Noob did something dumb - electrical

[pmsold]

bought a second hand 1999 Rinker 180 with 3.0 Merc cruiser and alpha one drive. I have a single battery setup. When I bought the boat, I removed the battery and stored it indoors for the winter. I have not used the boat. I went to hook the battery up last weekend and I inadvertently hooked both ends of the trim motor to the positive battery terminal for a few seconds. It smoked and I removed the cables. Everything in the boat worked before hand (radio, horn, starter engaged) After my screw up, the boat was completely DEAD, and I searched and found an inline fuse at the red battery selector. The fuse is a 30A, 250V glass fuse and it was burned out. Thinking I got lucky, I bought another 30A fuse but only a 32V at autoparts store. When I replaced the fuse, something electrical (bilge?) worked for about 3 second, and then the fuse burned out. Could the fact that I used a 32V fuse be an issue? Why in the world would a 250V fuse be used in a 12V battery system? I am having a hard time finding a 250V fuse, but I will get one. Do you think I could have fried the trim motor? Is there another set of fuses beside the dash and the one on the top of the motor?

Thanks for any insight on my knucklehead move.

 

[StarTed]

The voltage rating of the fuse is not a problem as long as the rating is greater than your power source. That's 12 volts in your case. The 32 volt rated fuse is fine. You have another problem.

Try disconnecting everything and then reconnect them one at a time until you find the problem.

Both ends of the motor wiring shouldn't have shorted out anything unless one of the wires goes to the other battery terminal. It's probably physically grounded to the engine which is connected to the battery - terminal (ground). Make sure you get the polarity correct for the wiring.

Here's a hint: connect a heavy load such as a spotlight between the wire you intend to connect and the terminal before connecting. If the light comes on bright look for a problem.

Hopefully you didn't fry something in the trim unit or your wiring.

 

[64osby]

Test with a multi meter prior to installing new fuses. unless you buy a lot of them.

 

[gm280]

:welcome : pmsold to iboats...

Sorry to hear about your electrical situation. But I really have a hard time understand what you did. You stated that you hooked both positive and negative wires from the trim unit to the positive battery terminal. If that is exactly what you did, I can't see how anything happened. There was no complete circuit that I can see. Unless the trim wires were both trim up and trim down and not positive and negative wires. Then I can see a problem. And even if you did connect trim up and down wires, nothing else in the boat should have been effected.

Like StarTed suggested above, remove all wires from the positive terminals and start connecting one at a time until you find the problem. Post your results. JMHO!

 

[pmsold]

Ok, so what I did to start was take the main battery cables and connect them. Accessories and motor turned over. TRIM did not function.
The seller had told me that all wires connected to positive terminal outside of main negative terminal. The the two trim connection- one was a single wire and the other had three wires going into the battery connector. I had hooked them both up to the positive and that is what created the spark/ smoke. The seller then told me that the three wire connector should have been on negative. Then after I removed the cables the boat was dead. I then found the inline fuse at the battery switch that was melted. When I put in new fuse and hooked up just the main cables the fuse smoked again.

 

[Grub54891]

These type of thing's happen quite often. You melted a wire someplace in the harness, start by opening up the harness at the nearest source by the battery. Once you find the short, repair it correctly with marine grade wire, shrink tube connectors, and wrap it back up nicely.
Now go back to the battery, unhook all extra wires, all that should be there is the main wire to the starter and the main ground. Add a nice bus bar, back there to hook up all other accessories to correctly.
Now whenever you need to pull the battery, you only have 2 wires to worry about .ABYC standards do not allow more than 4 wires at any connection, and you more than likely don't, but it will be a much nicer layout and less likely to cause any issues. Problem solved.

 

[redneck joe]

Welcome to the club, and personally i buy a lot of fuses. Typically you wont burn out the whole system just fuses. Thats why they are there. Keep digging.

 

[tpenfield]

I am just trying to visualize how you hooked up both ends of the trim motor to the + battery terminal :noidea:

Perhaps there is some wiring that has been disconnected or 'customized' by the previous owner that will compound the issue?

 

[pmsold]

Yea, the wiring is not the prettiest, as there have been "modifications". I have a feeling I will be spending a good amount of time under the cover with the continuity tester looking for the short. That is the only thing that makes sense. At this point, I have only verified that the battery switch works. I will start with the other side of the wire were the 30A fuse blew to try and find the short.

 

[desertrat301]

I think you have another problem entirely besides the trim motor. Hooking both positive and negative terminals to the positive terminal would not do anything. There is no energy flow from positive to positive. I would suggest taking an good look at the main wires running to the batteries and try and decide which ones are negative and which are positive. The majority of 12v applications ground back to the engine with a ground cable from the engine to battery.
My guess is that you have connected a direct ground wire (i.e engine ground) directly to the positive terminal.

 

[tpenfield]

pmsold -

Can you post a few pictures of the wiring and indicate where you connected the battery ? I think that may help with further responses.

 

[pmsold]

No Title

ok - an update. I traced my ground for the trim motor back and realized that I did have it hooked up incorrectly - hooked the trim ground to the ground on the battery, and I also discovered that the trim motor is direct wired to the battery control switch - I wouldn't have expected that, and it does not appear to be backyard engineered. Trim motor works fine now that I have the ground connected correctly.
As I went looking for my short, I discovered some wiring had melted behind the dash gauges and two were together. I separated them, and now the 30amp main fuse at the battery switch does not blow and everything appears to work. I did not start the boat as I do not have water available. The original culprit wires(3 black) that I hooked to the positive are unhooked (picture attached), and I do not know what they could be for - maybe grounds for the dash gauges? I did not look over the lights to see if they work either.
My main concerns are around repairing the wiring behind the dash, and need to verify if I have spark at the cap, and if the alternator charges.

 

[gm280]

ok - an update. I traced my ground for the trim motor back and realized that I did have it hooked up incorrectly - hooked the trim ground to the ground on the battery, and I also discovered that the trim motor is direct wired to the battery control switch - I wouldn't have expected that, and it does not appear to be backyard engineered. Trim motor works fine now that I have the ground connected correctly.
As I went looking for my short, I discovered some wiring had melted behind the dash gauges and two were together. I separated them, and now the 30amp main fuse at the battery switch does not blow and everything appears to work. I did not start the boat as I do not have water available. The original culprit wires(3 black) that I hooked to the positive are unhooked (picture attached), and I do not know what they could be for - maybe grounds for the dash gauges? I did not look over the lights to see if they work either.
My main concerns are around repairing the wiring behind the dash, and need to verify if I have spark at the cap, and if the alternator charges.

pmsold, from the picture you posted, it looks like the terminal is corroded and needs to be cleaned back to bright shiny metal before reattaching. And I would do that to all your electrical connections as well. And replace the burnt or melted wires. They are no longer quality wires and won't carry as much current as new. Glad to see you've isolated your problems with the short. :thumb:

 

[pmsold]

Thank you for the advice. I still have another couple weeks until I can get out on the water, so I have time to make up some new wires. It appears that all of the grounds melted a bit behind the dash. I truly appreciate all of the advice and encouragement. I am part of many forums, and the amount of responses and advice was much better than most.
Now I will look up how to add a second battery to the boat - I already have the switcher!

 

[desertrat301]

The three black wires that are hooked together are definitly your main ground wires. Being that a boat does not have a metal frame like a car all grounds must be wired directly to the battery.

 

[pmsold]

Well, I spoke to soon. I had some assistance and I checked for spark at the distributor cap- no dice! I am going to clean up the grounds and retry. Any other place to test for spark in the ignition line?

 

[pmsold]

Well , I spoke to soon. I had some help today and I tried to test for spark at the distributor- no dice. I am going to clean up the negative connections and try again. Is there anywhere else to check in the ignition circuit? There is power at the main 50amp fuse on top of the engine.

 

[Grub54891]

No spark, did you check/ clean the points?