Merc 90hp Outboard Charging

[ezgo]

If the outboard isnt charging the battery do I have to replace the voltage regulator/rectifier. Does the selinoid play a role in it also. Thanks

[CatFan]

If the outboard isnt charging the battery do I have to replace the voltage regulator/rectifier. Does the selinoid play a role in it also. Thanks

It could be several things, but probably not the solenoid. What year and type of motor?

Loose battery cables, a bad battery, bad stator/alternator, low battery electrolyte or a bad reg/rec can all cause charging problems.

I'd suggest you fully charge the battery, then get a volt meter and measure the battery voltage with the engine off. You should see about 12.65V or a little more, depending on the battery type. Then, with the boat in the water, throttle up to about 2500 RPM and measure the voltage again. You should see a jump up to something between 13.3V and a little less than 15V. Anything outside that range indicates a problem. High voltage is probably the regulator(s). Low voltage could be stator or alternator, or the regs as well.

If that part checks out, it's probably the battery. Either try a known good battery or have yours tested.

[Shellback]

If you mean the starter solenoid, then no it shouldn't affect the charging. Parts for the charging system are very expensive If you aren't sure of the problem, an hours labor charge for diagnosis at a dealership might be a good investment. Check all your connections and ground, there may be corrosion causing the problem.

[Barnacle Bill]

It all depends on what motor you have. Charging circuits on older motors are very simple.

[ezgo]

It is a 2003 two stroke, I have been up all night doing alot of reading, trying to learn and I need to get the muffs on it. Can I check it straight from the battery or do I have to check it inside the engine. I will check all of the connections and clean and tighten anything I see that could be a potentual problem. Lets say the the voltage reg is bad, instead of paying a hundred bucks for one, can I go to the local auto parts store and get a five or six blade voltage reg and use that. Merc wants around a 176 bucks or so. Thanks

[Barnacle Bill]

You can check it at the battery. Unfortunately you have to use Merc parts as you have a combination rectifier/regulator.

[jiggshooter]

take the guess work out and take it garage because it you get electrial parts they are usually no returns

[ezgo]

Well I put the muffs on it today and cleaned all battery terminals and wires. Started the engine and was fooling around with the muffs making sure they were on right and took it up past 2000 rpm and I had 14 volts. I then shut the motor down and let it sit for a minute and checked the battery without it running and had 12.64 to 12.77 volts. Then I started the motor back up and took the tack back past 2000 rpm and had 14.1 to 14.2 volts, I would think it is charging the battery now.

[Barnacle Bill]

Sounds like you are in good shape. Were you having a problem or just wondering?

[ezgo]

Sounds like you are in good shape. Were you having a problem or just wondering?

Yea the battery wasnt up to its full state when I started cranking it, it sounded real slow and then it went out and all of my graphs went out. I turned them back on and gave it one last chance and it turned over slow, but it did start. I idled the motor for a few minutes and turned it off and checked the battery with my little minkota battery meter and it said 2/3 full. So I continued to fish and when I was done I put the boat on the trailer and checked the battery when I got home and it was only 1/4 charge left on it. So I took the battery in for a test and it was still good, it is only a year and a half old. This lead me to beleave that I had a charging issue. The negative side was dirty and discolored but not caroded real bad.