wire and the inside of the connector with an anti-oxidation compound, it's called Oxgard or Noalox around here. I'd tend toward uninsulated butt connectors covered with, again, adhesive lined heat shrink tubing. And crimp the connectors with the right tool. And again no final complete wrapping, maybe a couple of nylon cable ties to neaten it up a bit.

In the interest of making the connections as permanent as possible.

On my boat I used male and female spade lugs, soldered and heatshrinked (heatshrunk?), to preserve the disconnect function and also to aid in future trouble shooting. And of course they are liberally coated with oxgard before being connected.

[Therapy]

Originally Posted by jimbunyard

Even if that's not the source of the original problem (but I hope that it is), it's still a problem and needs to be fixed.

Eliminating the connector is probably the best idea, the means of eliminating it is the question. From the pictures, it looks like there is a medium to medium high corrosion risk in that location. So I question the wisdom of "shrink wrapping" the entire shebang after you've made all the connections. It's almost impossible to seal all those wires in a bundle, and wrapping them together can actually create a wicking situation that pulls water into the bundle, where it has trouble getting out (and you know what happens then).

Might get some disagreement here but if you're going to eliminate the connector, making it hardwired so that you can't disconnect it at the engine, the best way to do it is soldering the wires together and covering the solder joint of each individual wire with at least one layer of adhesive lined heat shrink tubing (I often use two and have sometimes used three).

If you're using butt connectors, at the very least make sure that you coat the wire and the inside of the connector with an anti-oxidation compound, it's called Oxgard or Noalox around here. I'd tend toward uninsulated butt connectors covered with, again, adhesive lined heat shrink tubing. And crimp the connectors with the right tool. And again no final complete wrapping, maybe a couple of nylon cable ties to neaten it up a bit.

In the interest of making the connections as permanent as possible.

On my boat I used male and female spade lugs, soldered and heatshrinked (heatshrunk?), to preserve the disconnect function and also to aid in future trouble shooting. And of course they are liberally coated with oxgard before being connected.

+1

[socaldmax]

I've used heat shrink soldered butt connectors in the past, they worked great, made by Raychem, possibly other brands.

[skipmac]

Originally Posted by jimbunyard

Even if that's not the source of the original problem (but I hope that it is), it's still a problem and needs to be fixed.

Eliminating the connector is probably the best idea, the means of eliminating it is the question. From the pictures, it looks like there is a medium to medium high corrosion risk in that location. So I question the wisdom of "shrink wrapping" the entire shebang after you've made all the connections. It's almost impossible to seal all those wires in a bundle, and wrapping them together can actually create a wicking situation that pulls water into the bundle, where it has trouble getting out (and you know what happens then).

Might get some disagreement here but if you're going to eliminate the connector, making it hardwired so that you can't disconnect it at the engine, the best way to do it is soldering the wires together and covering the solder joint of each individual wire with at least one layer of adhesive lined heat shrink tubing (I often use two and have sometimes used three).

If you're using butt connectors, at the very least make sure that you coat the wire and the inside of the connector with an anti-oxidation compound, it's called Oxgard or Noalox around here. I'd tend toward uninsulated butt connectors covered with, again, adhesive lined heat shrink tubing. And crimp the connectors with the right tool. And again no final complete wrapping, maybe a couple of nylon cable ties to neaten it up a bit.

In the interest of making the connections as permanent as possible.

On my boat I used male and female spade lugs, soldered and heatshrinked (heatshrunk?), to preserve the disconnect function and also to aid in future trouble shooting. And of course they are liberally coated with oxgard before being connected.

Agree with most of the above: wrapping and wicking and more. You will certainly get other opinions on the soldering. The other opinion is soldering creates a hard spot that in any wire subject to vibration or movement can weaken and break. Had friend in the navy years ago who told me SOP was crimp connectors only, no solder. Good modern crimp connectors come with outer shrink tubing and internal sealer so when you heat it not only does the outside shrink down to seal, the inner is coated with some kind of goop.

[Cheechako]

Originally Posted by DeepFrz

Yes, and the Germans did/do have a wonderful apprenticeship program. Exceptional training.

Yep. My lead machinist/millwright in my machine shop was German. Came over here after the war. Talk about knowledge.. wow. he had some great tricks for metal cutting and working.
He said when he was an apprentice, they gave him a file and some rectangular pieces of steel. He filed on those for many days before they even let him go to something else. The filing had to be perfect and there was only one way to do it!

[jimbunyard]

skipmac,

I've heard that too, and it makes sense. I've never seen it in any of the boats or vehicles that I've wired, but that doesn't mean it doesn't happen. I've also heard that the flux used is hydrophilic and can induce corrosion, which also makes sense though I've never seen that either. Of course the oldest connections that I have in use here for comparison are only 19 years old, so the jury is still out.

I guess I could be called a soldering advocate mainly for two reasons. The proper tool to make correctly crimped connectors is often not available and people wind up using pliers or those cheap (and sometimes not so cheap) multipurpose crimping tools from
Walmart or wherever. An improperly crimped connection is an invitation to headaches, if not worse.

The second reason is more personal; I have three different sized little rolls of adhesive heat shrink, one of those 'not so cheap' cheap stripper/crimpers, a soldering kit, an assortment of terminals and an inexpensive digital volt/ohmmeter in my 'electrical tool kit' on board, and can be sure of making almost any trustworthy electrical repair or installation with a minimum of 'hardware runs'.

A crimped/soldered/heat shrunk connection has another advantage over a crimped/heat shrunk one. Properly done, solder seals the end of the wire, so if adhesive heat shrink is used over the crimp portion of the terminal and, say, maybe five or six times the diameter of the wire down the length of the wire from the terminal, water in any form is very effectively prevented from wicking. This very morning I finally found an intermittent power supply problem with one of my Garmin instruments; the factory crimped connector on the instrument side of the power supply fuse holder had corroded. There was no corrosion on the part that held the fuse or the fuse itself (oxgarded), and the wire is inside a completely dry cabin. The water causing corrosion was either condensation, or more likely in what seems to me the humidity capital of the world, water vapor, and had worked its way about 4 inches up the power wire.

Also, wouldn't a wire crimped securely enough to ensure that it wouldn't pull out also make a 'hard spot' at the crimp? Just saying.

[DeepFrz]

Skip, you aren't ever going to convince someone that believes in soldering a connection that it isn't a good idea on a boat. We have many threads that show me that. However I am glad you mentioned it because someone else may read it and take your advice and in that way save themselves a lot of trouble.