1998 Mercruiser 5.7 liter i/o, trying to put a new alternator on it. Don't know how to change from 4 wire alternator to this new kind.

[GatCat74]

1998 Mercruiser 5.7 liter i/o, trying to put a new alternator on it. Don't know how to change from 4 wire alternator to this new kind.

I bought the correct DB Electrical ADR0299 alternator for this engine but there is absolutely no instructions or a diagram or labeling on the alternator for + or-.
Right now the website is giving me errors for attaching any pictures

https://drive.google.com/file/d/0B0I...ew?usp=sharing


https://drive.google.com/file/d/0B0I...ew?usp=sharing

My boat has two black wires, one red wire, and one orange wire that were on the old alt. Does anyone know where these go on the new one? I just noticed this tonight when trying to install, there is a 1-800 for DB but I don't know if they'll answer till Monday. So if anyone knows.

 

[alldodge]

Howdy

You need to post some more times before you will be able to upload pics. Many have trouble getting info from DB and they have nothing online which will help as you have found. I found an older thread which has some info on it that may help if you can identify the terminals as listed. Maybe boatman37 can help, appears to be the only one that may still be hear

http://forums.iboats.com/forum/boat...3-replacement-db-electrical-alternator-wiring

 

[alldodge]

My best guess is your going to need a connector to plug into where the 2 pins are. Your Mando Alt connections

 

[GatCat74]

This helps a bit guys thanks, except the pictures are gone on that older post. I was looking at dusk last night and when I looked again this morning I noticed I got the colors completely wrong.

So coming out of the boat there is a black ground, a purple wire that was hooked up to "EXC", a red wire with a purple stripe that was hooked up to "S" terminal, and the orange wire hooked up to what I think is the positive charging post.

I've wired up guitars and car stereos but never an alternator.

 

[alldodge]

Black is case ground
Purple is ignition switch hot (Excite) which turns the ALT on when the key is turned
Red/Purple is sense (always hot) and tells the ALT when the battery is charged
Orange is Output to the battery

 

[GatCat74]

Do you think the orange, the red and the red/purple can all go on to the charging post together?

 

[alldodge]

Do you think the orange, the red and the red/purple can all go on to the charging post together?

No, The orange is the output line, and if the red/purple and purple are connected together the alternator and the ignition will always be ON. You will not be able to shut the motor OFF, and it can drain the battery if it is shut off another way

 

[Bt Doctur]

your working with 2 different alt.return that new one and get a GM 3 wire or a 1 wire
The one you list is for a serpentine belt install and is a non-adjustable setup,

 

[boatman37]

Sorry. haven't been on since this thread started. mine looks completely different than that one but my orange wire that runs to the starter is cut off for some reason. somebody said maybe because they installed an isolator? either way mine has a larger post and a smaller post and my terminals would only fit one way. i ended up putting my original back on because i had it rebuilt and was still having issues but found out it was just dirty connections so the DB was still good. i would have to look at my alternator again to remember what went where. there was a red wire, purple wire, and i think a third wire.