Mercruiser 470 Charging Fix

[Blazeracer]

Ok, well I got to deal with a melted regulator and about 18 volts running through my boat the other day. Fortunately the only thing that got hurt appears to be the electric fuel pump. I've done a lot of reading and tried something on a whim today that cost $40 and probably fixed it for good. No alternator kit needed.

From what I gather, the stator set up on a 470 is quite reliable. It is nothing more than magnets spinning around each other which generate an alternating current. Well, the old Fords used an external voltage regulator that has a built in rectifier, just what the stator needs to make it useful. Oreilly Auto Parts has the Ford external electronic regulator under part number F400 for $38.

The two leads that come out of the stator will connect to the F and S leads, the red NON SWITCHED wire will go to the A lead and the I lead will connect to any switched wire. I used the one on the starter solenoid since it's in close proximity. I just did it for $38 and my charge holds ROCK STEADY at 12.8 volts. Wha-Laa

Make sure you use weather proof connections and this is probably not good for salt water, but I only use my boat in Dallas area lakes.

Oh, the original regulator is still in place with all the wires removed. The Ford regulator is bolted on top of the Mercruiser regulator which kinda hides it.

No alternator, no charging nightmares, $38.....

 

[nola mike]

Re: Mercruiser 470 Charging Fix

huh. interesting. i'm having intermittent regulator issues, i'll keep it in mind. i'd be interested in the "non-marine/electrical part" aspect of this.

 

[NHGuy]

Re: Mercruiser 470 Charging Fix

I too would be concerned with using a non marine part. If it ain't marine, it ain't explosion proof. You save the cost of a repair or reman at risk of becoming a statistic.
Maybe you can get a marinized external voltage regulator. But don't leave that one in there, please.

 

[bruceb58]

Re: Mercruiser 470 Charging Fix

I just did it for $38 and my charge holds ROCK STEADY at 12.8 volts. Wha-Laa..

Not going to be outputting much current into a battery at 12.8V. VERY LITTLE!

 

[Wilbuc]

Re: Mercruiser 470 Charging Fix

Blazeracer - Thanks for the cool information. Do you happen to have any pictures of this setup and how you mounted the regulator?
Thanks again

 

[timw586]

Re: Mercruiser 470 Charging Fix

Blaze,
My regulator went up in smoke yesterday and that is the exact fix I was planning for mine. Have you tested it anymore since installation? Im not too concerned with it not being a marine grade part, as it shouldnt be below water. My coil, distributor cap, rotor, spark plug wires and fuel pump and any other part i can imagine all come from the local auto store and are car parts.

 

[rjwoodrome]

Re: Mercruiser 470 Charging Fix

as for the water proofing, it not as important as the possable spark risk that is present. if this regulator is sealed in an epoxy. then it is probably a more trust worthy item. I too own a 470 and am curious as to the final outcome of your rig.

 

[HT32BSX115]

Re: Mercruiser 470 Charging Fix

I just did it for $38 and my charge holds ROCK STEADY at 12.8 volts. Wha-Laa

Not going to be outputting much current into a battery at 12.8V. VERY LITTLE!

Um, I am somewhat at a loss understanding why you just ignored what Bruce said above.....

The terminal voltage of most lead acid batteries is about 12.5V, What makes you think that 12.8 volts (which may be less considering the error of most el-cheapo DVMs) is going to even charge your battery at all?


I'm not getting something here......


The charging system that Mercury used on the 3.7L series of engines, is the absolutely the worst system ever designed for anything.

The only reliable "fix" is an after-market external alternator with the regulator built-in.

 

[bomar76]

Re: Mercruiser 470 Charging Fix

Im not too concerned with it not being a marine grade part, as it shouldnt be below water. My coil, distributor cap, rotor, spark plug wires and fuel pump and any other part i can imagine all come from the local auto store and are car parts.

LOL...and I take it you are bragging about this?

You have no idea about what dangers are involved.
There is noting about this that is safe, legal, or sane.

 

[HT32BSX115]

Re: Mercruiser 470 Charging Fix

LOL...and I take it you are bragging about this?

You have no idea about what dangers are involved.
There is nothing about this that is safe, legal, or sane.

No Problem......it only matters when the boat goes "Kaboom" with the neighbor kid in it. Then the neighbors lawyer will be bragging about the easy "kill"!!

(Pun intended!!)

 

[nola mike]

Re: Mercruiser 470 Charging Fix

The charging system that Mercury used on the 3.7L series of engines, is the absolutely the worst system ever designed for anything.

The only reliable "fix" is an after-market external alternator with the regulator built-in.

eh, they seem to be as reliable as an alternator. just more expensive/complicated to replace, and sensitive to overheating...i'm still on my original setup.

 

[actaeon9]

Re: Mercruiser 470 Charging Fix

If you can at all possibly afford the alternator conversion I would recommend it to anything else...that's why the industry went in that direction...I know that doesn't really answer your question, and I'm all for saving money in a bind and fixing the problem (probably more than I should) but this system is just not one that anything other than "Right" will work with...

Alternator Conversion and 4" Heat Exchanger are two upgrades for my 3.7L that I would consider MUST haves IMO..


HTH

 

[HT32BSX115]

Re: Mercruiser 470 Charging Fix

eh, they seem to be as reliable as an alternator. just more expensive/complicated to replace, and sensitive to overheating...i'm still on my original setup.

Your mileage may vary...... The majority of them had enough problems to warrant a change. There's still OMC 460s running out there in radio land but If I had one I would change it before it died.

I suppose one could design a bullet proof regulator for that rotor/stator combination.... to eliminate the very poorly designed water cooled original.

Maybe the newer ones are better. but when you have to pay over $400 for just a simple solid state regulator and over $200 for the stator switching to something more reliable that costs a fraction of the above, is just a better idea.

 

[JHarrsch]

Re: Mercruiser 470 Charging Fix

Has anyone actually tried this?
I could not find Regulator F400 on O'reilly's site.
There is an R400 regulator for $21.99.

 

[nola mike]

Re: Mercruiser 470 Charging Fix

and i'd still like to know what about it would make it a bad idea in a boat--what about the voltage reg would make it prone to explode? it doesn't spark or anything--it's just like any other electrical connection on the engine, i think.

 

[bruceb58]

Re: Mercruiser 470 Charging Fix

and i'd still like to know what about it would make it a bad idea in a boat--what about the voltage reg would make it prone to explode? it doesn't spark or anything--it's just like any other electrical connection on the engine, i think.

To me it wasn't the explosion part. It was that he could only get 12.8V out of it. That won't charge a battery very much.

 

[nola mike]

Re: Mercruiser 470 Charging Fix

To me it wasn't the explosion part. It was that he could only get 12.8V out of it. That won't charge a battery very much.

no, but i'm not sure how accurate that 12.8v is. if the regulator is working, it shouldn't throttle down the voltage that much. maybe that was what the gauge was reading or whatever. if it isn't a safety issue, i'm willing to give it a shot for $30.

 

[nola mike]

Re: Mercruiser 470 Charging Fix

quick google search looks like a TON of fords used external voltage regs.
this one happens to have the correct labels. can anyone think of why this WOULDN'T work? seems like a simple/ingenious idea...

 

[fmalott]

Re: Mercruiser 470 Charging Fix

i got a 1983 THUNDER CRAFT 470 motor and the voltage regulator over charges battery so do i replace with alternator or do i use this $30 part i want to be a safe as possible this my first I/O

 

[mtp9302]

Re: Mercruiser 470 Charging Fix

To me it wasn't the explosion part. It was that he could only get 12.8V out of it. That won't charge a battery very much.

Yeah, isn't this similar to a car where the battery should read 13.5 - 14.5V when the engine is running?