Need advice with power voltage return for Mercury 200HP Saltwater EFI

[scisgr8]

Need advice with power voltage return for Mercury 200HP Saltwater EFI

If anyone can give me advice it would be very much appreciated. The outboard is a 2001. Last year I was having problems with my starter hanging up and staying on and killing my batteries. I replaced the starter solenoid or relay switch and that has seemed to correct that problem.

Now something is killing my batteries. The panel is showing 12-13 volts when the key ignition is switched on and or when the engine is running. My neighbor told me a good way to test is to start the motor and then unhook the negative cable to each battery and test. When I do this the engine shuts off. His advice is that there is something wrong with my stator because the engine should continue to run and supply enough power to keep it running. Can someone give me some advice on this and next steps before I have to take this engine and have it serviced?

Thanks,

TM

 

[j_martin]

Re: Need advice with power voltage return for Mercury 200HP Saltwater EFI

Disconnecting a battery while the engine is running is very bad advice. Don't do that again.

It looks like you lucked out and the battery charging system is not working. Saved you from burning out some expensive electronics. Odds are the voltage regulator is bad. I don't know which system you have, but if you can find the yellow wires coming out from under the flywheel and describe where they go, or even post a picture of it, we can go from there.

hope it helps
John

 

[scisgr8]

Re: Need advice with power voltage return for Mercury 200HP Saltwater EFI

j_martin, thanks for your reply - I'm posting the pics below and hope this helps.

There are 4 yellow wires running out of the stator or at least what I call the stator, the flywheel. 2 of the wires connect to what looks like some sort of electrical relay and the second set of two yellow wires connects to what looks like a second eletrical relay. Could these relays be bad? Are these relays? What should I call these parts, I'm not sure....... They are square about 1/2" thick and maybe two inches width and height.

Thanks in advance for any further advice or recommendations from any of you out there.

 

[j_martin]

Re: Need advice with power voltage return for Mercury 200HP Saltwater EFI

That's a dual regulator 40 amp system. Each of those devices are a 20 amp regulator. The yellow wires are AC from the stator to the regulators. The red wires should be connect to battery, probably at the starter solenoid. One grey wire drives the tachometer, the other one is not used.

If you disconnect each pair of yellow wires and put an AC voltmeter between them, they should yield about 15V per 1000 rpm. Resistance (engine not running) between the two yellows in a pair should be less than one ohm. There should be no continuity between any yellow wire and ground, and between a yellow of one pair with a yellow of the other pair. That proves the stator is OK.

I suspect both regulators are burned out. Not uncommon. Another common fault is for the connections of the yellow wires to overheat and open up. I usually replace the bullet connectors with a soldered splice.

Your battery voltage should go up to near 14V when the engine is running. If either regulator was working, it would.

hope it helps
John

 

[j_martin]

Re: Need advice with power voltage return for Mercury 200HP Saltwater EFI

What did you find?

Here's a link to my dual 20 amp system, and fixed connections.

http://forums.iboats.com/showthread.php?t=473187&p=3201370&posted=1#post3201370

 

[scisgr8]

Re: Need advice with power voltage return for Mercury 200HP Saltwater EFI

Sorry, it has taken me so long to get back on here but it has taken me this long to get my boat back in the water since last post.

I ordered two new voltage regulators and replaced the old ones, just as you described above and this has solved my problem. Now I've got one more problem that I need to investigate, my engine shuts down when it tops out or gets close to topping out. It's been doing this for the past season or so. Runs fine when running about 3/4 speed but when I run full throttle, it will completely shut off. I've replaced the in-line fuel filter and that didn't seem to do anything, so I'm going to search on here and maybe create another post.

Many thanks for your help, you probably save me in excess of $300 by your advice and me doing the replacements on my own following your advice and diagrams.