Basic Electrical Repair - '85 Bayliner

I'm attempting to bring my (inherited) '85 Bayliner back to life. I went to the boat shop yesterday and purchased a new 500 amp battery. The dude behind the counter at the shop told me that the old 730 amp battery that came with the boat was way too big for my (inherited) 50 hp Force motor and it's 6 amp alternator. He also told me that the voltage regulator was most likely damaged due to excessive load from the old too-large battery.

So I have several questions:

1) Is the guy at the boat shop correct?
2) Attached is a photo of what the thoughtful PO left behind under the seat. I assume the thick cables are from the engine and attach to the outer posts. I assume the yellow and red wires with the ring are the ground and attach to the negative inner post. Is this correct?
3) Now it gets messy. The red wire with electrical tape ends in a broken fuse holder and a second red wire has been snipped in two. In the glove box I found 1/2 of a damaged fuse holder and a black wire with a second fuse holder. I assume both these wires (with fuses) are supposed to attach to the positive inner post. I assume I need to replace the fuses and holders, splice them into the existing red wires and seal with heat shrink tubing. Correct?
4) Or, instead of replacing the fuses and holders, would I be farther ahead to install a fuse box under the console? The boat is equipped with a fish finder and bilge pump and I may want the flexibility to add additional accessories in the future.
5) I assume the plastic box is for the battery. Is it supposed to be fastened down in any way or does the battery just rattle around free?
6) Finally, I've seen a couple of posts that mention the Universal voltage regulator. Would it be a good idea to replace my (potentially damaged) regular with the Universal? How would I test my regulator to see if it's properly working?

Thanks much! Sorry about the long post.

Re: Basic Electrical Repair - '85 Bayliner

Brian your post is likely going to be moved to the "electrical" forum by one of the moderators. So look for it there when it does.

1) no, the amount of "load" on the alternator is a function of what is used out of the battery and what the electrical system needs, not the amp rating of the battery. Think of a battery is if it were a water tank. The starter only takes a little water to turn. The alternator refills the water used by the starter. The amount of water used, and the amount returned is not determined by the size of the tank.

Re: Basic Electrical Repair - '85 Bayliner

As for your wire situation, trace all the cut wires back to whatever it was and find out if its a component you want in the boat, if not then take it out and remove the wiring, after you've done that possibly see if there is a wiring diagram somewhere for your boat? If not then your going to need to trace wires and get yourself a multimeter. Once you get your charging system and battery hooked up then start checking for power and ground at all your components, draw it all out and mark off what has power and ground as you go. I'm doing the same for the boat Im working on now.

Re: Basic Electrical Repair - '85 Bayliner

I redid a buddies boat and we pulled a 5 gallon bucket of wire out of it, 90% of it didn't go to anything so you may be in for a little trial and error.

The big cables go to the mtor and it would be safe to assume red is+ and the black is - as for the rest of the wires it is easier to start over as color doesn't mean anything alot of times.

I am guilty of this on my boat, I have several black wires that are actually posative, you tend to use what you have

Re: Basic Electrical Repair - '85 Bayliner

drewpster said:

Brian your post is likely going to be moved to the "electrical" forum by one of the moderators. So look for it there when it does.

1) no, the amount of "load" on the alternator is a function of what is used out of the battery and what the electrical system needs, not the amp rating of the battery. Think of a battery is if it were a water tank. The starter only takes a little water to turn. The alternator refills the water used by the starter. The amount of water used, and the amount returned is not determined by the size of the tank.

Click to expand...

Thats about the best description i've come across, go with the assumption that only 50% of all boat store employees have ANY clue about what there talking about.

Re: Basic Electrical Repair - '85 Bayliner

I may be missing something here but I think the guy at the shop is crazy. The regulator is designed to work in the direction of the alternator to the battery to prevent overcharging. Doesn't matter the amperage of the battery there both 12 volts. And the voltage regulator doesn't know what motor is on the other side of it. It works the same whether it was starting a 5hp or a 500hp. The only correct thing that guy might have said is that the 500 amp battery may be to big. That might true in terms of cost. The motor might start fine with 500 amp battery, and you could save some money over buying a 750 amp. I would also get a another deep cycle battery and use the starting battery for the motor only. Starting batteries are not designed to be continually discharged and recharged. A deep cycle will allow you to run radio, trolling motor, fish finder ect. without fear out ruining your starting battery or discharging it when you need it.

Re: Basic Electrical Repair - '85 Bayliner

Lion hunter said:

I may be missing something here but I think the guy at the shop is crazy. The regulator is designed to work in the direction of the alternator to the battery to prevent overcharging. Doesn't matter the amperage of the battery there both 12 volts. And the voltage regulator doesn't know what motor is on the other side of it. It works the same whether it was starting a 5hp or a 500hp. The only correct thing that guy might have said is that the 500 amp battery may be to big. That might true in terms of cost. The motor might start fine with 500 amp battery, and you could save some money over buying a 750 amp. I would also get a another deep cycle battery and use the starting battery for the motor only. Starting batteries are not designed to be continually discharged and recharged. A deep cycle will allow you to run radio, trolling motor, fish finder ect. without fear out ruining your starting battery or discharging it when you need it.

Click to expand...

Typical , that "knowledge" is never backed by experience..just assumption.

Re: Basic Electrical Repair - '85 Bayliner

Thanks everyone. I'm going to drop the battery in tomorrow, get out the voltmeter, and start tracing wires. As a future project, I will look at adding a second battery.

Does anyone have an opinion as to the best way to secure the battery to the boat? Or does the thing rattle around freely?

Re: Basic Electrical Repair - '85 Bayliner

Brian_in_Waterford said:

Thanks everyone. I'm going to drop the battery in tomorrow, get out the voltmeter, and start tracing wires. As a future project, I will look at adding a second battery.

Does anyone have an opinion as to the best way to secure the battery to the boat? Or does the thing rattle around freely?

Click to expand...

You don't want it rattling away. Look for a battery box that can be mounted or build one.

So you decided to continue with the project, assuming it's the same one you had posted earlier on.

Re: Basic Electrical Repair - '85 Bayliner

I'm very game to continue! Maybe my posts sounded more discouraged than I feel. The fact is, I haven't posted anything new on my first thread because I haven't had a chance to work on the boat in the past week (darn day job!)

I did get a chance to go to the boat store to get a new battery, and I've been reading and trolling thru the forum in an attempt to get myself up to speed with 12v boat wiring as it applies to my situation. I've seen mention of a couple good reference books, so I plan to hit the library or Amazon.com also.

In the meantime, I'm trying to decide how much electrical work to take on at the beginning of the project. Shall I repair what I have or gut everything and re-do?

Right now, I'm leaning toward repairing what I have so I can focus on replacing the deck and maybe (gulp!) the transom. Then, after I get the boat in the water, I can evaluate what modifications and enhancements I want (and can afford) to take on.

In the short term, it sounds like I need some sort of way to fasten down my new battery. If you look at the pic in my original post, I have a plastic battery-shaped box that came with the boat. There isn't an obvious way to attach it to the hull, so I am looking for advice.

Re: Basic Electrical Repair - '85 Bayliner

Brian,
I may be wrong but i believe that area is raised above the hull? If it is you should be able to just screw that plastic box down with 2 screws along with a couple washers. set the battery down in the box and you'll be golden.

Re: Basic Electrical Repair - '85 Bayliner

Brian_in_Waterford said:

1) Is the guy at the boat shop correct?

Click to expand...

Answered above, but I would say definitely not

Brian_in_Waterford said:

2) Attached is a photo of what the thoughtful PO left behind under the seat. I assume the thick cables are from the engine and attach to the outer posts. I assume the yellow and red wires with the ring are the ground and attach to the negative inner post. Is this correct?

Click to expand...

I would say no, I would "assume", (and we know the definition of assume right?), the red and yellow go to the positive side of the battery... but without knowing what the PO has done, you will have to trace the circuits and see... you definitely don't want to put them on the wrong post!

Brian_in_Waterford said:

3) Now it gets messy. The red wire with electrical tape ends in a broken fuse holder and a second red wire has been snipped in two. In the glove box I found 1/2 of a damaged fuse holder and a black wire with a second fuse holder. I assume both these wires (with fuses) are supposed to attach to the positive inner post. I assume I need to replace the fuses and holders, splice them into the existing red wires and seal with heat shrink tubing. Correct?
4) Or, instead of replacing the fuses and holders, would I be farther ahead to install a fuse box under the console? The boat is equipped with a fish finder and bilge pump and I may want the flexibility to add additional accessories in the future.

Click to expand...

I personally don't like in-line fuse holders... they are bulky, messy, and hard to get at often times... I would suggest doing away with them all, and either get a fused switch panel, or a fuse box/ individual switches... keeps everything in one place, easy to change out if a fuse blows and a lot less mess.

Brian_in_Waterford said:

5) I assume the plastic box is for the battery. Is it supposed to be fastened down in any way or does the battery just rattle around free?

Click to expand...

No it shouldn't rattle around it should be fastened (see below for answer).

Brian_in_Waterford said:

6) Finally, I've seen a couple of posts that mention the Universal voltage regulator. Would it be a good idea to replace my (potentially damaged) regular with the Universal? How would I test my regulator to see if it's properly working?

Thanks much! Sorry about the long post.

Click to expand...

You will need a voltmeter that can be hooked into the hot side of the system and check your charging voltage... one of the most necessary gauges (IMO) besides a tach, is a voltmeter on the dash... but it's optional

Brian_in_Waterford said:

In the meantime, I'm trying to decide how much electrical work to take on at the beginning of the project. Shall I repair what I have or gut everything and re-do?

Right now, I'm leaning toward repairing what I have so I can focus on replacing the deck and maybe (gulp!) the transom. Then, after I get the boat in the water, I can evaluate what modifications and enhancements I want (and can afford) to take on.

Click to expand...

This may or may not be true... depending how bad the PO fubared up the electrical system, you could spend a LOT of time diagnosing it, when for speed's sake it would be simpler to just re-wire it... Just something to consider... wire itself doesnt cost all that much, and sometimes its better starting new so you know what you have... I gutted mine and did a fresh wire job.

Brian_in_Waterford said:

In the short term, it sounds like I need some sort of way to fasten down my new battery. If you look at the pic in my original post, I have a plastic battery-shaped box that came with the boat. There isn't an obvious way to attach it to the hull, so I am looking for advice.

Click to expand...

It appears as if your battery box is missing the lid or is a lidless style... I dont like these because condensation, water drips, etc. can fill the box up with water, then your battery is sitting in a bathtub... I prefer the types with lids that keep the battery dry.

there is a selection of them here:
Battery boxes

As for the way to hold them down, there are a couple of options, you can get a tray that screws into the bottom of the hull/deck, then a battery hold down fastens to the tray, or a strap that goes through the some cleats you screw down that just wraps around the battery and box. Some examples here:

Battery Hold downs

I'll sketch up a basic diagram for you and post it in a few minutes.

/edit - also if you click the link in my signature for my rebuild, you can see how I laid out my new electrical system (its on the 2nd page). this may help to give you some ideas.

Re: Basic Electrical Repair - '85 Bayliner

Thank you everyone. All the replies have been a huge help. For cost and time sake, I decided to repair what I have for now. Upgrades will have to come later.

I screwed the battery box to a convenient stringer, dropped in the new battery, crimped on a new fuse holder, cleaned off all the old leads, hooked everything to the proper posts and, voila, the nav lights and fish finder are now working (no fish were detected in my garage ). The second positive and negative leads appear to go to the bilge pump. I need to head back to the store for an 18 gauge fuse holder to go with this wire - once I have it I should be back in business with regard to the battery.

I tried the starter and got nothing, so my next task will be to untangle the rats' nest under the console!

Re: Basic Electrical Repair - '85 Bayliner

Brian_in_Waterford said:

(no fish were detected in my garage ).

Click to expand...

I never get any readings on my sounder in the garage either, unless I throw a fillet on the floor. Perhaps we should consider stocking?