Calling all total loss gurus, electricians, and electrical engineers

[McDog]

I recently rewired a total loss and after using it and it functioning perfectly I discovered that it was throwing current into my carbon hull where the ebox attaches to the hull and melted my epoxy out of the carbon around one bolt hole. I haven't torn into it yet but I'd like to trouble shoot it some as far as possibilities before I do while I am bored at work today.

I run all my grounds to a common post in the anodized aluminum ebox. I run an extra ground wire to the engine case and straight to the negative battery post from the ebox in addition to the one on the pickup plate and the main ground wire from the starter mount. I have ran all my total loss ignitions this way trouble free for years, and this exact setup has been well used prior to going in this hull.

I am not an electrician or a physicist so I'm asking for help eliminating possible problems that I can address.

1. I somehow miswired something. (I'm sure it's the most likely because I'm human but I am also pretty ocd and I've wired so many systems now that I've lost count.)

2. A power wire is damaged and touching the ebox.

3. The brain is somehow malfunctioning and sending current when it shouldn't?

4. The solenoid is malfunctioning and sending just enough current to drain battery and heat ground wires but not enough to turn starter?

Any other ideas? Are my ideas feasible? It doesn't make sense to me that current can run into the ebox which is grounded and out a mounting bolt to the hull if it is working correctly, but I swear the ski ran fine other than the battery drain and the smoking hull.

 

[Storbeck]

I'm not completely understanding how you have the grounds set up, but do you have multiple paths to ground? Possible explanation is a ground loop, very weird things can happen.

For example if you had ebox directly to battery, and ebox also to motor, then motor to battery. During cranking there can be a voltage drop on the motor to battery ground cable, so the motor is at some voltage higher than the battery ground, and you have weird things happening in the loop going from there to ebox and back to battery.

 

[Christian_83]

im not sure i fully understand your problem. You are melting the epoxy? could you post some pictures to show the problem?
The anodising is able to create a insulating layer, so maybe you show equal out the potentials from the inside exbox ground post, to a post in the carbon hull yourself.
Its not aluminum that is tearing up, due to galvanic corrosion (carbonfiber, saltwater and alu)?

 

[McDog]

Come to think of it, I usually dont do the extra battery connection. Maybe that's the culprit. But I will say that the smoking carbon happened while the ski was not running.

 

[McDog]

Current ran through the ebox mount bolt into the carbon hull and burned the carbon around the bolt hole to the point that the epoxy was gone and it was dry cloth.

The common ground post in the ebox has no anodizing on the connection surface, and the mounting bolts are going into threads that aren't annodized.

 

[Focusrally]

With a multi meter put one lead on the negative battery post and with the other check for voltage at various places you would expect to be grounded. If you find voltage anywhere then you have a grounding issue. It would be best to do this with the engine running

 

[McDog]

Thank you and I'll try it, but to me it seems highly unlikely to have a grounding issue with 3 grounds (pickup plate, battery, engine case) all taken to a common post. It seems like it should be something else. What are the odds that all three of those went bad at once? Maybe I'm misunderstanding what you are saying?

The idea that somehow the battery terminal ground being in the mix is affecting it seems plausible but I will be honest and say I don't understand how.

 

[Focusrally]

My thought process is that it will take the path of least resistance. If that ends up being through the hull then I would expect to find a wiring problem

 

[mikesx]

+ is getting to -. I'd suggest one at a time removing a ground from your ground stack, reinstalling the others as they were, and putting your volt meter in series with the removed ground ( black of meter to post/stack, red of meter to removed ground). Repeat whole process with each ground to find path that + is coming thru. What box are running? Am or Stock? Are you running a box or plate?

 

[mikesx]

If you have a high quality vom,(like a Fluke) lift your + battery terminal and see if there is continuity between the lifted + cable and the hull. Then check other + (red) devices ,start/stop, starter,posts on start relay etc. for any cont. to the hull. Carbon hulls can be a nightmare for ground paths because it is impossible to " completely " isolate them (cooling lines>h2o>motor).

 

[McDog]

I'm running a box. It's a cold fusion ebox with an old ATP flame ignition. Come to think of it, the ebox back is OEM and the anodized part is just the front on this setup.

 

[Harbor]

ill add, try to do your visual inspection and voltage drop measurements before taking stuff apart or the grounds stack apart if possible. Touching/disturbing it first may correct it before you have the chance to know you found it.

 

[mikesx]

ill add, try to do your visual inspection and voltage drop measurements before taking stuff apart or the grounds stack apart if possible. Touching/disturbing it first may correct it before you have the chance to know you found it.

Exactly , that's why I suggest one @ time while reinstalling others. The fun of electricity.

 

[mikesx]

I'm running a box. It's a cold fusion ebox with an old ATP flame ignition. Come to think of it, the ebox back is OEM and the anodized part is just the front on this setup.

You got thru box starter wire posts?

 

[Harbor]

+ is getting to -. I'd suggest one at a time removing a ground from your ground stack, reinstalling the others as they were, and putting your volt meter in series with the removed ground ( black of meter to post/stack, red of meter to removed ground). Repeat whole process with each ground to find path that + is coming thru. What box are running? Am or Stock? Are you running a box or plate?

Exactly , that's why I suggest one @ time while reinstalling others. The fun of electricity.

It wasn't clear to me you ment measure first take apart second, so I mentioned it.

 

[mikesx]

It wasn't clear to me you ment measure first take apart second, so I mentioned it.

Yeah man electrical problems are best solved by "finding" the problem . I hate the ones that magically fix themselves like blown fuses that work just by replacing the fuse.

 

[McDog]

The connections are inside the ebox. It's a stock ebox back with an aftermarket top that allows you to open it with an oring sealed clear lexan plate.

 

[McDog]

 

[mikesx]

You have a meter? Post pic of it.

 

[hornedogg79]

What is the connection on the battery side of your relay? Since it's melting your hull and not blowing a fuse I'd be looking for bypassed wires like that.