Not Enough Volts?

[barak888@msn.com]

I have a 200 Merc black Max, I think its about a 1985. When the engine is running, my volt meter shows me runnig at about 11.9 volts. I was told it should be at around 14 volts to charge the battery. I changed the voltage regulator, and that did'nt fix the problem. Any help or suggestions would be much appreciated. Thanks

 

[The Marine Doctor]

Re: Not Enough Volts?

Some V6 product have 2 voltage regulators.<br /><br />Check for that first.<br /><br />Does the battery accept charge?<br /><br />Hopefully you are not left with changing the stator.<br /><br />TMD

 

[Skinsk]

Re: Not Enough Volts?

Have you tried checking the voltage with a true multi-meter.. I have found merc voltage meters to be not of the highest quality/accuacy.<br /><br />Scott..

 

[barak888@msn.com]

Re: Not Enough Volts?

The batteries I am using are brand new. I can only see one voltage regulator, but there is another three prong device? I think its called a rectifier. Could this little thing be the problem? It seems to be a part of the whole electrical system. <br /><br />What is the "stator"? And is it a big deal to chang? I apologize for all the questions, but working on a boat is a bit new to me. <br />Thanks for your time. I appreciate it. <br /><br />John

 

[The Marine Doctor]

Re: Not Enough Volts?

Do yellow wires run to the small box? IF so this is likely the problem.<br /><br />TMD

 

[barak888@msn.com]

Re: Not Enough Volts?

Yes there are yellow wires that run to a small semi-square metal box. This has three prongs on it,wires are connected to all three, and a positive symbol in the lower left corner. My voltage regulator(which i just replaced)is mounted on the top of the engine, on the backside of what looks like a fly wheel. Are the yellow wires not supposed to be connected to this? or are you saying that the small three prong metal box may be the problem?<br /><br />John

 

[The Marine Doctor]

Re: Not Enough Volts?

The small box might be the problem.<br /><br />TMD

 

[RatherBFishing]

Re: Not Enough Volts?

I had a very similar problem with my boat. I had marginal voltage (according to my sonar unit). I tried cleaning the battery contacts and that got me a little more voltage... was pushing 13 volts then. I pulled the positive cable off the battery and it looked like it had corrosion inside the connector. I cut off the connector and put on a new one and my voltage has been right up there at 14.1 to 14.3 volts.

 

[barak888@msn.com]

Re: Not Enough Volts?

I'll try these things this weekend. If cleaning or replacing the cables doesn't work, then I'll replace the rectifier. I'll let you know how it works out. Thanks for the good info. <br /><br />John

 

[rickdb1boat]

Re: Not Enough Volts?

First, check the rectifier<br /><br />

 

[barak888@msn.com]

Re: Not Enough Volts?

Many thanks for these instructions Rick. <br />You may have just spared me the cost of a rectifier. Quick question... If it isn't the rectifier, what are some other things I could look to as a possible cause? <br /><br />John

 

[JasonJ]

Re: Not Enough Volts?

I just replaced the rectifier on my Merc. Instead of spending a fortune, I just went to Radio Shack and bought a Bridge rectifier for $5 or so. Hooked it up, and went from no charging to 14 volts charging at idle. I gained 300 rpms as well, because the ignition system was getting more juice. I have used the Radio Shack rectifiers for every outboard I have owned, it works fine. All a rectifier does is take Alternating Current and convert it to Direct Current using diodes, which are basically one way valves for electricity.

 

[barak888@msn.com]

Re: Not Enough Volts?

Great.. If I choose to go the Radio Shack route, is there a specific type of bridge rectifier I should ask for? or do I just say give me a rectifier.

 

[ronmold]

Re: Not Enough Volts?

I think the 'Shack has a 25Amp unit w/bolt hole in middle. you must ground the - lug & solder to the leads. Run the + to red lead. must be bolted to metal for a heatsink and use silicone sealer on lugs to support them for vibration. Tach lead can run off one of the yellow wires. Also ohm meter will not read "0" when testing rectifier as the manual says, it will read 600 to 800 ohms one way and open the other.

 

[JasonJ]

Re: Not Enough Volts?

The Shack only has the one Bridge Rectifier. Its a little over an inch square, 1/4 inch thick, has four posts, and one corner has a small angle cut in it. That is the corner that has the + post. Ground the - to the engine, and hook up the AC wires to the other posts. You will probably have to install new terminals. Bolt the rectifier to metal (not the engine itself), use some dielectric grease on the metal to metal contact area to transfer heat, and enjoy the wonderful benefits of a chargings system for less than $5. Good luck....

 

[duck-n-pond]

Re: Not Enough Volts?

One thought, are your accessories connected to power via the ignition key???? If so, you may have to power them directily from the battery and connect a relay to the ignition because only small wires are run in the control cable (at least on my boat), and if you have accessorires running, this may drag the voltage down. I had read in my manual to never power accessories directly from the ignition for this reason. Also turn off or disconnect all accessories to see if one of the could be loading the system.

 

[barak888@msn.com]

Re: Not Enough Volts?

DasBoot and JasonJ: Thanks for the info. I'm on my way to Radio Shack. Hopefully this works <br /><br />Duck-n-pond: My accessories are connected through a small fuse box. My ignition does not have to be on in order to run my lights, fish finder etc...I use a switch to cut off power from the battery, and to switch between my trolling batteries and my starting battery. <br /><br />Thanks, <br />John

 

[barak888@msn.com]

Re: Not Enough Volts?

I was wrong! I do have some gauges that are backlit that come on with the key. I guess I just assumed otherwise. <br /><br />I replaced the rectifier with one from Radio Shack ($2.99). My volts didn’t change at all; I'm still at 11.9 to 12.0 ish. Is it as simple as me disconnecting these gauges, or are they attached to the ignition some how? <br /><br />I'm bummed; this isn't going according to plan....<br />I keep running into brick wall after brick wall...<br />If you can think of anything else (besides selling my boat) let me know. <br /><br />John<br />know.

 

[ronmold]

Re: Not Enough Volts?

Do you have another test meter? You might need to check voltage right at the battery to get the best reading. Your gauge might be off if you are taking current from the ignition circuit ( the gauge lights) If the motor is starting without you having to use a jumper the battery might be charging just fine. Best thing now is to run it up over idle (2000 RPM or so) and check the battery with another meter digital would be best.<br />good luck

 

[The Marine Doctor]

Re: Not Enough Volts?

If the regulator/rectifier does not solve the problem...the problem will most likely be the stator.<br /><br />TMD