Performance Boats Forum banner

1 - 20 of 48 Posts

·
Registered
Joined
·
65 Posts
Discussion Starter #1
Can someone please draw me up a wiring diagram for a 1 wire alternator setup. Looking at how mine is wired and it just doesn't make sense. It's for an Olds 455 Thanks
 

·
mo balls than $cents$
Joined
·
11,734 Posts
+ on the battery ---------------------to the terminal on the back of the alt. easy peasy, 1 wire;)
 

·
I'm baaaaack...
Joined
·
4,365 Posts
What he said
 

·
Registered
Joined
·
65 Posts
Discussion Starter #4
Thanks - that's what I thought - I wonder where the 2 wires hooked up to it go LOL logs coming off tomorrow and OT's going on so the semi-wad of wiring will be easy to get to and redo. Thanks
 

·
Registered
Joined
·
65 Posts
Discussion Starter #5 (Edited)
OK here's what I think I have determined from this mess. Well, I guess it isn't a "real" bad mess - hard part is I am sure I'm working with the 1975 wiring and some of it is faded enough that it's hard to tell blue from black, yellow from white, etc.
ANYWAYS - the diagram that came with my new alternator shows the wire already discussed (post to pos. terminal) Then there are 2 side terminal wires and directions state:
Terminal 1 must receive voltage. This voltage is provided by the indicator lamp on most "vehicles". However vehicles that have gauges will use a resistor in place of the indicator lamp. (there is an exsisting wire that runs from the amp gauge in the dash to very close to alternator so I am persuming that is wire #1
Terminal 2 must have battery voltage. This voltage is supplied directly from the battery and will be present whether ignition switch is in the "ON" or "OFF" position. (there is a wire that runs from the post on back of ignition switch labeled "Batt" and it runs fairly close to alternator also.
I'm thinking and hoping that these are the correct 2 wires. There is a heavy wire (10 guage) that was one of the wires hooked to the old dinasaur alternator that lookes like it came off one off the starter posts. (hard to see - still have logs on - don't want to pull them yet in case UPS doesn't show tomorrow on there scheduled delivery day - party time weekend!!)
Well if this sounds right or wrong I am sure someone is a wiring wiz on the boards and I hope they can point me in right direction.
 

·
Premium Member
Joined
·
984 Posts
You are making this more difficult than it needs to be.

1.)Disconnect battery

2.)Remove old alternator and install new one.

3.)Connect output wire(the larger of the three) to the output post of new alternator.

4.)Remove the other two wires. They are no longer used. This is real simple if you have a terminal block on the engine. If no terminal block, insulate the wire ends and fold wires back into harness(unless you WANT to follow them all the way back to source).

5.) Reconnect battery

Since you have an amp gauge, the output of the alt goes all the way to the gauge and then back to the engine and then back to the battery. With a voltmeter, it would not run to dash but would take a more direct path to battery.
 

·
Registered
Joined
·
65 Posts
Discussion Starter #7
So you're saying that signal will already be route to guage then and just ignore these other to post? hmmm Let me finish what directions said about each terminal if it isn't hooked up (did a little abbreviating on last post):

For terminal #1: "Failure to have voltage at terminal #1 may cuase:
No charge, Indicator lamp off.
Charges OK, but indicator lamp is on.
Will not charge unless engine is "revved" up. Indicator lamp may come on when unit begins charging.

For terminal #2: Failure to have voltage at this terminal will cause:
No charge, Indicator lamp off.

Sorry if I sound a bit nervous - had battery die on the lake the other day and took 1 1/2 hours to get a jump. Hopefully I am overkilling here - just want to do it right the 1st time :)
 

·
Premium Member
Joined
·
984 Posts
Are those directions from the NEW alternator? Is it truly a one-wire unit? What brand and model?

And how about some pics of the old and new units.
 

·
Registered
Joined
·
65 Posts
Discussion Starter #9
The new one is a Delco Remy #20038 The old one is an old Motorola Transpro 5-197 Give me a sec and i'll snap a couple quick pics (have to figure out new digital camera - the little woman dropped my old one a couple weeks ago and it is now taking pictures of the bottom of Palasades Resevior.
 

·
Registered
Joined
·
65 Posts
Discussion Starter #11
1st 2 are the old Motorola
Motorola 1.jpg
Motorola 2.jpg

this is the only decent one of the Delco - hard to get mounted in boat but tried to show the other plug I have been referring too.
Delco 3.jpg

Hope these work 1st time posting pics here...
 

·
1 boat's never enough
Joined
·
107 Posts
Hook it up the way old squirt described and you'll be fine. Terminal 1 is for an idiot light to tell you when it's not charging (you have a guage for that). Terminal 2 is used for sampling voltage at a terminal strip on a car so that the alternator will charge the battery and make sure you maintain about 14V at the terminal. For a boat you don't need to worry about this because of the short distances and lack of nav systems, dvd, head lights etc . . . Just hook it up and put a voltage meter across your battery terminals when it's running. Verify >14V and you're good to go. Good luck!
 

·
What the Hell is That?
Joined
·
1,633 Posts

·
Horsepower sells Engines
Joined
·
402 Posts
OK three termainal you said it was a one wire, some alts are both if you look down the side of the two terms. you will probably see a wire between the two, post discription the big one on the back is out put from the windings "charge wire"
one of the other is power coming from the diode trio this goes to the "light" one side of the lite is powered the other goes to alt, light gets ground through alt till it starts charging, the last is the input for the voltage regulator input of there is no jumper in there your not going to charge input is either on key switch of jumped to the out put of the diode trio. if you need a pic wright back ill send one from a text i have. good luck.
the other question i have is you say exaust logs your pic has pipes
if you replacing that explosion prof alt with that standard auto, you could be asking for trouble in an inclosed engine compartment BE CAREFULL
 

·
E-7 Sheepdog (ret)
Joined
·
6,834 Posts
+ on the battery ---------------------to the terminal on the back of the alt. easy peasy, 1 wire;)
I'm bad at drawing pictures on the computer, but, that's what it'd look like. :D

One wire, from the post on the alternator to the "+" post on the battery, 8-gauge wire.
 

·
E-7 Sheepdog (ret)
Joined
·
6,834 Posts
should have ground post/terminal some where
Nope. Alternators ground through the housing, which is bolted to the engine block. I've never seen one with a "ground wire", ever.

The alt. output wire CAN go to a starter solenoid post, as long as that post is the "battery hot" post, not the post to the starter. Either way, the Bat. cable at the starter, or the battery "+" post, that is "connected to the battery"
 

·
Registered
Joined
·
582 Posts
one wire

My delco one wire works just fine with only the #8 pos wire hooked to the main terminal. I believe that the delco units are made from GM cores and they retain the spade terminals for "idiot light" use only. The reason they are "one wire" because they have a self exciting regulator, unlike the motorola you took off which takes a signal wire to "excite" (activate) the regulator (the square thing on the back of the alt).
 
1 - 20 of 48 Posts
Top