2014 Mercury 150 Alternator Test & Replace

On this video I go deep in detail on a boat with low voltage showing on the gauges and customer complaints of systems failing due to low charging.
I will show you not only the replacement of the alternator but all tests required to get to that conclusion. Hope this will help, all I ask is your help through your subscription in order to keep the channel growing and the useful information flowing, take care

[@johnrichardson1212]

One of the best repair video's for repairs that I have ever seen

[@hardrockminer-50]

I just did this to my 2014 150 hp Merc. Your video helped a ton! Thank you for putting it out. I ran the testing just as you instructed. No output on alternator. Had to wait a week for a new one to come in. The big dealer in town had one in stock but it was $200 more. Two comments: rotating the alternator into place was pretty difficult. I had to push with my feet against the alternator. When it did rotate, it stopped just a bit past the hole but was easy to line up. The torqueing of the bolts takes more uuumph than I imagined to get the 36 ft lb torque. Tested on completion 13+ bolts. Perfect.

[@us4marine]

Thank you Hardrock for your positive fed back, it really helps. Take care 👍🏻

[@WrathoflinX]

My 150 Mercury same problem. New alternator just came in and gonna change it today 👍 great video

[@hardrockminer-50]

Me too! Exactly the same conditions.

[@us4marine]

Thank you Wrath for watching, glad it was helpful. Take care. 👍🏻

[@reneclaudio5089]

Pete un abrazo desde PR siempre dándonos cátedras de una mecánica organizada y eficiente y gratis gracias pair lo q haces brother agradecido por dedicar un tiempo para tus seguidores y lo q a ti te costo aprender enseñarlo gratis

[@us4marine]

Como siempre agradecido amigo Rene, un abrazo. Cuídate

[@RobertEngelhardt-jk3mr]

my 150 Mercury is doing the same thing, thanks for the info, very helpful

[@us4marine]

Hi Robert, glad to help. Thank you for stopping by and for your positive comment Take care. 👍🏻

[@marcosdariomaldonadonoceda3846]

Buenas una consulta urgente que pasa si al poner la llave en contacto no me marcan corriente ambos cables rojo?

[@Sam-l2p5t]

Great video! Thank you for sharing. My alternator overheated and smoked when I turned the battery on, without starting the engine. Do you have any idea why this happened? I’m concerned about putting a new alternator in incase it happens again! My best guess is that I was charging two battery banks and accidentally switched them to emergency parallel and overloaded the voltage regulator, and now it overheats with just 12volts. Any help is appreciated!

[@shawnsinacola5835]

I have the same issue with mine, alternator was so hot, couldn’t touch it. I checked voltage from the battery to the automatic charging relay to the main Perko switch to the alternator. Nothing is grounded. Checked alternator output to ground, continuity, grounded, bad alternator. Just got my new alternator,🤞🏼, hoping that it takes care of the issue.

[@paulscozzari1787]

Around 10:54 you say the reading is unacceptable on the alternator at 12.4, 12.5. So what should have it been reading? How much higher than the battery voltage should the alternator read?

[@us4marine]

Hi Paul. When checking voltage on the alternator red stud connection (output) it should read 12.00 V to 12.50 V with the engine NOT RUNNING, now if the alternator is doing it’s job same reading with the ENGINE RUNNING should be 13.8 V to 14V depending how charged the batteries are, the lower the charged on the batteries the higher the reading even 14.8 V . Now if batteries are fully charged it should hoover around 13.5 to 13.8 unless at the moment of the reading you have a bunch of systems and accessories running. (Pumps, electronics, High powered transducers, Steering power assist pumps, heavy stereo and such.) Hope this helps. Take care and thank you for visiting the channel. 👍🏻

[@Elway1976]

Also should your motor pull any volts while its not running?I put a meter between my neg cable an battery an it shows 5 volts being drawn with the two pin connector undone an 9volts with the connector connected

[@dgc940]

So shop I work at has a merc 150 4stk In the shop that all 4 of us guys have been discussing. its way over charging up to 15v and toasting alternators. In a matter of a day. New batteries with a new alternator it shows 13.5-.7 BUT by end of few hrs run time its 15-16 volts and a ruined alternator. Any Ideas? merc tech line is not much help. Merc keeps sending alternators its under warranty.

[@floripasub1]

Great explanation!! Thank you

[@us4marine]

Thank Flori for your kind words, your opinion matters. take care.

[@Elway1976]

Is the rectifier built in to the alternator?Mine is draining my battery an not charging but around the same voltage as this one was.

[@us4marine]

Thank you sir, sorry for the delay in responding, I’ve been with my head in other things, but will try to keep it up. Thank you.👍🏻

[@izaquielfelix3942]

Parabéns, muito bem explicatos todos os detalhes. Isso que estava procurando!!

[@us4marine]

Izaquiel, muchísimas gracias por tu comentarios positivos y por ser parte de este canal. Recibe un abrazo. Cuídate 👍🏻

[@piranhafranky]

Now what if key on that second red wire doesn’t show battery voltage?

[@EasyMove-o9z]

Same to me .bought new alternator no reading in output at all

[@rickfascinato9684]

So helpful,thank you

[@us4marine]

Thank you Rick for your positive comments and for sharing your opinion, it truly helps. 👍🏻

[@ericrose5039]

Can't get a decent alternator on a mercury 150. Mine is a 2020 was pulling 4 amps with everything off, only giving me 10 volts at full throttle. It's fixed now but it was a bad alternator

[@AchikSarih]

Merci beaucoup ❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤

[@us4marine]

Je t’en prie.👍🏻