Alternator wiring?

[Calais]

I made a similar post awhile back and some of you tryed to help me out...(Thanks again).
I have a Mando alt that i am trying to convert onto a 3.7 4cyl mercruiser.
I have gotten a few wiring plans from the forum,but they are not the same wiring details...?

I Don't feel like buying another starter etc...By trial and error so if anyone would be patient enough to lead me through the wiring process,I would be forever in your debt..

PS...this is all new to me,so its a learning experience!!!!

 

[Bt Doctur]

Re: Alternator wiring?

See if 4C-3 in this link helps.The mando uses a sense and excite lead. The red/purple lead reads the battery voltage and the purple is a "switched 12V" hookup(to the + side of the ign switch)
A GM Single wire would bew a lot easier to work with.
http://www.boatfix.com/merc/Servmanl/18/18C4R2.PDF

 

[Don S]

Re: Alternator wiring?

I have a Mando alt that i am trying to convert onto a 3.7 4cyl mercruiser.
I have gotten a few wiring plans from the forum,but they are not the same wiring details...?

The big problem you are having is that the 3.7 (aka 470) NEVER, and I mean NEVER came with an alternator. So there are no "wiring diagrams" for what you want, they just don't exist.
What you need to do is disable, disconnect, and dead end the wiring from the original system, then rewire to the new alternator.
The first thing you have to do is mount the alternator and get a belt on it, and not have any of the terminals of the alternator touching the block or head of the engine. Do you have that part done already? If not, do that first. That is the hard part, wiring is easy and I could make you up a wiring diagram easily. When you are ready for it.

 

[Calais]

Re: Alternator wiring?

The big problem you are having is that the 3.7 (aka 470) NEVER, and I mean NEVER came with an alternator. So there are no "wiring diagrams" for what you want, they just don't exist.
What you need to do is disable, disconnect, and dead end the wiring from the original system, then rewire to the new alternator.
The first thing you have to do is mount the alternator and get a belt on it, and not have any of the terminals of the alternator touching the block or head of the engine. Do you have that part done already? If not, do that first. That is the hard part, wiring is easy and I could make you up a wiring diagram easily. When you are ready for it.

The alternator is all set up and ready to go.I have an orange wire from the starter to the alternator,(but not hooked up).The rotor has been taken out so there are no wires coming from it anymore.The alternator has a purple wire,and a red wire.It also has a condensor that is wired to a bolt...Now there is another bolt with shield washer on it....

Hope this helps.

 

[Bt Doctur]

Re: Alternator wiring?

That connection is where the Orange wire should go, the sense lead can also be hooked there.The excite goes to a switched source,ign switch preferred.

 

[Don S]

Re: Alternator wiring?

Is this the back of your alternator?

 

[Calais]

Re: Alternator wiring?

Basically the same..Mine might be older...
Batt output,the two cables.No tach,light etc..
I had posted a couple pics a while back..

http://forums.iboats.com/showthread.php?p=2597962#post2597962

 

[Calais]

Re: Alternator wiring?

Ok it took a while ,but I finally got some time to try wiring the alternator up ...
When i went to put the orange wire on the bolt where the short wire from the regulator or condenser is(batterie output)? It made an awful spark.I don,t think it liked it.

Am I trying to wire it at the wrong spot?

 

[Don S]

Re: Alternator wiring?

Now that I see yours, you have a completely different Mando, not what I pictured, so don't even try to hook it up the same.

Here is one I found in the mid 80's 3.0L manual. It at least looks like yours.

 

[Calais]

Re: Alternator wiring?

Thats Great Don...Thanks and i'll try hooking it up...excite to igniton ,orange to starter,and sense...?
Should i run a ground wire from the motor to the alternator...?(The bracket is new so would it be ground enough?)

Thanks again for your time!

 

[Calais]

Big Thanks!!

Big Thanks!!

I just want to thank Iboat staff who helped me out with the alternator problem I was having...Wired it like you showed me and I',m charging between 15 and 14.5 volts on both batteries..

Once again A big thumbs up

 

[HorizonblueDK]

Re: Alternator wiring?

Interesting.

I'm connecting an old style Mando alternator on a 4.3 engine that came with no wiring harness.

As far as I understand, the excitation lead only draws current until the alternator starts charging. So if you cut that wire (purple) and install a warning light here, it would illuminate when the ignition is switched on, and turn off when the alternator starts charging?

 

[BEARMAX]

Re: Alternator wiring?

is there any way to do a budget alt converion on my 3.7 ie junkyard parts.local marinas want $700 for the kit

 

[Bt Doctur]

Re: Alternator wiring?

either the kit or find a donor boat with one.

 

[Don S]

Re: Alternator wiring?

You guys need to start a new thread OF YOUR OWN, then maybe someone will see them.