1997 GT40 Loss of Electrical Power

[jamiewilson3]

Just got a new to me 1997 SN w/ GT40, 270 hrs.

We went out on the lake for the first time for a few hours. Got back and when we were putting the boat on the trailer, the slope of the ramp was such that I didnt even rub a bunk and hit the front of the trailer pretty good. I bounced off and bumped the throttle again and got the boat on the trailer, then turned off engine. Went to restart the engine, and there was no electrical power.

We pulled the boat out and went back to the house. Still no power, but after backing it into the garage, the power came back on.....stereo, lights, PP,etc. I turned the key to see if it would crank. The fuel pump ran and then heard a click, but that was it. Completely lost power again.

After this, when you turn the key, you can see the volt meter flick for a split second and then flatline. PP screen blinks on for a split second and that is it.

About 30 minutes later, the power comes back on again. Same thing.....turn the key, hear fuel pump, try to crank, click, and then complete loss of power.

Any suggestions?

[teamseal]

Fuse holder on the red wire in the battery box, Check it out.

[DanielC]

Clean the battery terminals, and the cable ends where they connect to the battery terminals.

[jamiewilson3]

Fuse holder on the red wire in the battery box, Check it out.

Thanks for the response. Pulled the fuse to check it. 50A time delay fuse. Used my multimeter to check continuity and it is still good.

[jamiewilson3]

Clean the battery terminals, and the cable ends where they connect to the battery terminals.

Terminals look to be in good shape. Would this account for a trip somewhere from a relay or safety switch? Dont mind doing it, but I will need to get some steel wool or something to clean them.

[jamiewilson3]

Perhaps eating a little crow.

I went out to clean the terminals with a wire brush that I remembered that I had. Honestly, the terminals were clean, so I didnt anticipate it fixing anything, but I figured 5 minutes of time to eliminate the cause 100% is time well spent.......

The terminals were fine, but as I go to pull the negative, it basically just slid off of the battery terminal. My eyes kind of lit up, that this may be it. I went ahead and cleaned both terminals and clamps, reinstall and tighten everything. Turn on the ignition and all is well.

I believe what happened is that the negative terminal was loose and the battery was all the way in the rear of the battery box. When I hit the trailer, it caused the battery to slide to the very front of the box, causing the negative terminal to pull loose enough to cause poor contact.

Thanks to both of you for your help!

[DanielC]

Battery terminals are made of lead. Lead naturally oxidizes by itself, if just left alone. Add to that the fact that the battery has sulfuric acid in it, and it is in a boat, an environment that is almost always humid, and it is a wonder that you do not have to clean the battery terminals every time you use a boat.

The number one cause of a no crank condition on an engine is the battery terminal connection.

[sls]

Just curious, do the cables look dirty when they are oxidized and need cleaned?

[DanielC]

The cables can look perfectly good, and not really be making good contact, and it is also possible for the outside of the cable clamp to look dirty, or even have corrosion on it, but the two surfaces that make the electrical contact to be good.

You need a good electrical connection. That is made between the outer diameter of the battery terminal (post) and the inner surface of the cable terminal (clamp).
When the two parts are put together, you cannot see in between them.

As this connection deteriorates, it slowly builds an increased resistance, and that resistance reduces the ease that the current flows through it. When that happens, you lose battery voltage at the connection, and this may cause the terminal to get warm, or hot.

Another symptom of a bad cable connection is this.
You turn the key on, and everything electrical seems fine. When you try to crank the engine, the huge amount of current the starter draws causes the available voltage to drop below the amount needed to hold the starter solenoid closed, so it opens back up, and then the available voltage goes back up, the starter solenoid reengages, and the cycle starts over, causing a rattling sound, and no crank. This will also happen with an almost dead battery.

[maxpower220]

Auto parts stores have a corrosion block spray for battery terminals. I use it on all of my batteries (car, boat, motorcycle, etc.). Clean the terminal, tighten correctly, and then apply the spray. At the end of the season, I disconnect the battery, spray, and leave on a tender during the winter months. In spring, clean, connect, and spray. I have had no battery problems since I have done this. A can of spray will last many years, even if you have many different devices to care for.

[teamseal]

Well I just had a flash back memory experiance ! Some times my brain does that! Some time along the 96,97,98 era we were getting power cables that had improper or lack their of crimp and soldering. If you have an original battery cable in your boat pull on the cable where it goes into the battery terminal connector it may come apart. A lot of times you can check it with a volt meter and it will read 12 plus volts but unless you check it with a load tester at the other end you may find that the connection in side the terminal connector has degraded.

[jamiewilson3]

Well I just had a flash back memory experiance ! Some times my brain does that! Some time along the 96,97,98 era we were getting power cables that had improper or lack their of crimp and soldering. If you have an original battery cable in your boat pull on the cable where it goes into the battery terminal connector it may come apart. A lot of times you can check it with a volt meter and it will read 12 plus volts but unless you check it with a load tester at the other end you may find that the connection in side the terminal connector has degraded.

Thanks; I will give them a good tug. Better to find out in the garage than out on the lake.