Rectifier

[jerry murray]

Think the rectifier on my 1988 Mercury xr4 150 hp is bad. checked battery and it measured 12v then cranked engine and there was no change. Tachometer is not working either. Voltmeter on dash showing just below 12v. Any other checks?

 

[Barnacle_Bill]

Re: Rectifier

You can test it according to your manual. Sure sound like there is a very good chance its bad.

 

[Boatist]

Re: Rectifier

I do not know your motor but on most motor there are many thing that can cause your problem. Could also be a voltage regulator or just a wire loose.
I think you may get more help in the mercury motor fourm.

 

[jerry murray]

Re: Rectifier

Sorry, but I do not fully understand where to post a thread. I posted this one in electric etc. Would like to know the proper procedure. Thanks for the help though. The manual has a long drawn out deal on checking it. I have been reading different threads on the rectifier and thought if your battery wasn't getting charched it was the rectifier or voltaage regulator. Didn't think this motor had a voltage regulator. Does it?

 

[Boatist]

Re: Rectifier

Some small motor with just a few amps output 3 to 6 amps may not have a voltage regulator. Most large motor with higher current outputs will have a voltage regulator.

The rectifer just changes the alternator output from AC Voltage to DC Voltage for charging the battery. On large motors with 15 to 30 amps of output will have a voltage regulator. If they did not then the battery would be way over charged and light bulbs would burn out and electronics burned up. Some here may know your motor but I think you will get more help in the Mercury Outboard Fourm.