Electrical issues

[wallydc2]

This is the second time that I have replaced the battery in my 1991 regal boat. Every time I try and restart it, it will not start. I installed a depth finder and I connected that to the ignition wire. That is the only change that I have made. Why my battery will not stay charged is the question?

The motor is a 3.0 mercruiser 1991, The alternator also tested OK. This is the second battery bought from Walmart that has been replaced in less than a year. Any help is appreciated.

 

[hard-3]

Re: Electrical issues

put an ammeter in series with the + battery cable and see if there is a current draw. A auto parts type replacement ammeter can be used to test with , just don't try to crank it or over draw the amperage of the meter. if there is current draw in the off not running position, start isolating things till threre is no current draw . A battery disconnect switch can cure this also. may be a compartment light on running down battery or some sort of drain.

 

[Don S]

Re: Electrical issues

I installed a depth finder and I connected that to the ignition wire.

You should not be hooking up a depth sounder (or any other electronics for that matter) to the ignition. They needs to be hooked to the accessory fuse panel.
If you are just tuning the ignition on, so the depth sounder works, you are also running the electric choke and power to all instruments and ignition.
Once you have the depth sounder wired correctly, start the engine and with a DVM hooked directly to the battery and engine running at around 1500 rpm, be sure the voltage shows around 14.5 volts. Then you know the alternator is charging. Are you sure the alternator belt is tight?

 

[bkdlays]

Re: Electrical issues

There are a few possibilities here


Your starter actually may be bad. It may be drawing too much, or the ground could be poor. Double check the connections for corrosion or a loose connection. You may only be getting a percentage of your battery power

Was your alternator tested by an actual tester? If the diodes burn out then the alternator can actually drain the battery. It could still put out power while running, but kill the battery when not running. You need over 14v output to charge your battery also.

You could have a draw from your depth finder, but thats unlikely. Disconnect it next time and you will know.

As someone else said, connect a meter inline to see if there is a draw.

Lastly, Walmart doesn't sell the highest quality batteries. I personally only use the best batteries I can buy. Optima, Interstate, Napa are decent marine batteries.

Good luck

 

[wallydc2]

Re: Electrical issues

1991 mercruiser 3.0l

When I installed the depth finder I hooked the red wire to another red wire. The ground wire I hooked to a yellow wire coming from the blower. Apparently this is wrong because when I turn the blower on the depyh finder stops working. I dont know where the accessory panel is, Don if you have a diagram that would be great. I also notice that when I hook the battery terminals up the CD player resests itself, I dont know if that could be the problem considering it has a detachable face. These little 3.0's dont seem to have alot of wiring to them. I cannot seem to get the battery to fully charge. Put it on the charger last night when I came home from work today a 5p, still not fully charged, maybe I am destroying batteries?? I will perform the electrical tests that you guys recommended once I get the battery charged a little bit if that is possible. Should I remove the alternator and have it tested? Could it be destroying the battery?

 

[wallydc2]

Re: Electrical issues

How do you put an ameter in series? Is there a diagram out there that shows a guy exactly what to do?

 

[bruceb58]

Re: Electrical issues

1991 mercruiser 3.0l

When I installed the depth finder I hooked the red wire to another red wire. The ground wire I hooked to a yellow wire coming from the blower. Apparently this is wrong because when I turn the blower on the depth finder stops working.

What is happening here is that you getting the ground through the blower. When you turn the blower on, your wire that you think is ground all of a sudden has 12V on it so you don't have a ground path anymore. You need to find a true ground. Near the fuse panel, you will see some posts with black wires hooked to it. That is where you need to hook up your ground.

 

[bruceb58]

Re: Electrical issues

How do you put an ameter in series? Is there a diagram out there that shows a guy exactly what to do?

You take the battery cable off of the positive terminal and bridge the battery cable to the battery post with the ammeter. The current will flow through the ammeter where it will get measured.

 

[wallydc2]

Re: Electrical issues

OK guys,

This is what I did, disconnected depth finder, disconnected stereo after tracing the wire for 20 minutes. I still get 12 volts with my DVM in series. Does that mean that something is still draming voltage? I fixed the issue with the depth finder by redirecting the ground wire. Intresting enough, it works without the ground wire attached to anything??? I have no idea what is going on here. I opened the panel to the stereo wires and disconnected the memory wire per the local boat store. The stereo will not work without the memory wire attached to the hot wire. Went back to the dash after tracing the wire as mentioned before, and it is on a dual connection that has a red wire connected to it that runs to the blower. Disconnected that and of course the blower will not work, but I still have current back at the battery while testing in series as suggested before. When I plug the connection back in, the blower works ONLY with the key on, because you have to push the blower switch, I suppose, but the stereo will still work without the key on and they are on the same switch connection???? Apparently I am still missing something. Regardless with everything but the nav lights and horn disconnected I still have current at the battery post. Any more suggestions would be appreciated.

 

[wallydc2]

Re: Electrical issues

I wonder, should'nt I see voltage even if the key is in the off position? Or should the key switch block the current flow? I am not an electrician, but very mechanically inclined thanks for all the suggestions thus far.

 

[Maclin]

Re: Electrical issues

What do you mean by "the dvm in series". Are you trying to use the dvm as the ammeter? The wires have to be able to carry the full load of the system. DVM test leads will not cut the mustard. An ammeter is a pretty hefty piece of work with large terminals for big current capacity wires.

 

[wallydc2]

Re: Electrical issues

I was under the impression that my DVM would do the job. I will go and purchase an ammeter if I need to. As said in the earlier post I am not an electrician but willing to learn.

 

[bruceb58]

Re: Electrical issues

Most DVMs have the ability to test current and many can test up to 10 amps. The positive lead usually needs to be moved to another input on the DVM and the dial of the DVM needs to be selecting the current mode.

For example, in this image the positive lead needs to be moved up to the empty input to measure 10A or kept in its present position to measure up to 200mA.

 

[chiefalen]

Re: Electrical issues

You have a inline fuse on the fishfinder? Should have came that way in the box.

Same with the stereo. I just installed a cheapo stereo in my boat. Long story with that,saltwater got it in the old location so i put the new one in the cuddy on a wall.

Disconnect everything but the starter and the tilt. Run down the wires to where there hooked to the boat. Not from the stereo or fishfinder side. Make sure any lights are off. Disconnect the blower also.

Than start your testing.

When you reattach do it one at a time. You can take power from the battery with a inline fuse. Use the neg. on the battery. Run all new wire, I know takes time. But when your done you would have done it right the first time.

You can install a battery cutoff. Just like in a previous post someone suggested.

One last thing nothing ever should be hooked to the ignition switch.

 

[Don S]

Re: Electrical issues

Since you really don't seem to understand electricity and how it works very well at this point, I suggest you download the 12Volt handbook (link below) and study it for a while before you hook anything else up.
http://www.motoren.ath.cx/menus/electrical.html

I'm also moving this over to the electrical forum for further wiring help.

 

[hard-3]

Re: Electrical issues

Don s. that boat electrical tutorial should be a sticky at the top. If most people read that , they would have a better idea of where to start troubleshooting . I would suggest that every boater should read it ,along with "why it won't start "
I thank you for this information and I'm sure the lurkers that come here for good info , do also. I am sure there are hundreds of people that read here and never post, that are helped through others misfortunes.

 

[Maclin]

Re: Electrical issues

Bruce,

I was concerned that the key may get turned on and draw some real amps and fry the test leads, but I guess the meter might fuse out before that. Also it is difficult to get test leads attached well enough to handle "real" current, that is where I was coming from. I have an old 12v ammeter gauge in my tool box just for that, it is hard to see smaller curent draws but you can still tell and it can handle the full system load if I need it to.

 

[hard-3]

Re: Electrical issues

I have 2 different ammeter set ups for testing one has battery clips for going directly to battery post the other has male spade clips to test fuse blocks

 

[Silvertip]

Re: Electrical issues

Ground wires are black. Follow them and you should end up at the ground buss on or near the fuse/circuit breaker panel. Ground your accessories there. Likewise, the fuse/circuit breaker panel is the spot to connect the power (red) wire.

 

[bruceb58]

Re: Electrical issues

Maclin,

I know that is what you were thinking. I probably should have warned him about that.

I have test leads with alligator clips all made up that I use for these types of tests.

Since his battery was going dead, he needs to see what is drawing off the battery when everything is supposedly off.