05 24V 6.0L MP - Need Alternator???

[kjohnson709]

Hi guys,

I think I am going to try to replace my alternator. It seems it is starting to have issues as the volts drop below 11 on occasion even when the boat is under power. I have also noticed that even right after we get off the water the batteries are not fully charged.

Another issue that we have on occasion is that when we hit a very large wave or chop that jars the boat there seems to be some sort of short in the electrical system. All the gauges turn off, the helm beeps, perfect pass turns off, radio turns off and even sometimes the engine shuts off. Everything seems to kick right back on within a second or two. I know it is not the batteries becasue I just put two brand new batteries in and all connections to the batteries are tight. The shut off issue happened before I replaced the batteries.

1) Do you guys think this could be the alternator not charging the batteries properly or shorting out? If so, would you know what alternator I need? I imagine it is GM/Delco since the motor is the GM Vortec 6.0L but the model number sticker on the one I have is missing so I have no part number.

2) Could it be a short somewhere in the B+ line that runs from the engine to the amp to the helm? Is so, any ideas on where I might try to isolate where the short is?

Thank you,
Kyle

[chpthril]

it is starting to have issues as the volts drop below 11 on occasion

Need to treat the gauge display as a symptom and not as an absolute. Cannot rely on it for anything other than the voltage lever at he gauge and not an indication of the system voltage. You need to use a digital volt meter to diagnose the alternator and any electrical issues.

All the gauges turn off, the helm beeps, perfect pass turns off, radio turns off and even sometimes the engine shuts off.

This would not an alternator charging issue. Sounds like the bad connection or failed terminal end. This could also be the cause of the low voltage reading on the helm.

[Wakeman22]

As said above. I would look at the connections anyplace along the wire path from the batty to fuses to helm and key switch. Could be a ground issue as well.

[kjohnson709]

Thanks guys. I was curious how accurate the actual gauge might be.

I will climb under the helm and look for loose connections. It is an absolute rats nest under there though. I recall where the B+ cable comes in up under the helm becasue thats where my B+ ballast switches are tapped in. I guess I will start there.

My stereo amp is mounted on the inside wall of the midship locker on the port side. One time the amp actually fell off from its mount and I had to drill new holes into the glassed in wood and re-mount it. Could a loose connection on the amp cause the symptoms I am having (e.g. all gauges and engine shutting off) or would that only impact the radio?

[kjohnson709]

actually I am glad you mention the key switch Wakeman22. This last outing I turned the key and nothing. No beep, no starter action - just nothing. Then i waited 30 seconds, and tried it again and the boat started as normal. perhaps when we hit a big wave it makes a connection loose contact.....but where it might be. I will try to do some detective work and find it.

[gumby]

Another thing to check is the terminal on the back of the alternator. With all of the power we use with the boat off (radio, amps, lights, ballast,) We ask a lot of the wires and sometimes they get crispy..Just fixed a friends on his 2004 tige his was beyond crispy.well done.but like the others said i don't think it is causing all of your problems but is something to watch out for.

[chpthril]

Helm volt gauge can be accurate to indicate an issue, but once there is an issue, its best to use a hand held volt meter as your diagnostic tool.

A poor connection at an amp, would likely only impact the stereo. May even only impact the actual speakers powered by said amp.

[kjohnson709]

Thanks Chpthrill. I had visions of messing something up when I re-mounted the amp.

sounds like it is either a ground or B+ issue under the helm, somewhere before each individual component perhaps since all are impacted when it shorts out.

[kjohnson709]

Once again I think you guys saved me time and money!

I started at the ignition switch and found that this connector was very loose (the screw was nearly falling out). With the hose hooked up and the engine, gauges, and radio on I was able to duplicate the problem I had out on the lake when I jigged these wires. There was a small spark and then everything would die and then come back on.

I tightened this up and I am getting 12.6V at the alternator and the volt gauge immediately jumped to 13v.

my gut is that this solved my problem! Thanks guys!

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[h2osk8er00]

Always good to remedy things on your own with the help of fellow TO's. Congrats man! This site should be voted top boating forum!

[gman]

Do you have 4 ring tounge connectors under one screw/terminal?

[kjohnson709]

I believe so. This is how I bought the boat. The ignition has a few different posts and all are full up with connections. Is this bad?

[chpthril]

It can lead to issues. Too many loads can lead to excessive draw through the switch. Those screws are typically short. Every ring means less threads through the switch terminal, making a loose bolt easier. This leads to voltage drop, arching or stuff just not working at all. might be worth looking into dissecting the leads to see what they are and moving some to a BUSS strip or possibly through a relay.