MCM 170 3.7L Voltage SPIKES!!

[FluffyChicken]

I was out on the water last week and when i was cruising my volt meter was burried at what im guessing is like 20volts. My stern light burned out from it. I was wondering what causes this or if its normal. My volt gauge ends at 16volts and the needle was like a half inch past that. I've owned the boat for two years. It has done it in the past many times but has never caused any lights to burn out. Thats what made me stop and wonder what is going on. Thanks
Ken

 

[Bt Doctur]

Re: MCM 170 3.7L Voltage SPIKES!!

could be the so-called "water cooled regulator" .
unless you have a alt. conversion.then i`d have the internal regulator checked.if it`s the water cooled one, the do the conversion.

 

[FluffyChicken]

Re: MCM 170 3.7L Voltage SPIKES!!

That sucks. That part is pretty pricey. Can I keep running it like this or will this eventually mess up my whole electrical system?

 

[Bt Doctur]

Re: MCM 170 3.7L Voltage SPIKES!!

Well, if the reg. goes your pumping open DC voltage into the system. may go to 28Vdc i think.
this would fry all the electrical components. gauges, bulbs, electronics,overload the wiring,coil, battery,etc.

 

[ggallant]

Re: MCM 170 3.7L Voltage SPIKES!!

What year is the boat, or more spacific the altenator?

Most have internal regulator & recifire bridge, a few diodes.... not that hard to resolve .

Voltage is on thing - how many amps?

Made sure grounds to block & all wire connectors are clean and corrosion free. Use a silicone di-electric grease to keep them that way .

Check all light sockets for same corrosion and repair as required. shorted connections could draw excessively from altenator... showing the spikes .

A proper load test on Battery and altenator output at idle , and at speed (1500 rpm) and with all possible accessories on will reveal health level of altenator.

I had my stator (windings ) upgraded to 100 amps and smaller pulley to speed up the alt. on my boat . Love to help you if I can ... G

 

[Bt Doctur]

Re: MCM 170 3.7L Voltage SPIKES!!

This type of motor has a stator and magnet system,Pretty sure it can go 28VAC into the reg. 13.6 nominal output.
dosent even resemble a conventional alt.

 

[FluffyChicken]

Re: MCM 170 3.7L Voltage SPIKES!!

Yes it has a "stator" which is under the harmonic balancer. No where near a standard alternator. I'd love to get an alternator but the conversion kit is like 500.00.

 

[Laddies]

Re: MCM 170 3.7L Voltage SPIKES!!

Clean the regulator terminals and the battery terminals any dirty or lose connection will cause the type of spiking

 

[Don S]

Re: MCM 170 3.7L Voltage SPIKES!!

I'd love to get an alternator but the conversion kit is like 500.00.

If your problem turns out to actually be the regulator, that regulator, (from Merc) lists for 426 bucks.
That front pulley with the magnets in it also have a habit of loosing or breaking magnets, it lists for 459. Of course when those magnets break, it usually destroys the stator along with it, tack on another 225 dollars.
Along with all that burns up because of the high voltage, (lights, pumps, batterys, ign. parts etc.)
Add all that up, and that $500 conversion kit doesn't sound too bad.

Just another reason the 470 were disliked by marine techs. The techs are the ones that always get the blame for the cost of marine repairs being so high.

 

[rodbolt]

Re: MCM 170 3.7L Voltage SPIKES!!

also add about half the time you have to remove the engine to get clearence for the removal and installation tools and the cost goes nuts.
the AC side of the system is capable of something like 700 volts when opened. the DC side is something like 60 amps.
the regulator/rectifier tries to control all of it and make a usable fairly stable 13 volts or so.
at 16V your going to start burning up 12V electronics and boiling batteries.
there is a simple truth table about kirchoffs law of current and law of voltage.

 

[180shabah]

Re: MCM 170 3.7L Voltage SPIKES!!

there is a simple truth table about kirchoffs law of current and law of voltage.

He who has the current, makes the laws

 

[JoChek219]

Re: MCM 170 3.7L Voltage SPIKES!!

I don't think Iboats has them on there website but check them out first. But I do know Breezeworks.net sells alt. kits for about $200 or so for the 470's(3.7L) I put one on my boat last summer and has worked great and it a lot better then that watercooled voltage regulator and stator.... for the harmonic balancer just use a puller and take it off and make sure you get all of the magnets off and take off the stator and your good to go... that kit is a really simple install

 

[FluffyChicken]

Re: MCM 170 3.7L Voltage SPIKES!!

HOLY CRAP!!! THEY ARE ONLY 200 bucks. At breezeworks.net. THank you so much!!!. Thats awesome.

 

[wire2]

Re: MCM 170 3.7L Voltage SPIKES!!

The Breezeworks bracket kit is $89, and you can get a new 1 wire marine alternator on fleabay for $65, a reman for $50.

Just search "marine alternator"

 

[crazyinkc]

Re: MCM 170 3.7L Voltage SPIKES!!

i did the same thing on my 170. I bought a bracket kit from breezeworks and a feebay marine 65A alt. for 80 bucks shipped. The whole thing with shipping was less than 200. I did have to file on my bracket for the mounting ears on the long bolt abit but it was easy. I just wish i could have had the same luck with my Petronics kit. It ran for less than a mile and then the engine wouldn't rev over 1600 RPM. I had to swap the points back in on rough water. I waited to do the point eliminator until I got my charging system fixed. I left the stator and regulator in place and just disconnected the feed to the regulator so the stator would not build a field.