Electric Mayhem!

[jfkkesler]

SO I recently completed a complete gas tank swap. Everything was going great, until I went to start my boat up, and...... nothing. During the gas tank installation the only piece of electronic gear I changed was the sending unit. To rule that out, i disconnected it and tried again, nothing. When I hook my battery up, the dash reads about 13 volts, and then when I turn the key, the starter clicks, and I lose all battery power. The dash shows 0 and the key no longer works. I have to go back, disconnect, then re-connect the battery, and it does the same thing. What could possibly have gone wrong? I did an inspection, and all the cables look fine. I'm not really good with this stuff, and I would appreciate some help! Thanks guys.

 

[phwrd]

Re: Electric Mayhem!

My first inclination is that it is a ground wire problem. Did you rewire it all the way to the dash? Is is grounded ? Is it Fused ?

Double check the instructions to make sure you didn't wire backwards.

 

[jfkkesler]

Re: Electric Mayhem!

I checked all the grounds. At the battery, on the positive end of the cable is the clamp for the terminal, and there is also a black wire that runs back from the end of the cable about 4 inches. It isn't connected to anything. What is it for? Is it a ground? I'll go inspect all the grounds one more time though. I also checked the fuse panel. Everything looks good, and I pulled and reset all the fuses just in case.

 

[jfkkesler]

Re: Electric Mayhem!

Also, When I wired the sender, I just added some new wire to the end of the old wire, so i didnt have to rewire it all the way up to the dash. The sender was working perfectly until I disconnected it. It is still having issues with the sender disconnected.

 

[escapade]

Re: Electric Mayhem!

Do a load test on your battery sounds like its failing under load.

 

[Silvertip]

Re: Electric Mayhem!

It is not uncommon for gauges to go to zero while cranking the engine since power from the "A" terminal on the switch is removed until the key comes back to the RUN position. Put a voltmeter on the battery and then turn the key to START. If the meter drops below 11 or so, you have an extremely high current draw, bad battery cables or connections, or a bad battery. You need to check both ends of each battery cable. Pay particular attention to the area where the insulation meets the terminal at the ends of the cables. Any bumps or bulging in that area indicates corrosion is at work. Repair the cable with new ends or replace the cable. Have the battery load tested to ensure it is up to snuff.

 

[tic]

Re: Electric Mayhem!

Silvertip is right: as far as guages go, AC lies and DC dies.. a 12v DC guage will go to zero if there's a short or not enough power... Alternating current guages are different but we don't have those in boats.. I'd be looking at connectors and grounds.. Sucks to chase renegade electrons I know, sneaky bastids.

 

[jfkkesler]

Re: Electric Mayhem!

Well I did get it working. I put the battery on the charger for about 15 minutes, found and tightened every ground I could, and what do you know, fires on one crank. I'm going to try again in the morning to see if it works then too. What does the process of replacing the cables look like? It looks like they go into the motor and back out again. They have a habit of heating up and melting the rubber sleeve around them at the terminal end. What would cause that? I have made sure the connections are nice and tight. Thanks for all the great help, also, details on the process of load testing a battery? And I know you will all probably scold me for this, but I have been using a marine deep cycle battery as my starting battery. bad idea? What is the difference between that and a starting battery?

 

[jerry1865]

Re: Electric Mayhem!

if you are running an outboard , a deep cycle batt. is a poor choice for a starting battery. it can (and usually does) cause the charging system to go out. power packs and timer bases cost more than a batt.
the voice of experience ..lol
but it does explain some of your heat issues, the new charging system can put out 35 amp, but only on high demand. the thing is that they overheat easily when hooked to a marine battery.

 

[Silvertip]

Re: Electric Mayhem!

Load testing a battery is done at an auto store or service facility. They place a large load on the battery using a carbon pile which forces the battery to deliver it's maximum amount of current. If the battery can deliver the amps indicated on the label, it is ok. If not, it is likely headed for battery heaven. As for a charging system not working properly with a deep cycle battery, that is absolute nonsense. The only issue with charging systems and batteries is on non-regulated charging systems (which there are few of these days) was that maintenance free batteries seem to have issues with overvoltage. As for using a deep cycle as a starting battery, that too is not an issue although a marine starting or "dual purpose" (deep cycle/starting) is a better choice.

Your cables are heating up because you still have a loose/corroded cable issue somewhere. Looking at connections is not a solution. You need to disconnect, clean (as in make connections shiny clean) and retighten all positive and negative battery cable connections (both ends) and inspect all cables for corrosion around the terminals.

The dangling black wire off the negative battery cable is probably not used as it appears to be an automotive cable. The negative battery cable connects to the engine block so that extra wire is not needed although it could be used for the ground connection for "boat harness" which is the smaller pair of wires that feeds the fuse panel.