mercruiser 470 alternator conversion no start wiring question

[Don S]

Re: mercruiser 470 alternator conversion no start wiring question

Don't run it again just yet, you may be trying to charge through ignition switch...... NOT Good.

Removed wiring diagrams, they were wrong.

 

[Don S]

Re: mercruiser 470 alternator conversion no start wiring question

Ok, I was telling you wrong. So don't do anything with it just yet, the alternator is wired wrong.

 

[Don S]

Re: mercruiser 470 alternator conversion no start wiring question

Ok here is the correct information.

The red wire going from the old voltage regulator to the solenoid is the one that gets removed and discarded.

The Red/White wire coming from the instrument panel ammeter that went to the + terminal of the regulator is now the wire you want to hook to the alternators main output.

Now all will work as it should.

The wiring diagrams I posted earlier were correct and only showed the old wiring, not the new wiring. Here they are back.

 

[olazabel]

Re: mercruiser 470 alternator conversion no start wiring question

Don- Those wiring diagrams match my boat perfect. Thanks.

Originally, I thought to connect the alternator power wire to red/white, but then I read in old threads to wire the alternator directly to the battery or solenoid because the new alternator would put out more power than the original stator and could burn up the gauges, wires, or dash.

The instructions that came with the kit also said to wire the alternator to the solenoid

Wiring the alternator directly to the red/white wire seems to make sense (since the power from the old stator ran through it), but do I need any connection from those wires to the solenoid like the old regulator had?

It seems so simple, just dont want to burn up my wires or boat for that matter.

 

[Don S]

Re: mercruiser 470 alternator conversion no start wiring question

Don- Those wiring diagrams match my boat perfect. Thanks.

Originally, I thought to connect the alternator power wire to red/white, but then I read in old threads to wire the alternator directly to the battery or solenoid because the new alternator would put out more power than the original stator and could burn up the gauges, wires, or dash.

The instructions that came with the kit also said to wire the alternator to the solenoid

Wiring the alternator directly to the red/white wire seems to make sense (since the power from the old stator ran through it), but do I need any connection from those wires to the solenoid like the old regulator had?

It seems so simple, just dont want to burn up my wires or boat for that matter.

Might take a look, I would bet all those instructions are for motors with BIA wiring and Voltmeters on the dash, not ammeters and the older wiring.

 

[olazabel]

Re: mercruiser 470 alternator conversion no start wiring question

Don- First, THANKS A LOT for taking time out of your Sunday to help me out with this. I really appreciate it.

Here's the link to an old thread on the topic:

http://forums.iboats.com/mercruiser...ves/mercruiser-470-wiring-problem-255034.html

If you have time could you read the four or five posts and tell me what you think?

Iguess the next step is to try hooking the alternator output directly to the red/white wire (to the ammeter) and see what happens. If I wire it any other way, the 40 AMP circuit breaker will be out of the loop.

And no jumper to the solenoid needed, right?

 

[Don S]

Re: mercruiser 470 alternator conversion no start wiring question

Stick with your original setup, and that other thread. I'm looking at something wrong and not sure what. Plus I'm trying to watch the race now.

 

[olazabel]

Re: mercruiser 470 alternator conversion no start wiring question

Ha Ha. OK. ALOHA for now.

 

[olazabel]

Re: mercruiser 470 alternator conversion no start wiring question

Anyone else want to ring in on this? Old style voltage regulator, ammeter in the dash,

Whats the best wiring setup for the Alternator conversion???

 

[Don S]

Re: mercruiser 470 alternator conversion no start wiring question

Here is a wiring diagram from a Chevy V8 using the single wire alternator like you are now installing. It goes to the red/white wire. Fords did the same thing.

View attachment #2 Eng & Drives 74-77 206.pdf

 

[RammaR]

Re: mercruiser 470 alternator conversion no start wiring question

Olaza -- glad you started this thread as it's making me reconsider how mine's configured. I got a 105-amp marine alternator off of ebay and we fabricated the bracket. I was also concerned about running that much current through the small red-white wire and up to the dash, which is why we connected it directly to the solenoid post with the battery lead. Seemed like a potential melted wire / fire hazard without going that way. But I guess if it pulled more than 40-amps the circuit breaker would trip.

So the way I have it now, the alternator is by-passing the 40-amp circuit breaker and going right to the battery / starter solenoid. My thinking was that with the red-white wire still connected to solenoid the rest of the boat is protected by the circuit. I need to go read that other thread, but I'd like to convert the ammeter to a voltmeter in the dash. Have you considered doing the same?

Thanks!

 

[Don S]

Re: mercruiser 470 alternator conversion no start wiring question

Getting rid of the ammeter is the best thing you can do. After 78, Merc never used them again. All it does is rob your charging system of amperage. Many just hook the red/white wires and the red wire at the ammeter together and get rid of that stupid gauge.

 

[olazabel]

Re: mercruiser 470 alternator conversion no start wiring question

Olaza -- glad you started this thread as it's making me reconsider how mine's configured. I got a 105-amp marine alternator off of ebay and we fabricated the bracket. I was also concerned about running that much current through the small red-white wire and up to the dash, which is why we connected it directly to the solenoid post with the battery lead. Seemed like a potential melted wire / fire hazard without going that way. But I guess if it pulled more than 40-amps the circuit breaker would trip.

So the way I have it now, the alternator is by-passing the 40-amp circuit breaker and going right to the battery / starter solenoid. My thinking was that with the red-white wire still connected to solenoid the rest of the boat is protected by the circuit. I need to go read that other thread, but I'd like to convert the ammeter to a voltmeter in the dash. Have you considered doing the same?

Thanks!

Ramma-replacing the ammeter with a voltmeter was my original plan, and I was planning to tape off the red/white wire until I realized that without it the 40amp circuit breaker wouldn't be connected to anything. Can't believe I'm spending this much time deciding what to do with one wire.

Right now, I have the alternator connected to the solenoid like the picture you sent and the red/white wire disconnected and taped off.

Does your ammeter work with the red/white wire hooked to the solenoid?

 

[olazabel]

Re: mercruiser 470 alternator conversion no start wiring question

With the alternator power wire connected to the red/white ammeter wire, Will the 40AMP circuit breaker will protect the wires and gauges in the dash?

 

[olazabel]

Re: mercruiser 470 alternator conversion no start wiring question

Getting rid of the ammeter is the best thing you can do. After 78, Merc never used them again. All it does is rob your charging system of amperage. Many just hook the red/white wires and the red wire at the ammeter together and get rid of that stupid gauge.

I'm with you on that Don. I don't need the ammeter, but do I need the red/white hooked up for the circuit breaker? Or can I just leave it taped off and be done with it???? Maybe it doesn't matter.

 

[RammaR]

Re: mercruiser 470 alternator conversion no start wiring question

Does your ammeter work with the red/white wire hooked to the solenoid?

I do get a reading at higher RPM's, but overall it's useless. I'm hoping to use as much of the existing wiring as possible when I replace it with an voltmeter, but that will be a fall / winter project when I re-gauge the dash. So I thought the red-white wire would still be used then, but I could be wrong.

Good luck.

 

[RammaR]

Re: mercruiser 470 alternator conversion no start wiring question

I tried disconnecting the red-white wire from the solenoid this morning and she wouldn't crank at all. It sounds like the condition you first had with yours. As soon as I reconnected the red-white it starts right up. Did you do anything else with yours to get it to start without the red-white wire going up to the ammeter? I may just leave it as is and disconnect the ammeter itself.

Thanks.

 

[olazabel]

Re: mercruiser 470 alternator conversion no start wiring question

Hey Ramma.

No, I didn't do anything else. Once I got the boat to start, It would start and run with the red/white wire connected to the solenoid, or disconnected and taped off.

I took the boat out, and tried it both ways. It didn't seem to make any difference to how the batteries charge, or how the boat runs. Right now, I have the red/white wire hooked to the solenoid because I want the 40 amp breaker hooked to something (even though I'm not sure its protecting anything)

I did install a voltmeter last week. It was real easy. All you need is a hot wire and a ground. I drilled a new hole in the dash, and tapped into the cigarette lighter wires. It works good.

I was going to remove the ammeter, because it doesnt work anymore, but when I looked at the wiring, I decided to just leave it alone.

So... right now, I have everything wired the way that you originally suggested. Seems to be working well. If anything changes, I'll let you know.