View Full Version : wiring up the altenator/ammeter/regulator
10-24-2011, 02:44 PM
First off Ive researched for hours and am still very confused. Im in the process of (attempting) rewire my 1970 S800a. Got to the engine harness/altenator/voltage regulator and after comparing the directions that came with the EZ-wiring Kit(12 circuit),shop manual and forums,Im baffeled!:confused:
First off Im not sure if its an altenator or generator,the shop manual keeps referring to a generator?? Not sure if the PO's changed it at any time.
What I did notice while removing the harness ,is the white wire was bare in several spots,looks melted.
I would like to use what I have if possible as opposed to buying a new altenator with an internal regulator.
How should I wire this up? Will it work with the OEM ammeter(if it was designed for a generator)?
I recall reading hooking the altenator with a light in line?
Now I remember why I hate electricity!:censored:
I called EZ-Wire and they have yet to get back to me?
10-24-2011, 03:50 PM
A 1970 would have come with a 10dn alternator. In all honesty now is the time to convert to the internally regulated alternator. The kit likely comes with the plug for that alt as well as directions for wiring it. Nowadays a reman 10si part number 7127-12 will usually run you less than either the 10dn alternator or a quality version of its external regulator and will always be in-stock at any parts store for years to come. If you are really set on keeping the 10dn google 10 dn wiring diagram.
They probably don't have instructions on how to hook up an ammeter so I'll give you the basics. Run a wire from the B+ stud on the alternator to the (-) side of the ammeter, connect the main power supply wires from the kit on that stud too. From the (+) side of the ammeter run a wire to the B+ stud on the starter solenoid or hot side of the Ford starter relay if you've done that upgrade. Again now is a good time to do that. (Prevents cooking that new wire running it down by the exhaust to connect to the starter, among other things). Some sort of circuit protection should be incorporated in that wire running from the ammeter to the starter solenoid/relay. I prefer a manual reset breaker. The ammeter side of what ever you choose for the main protection is where you should connect the alternator's voltage sense wire.
10-24-2011, 08:41 PM
I knew someone would say that! I guess if it makes the wiring easier and makes the scout more reliable ,than Im in. Would there be any further modification required to wire it in? work with the oem ammeter? wireing..? thanks,
10-25-2011, 10:52 AM
The internally regulated alt can be used with the ammeter it was in the SII and later D-series.
The instructions that came with the kit should have a wiring diagram for the GM 10si.
The basics are
Alternator exciter (white) to alt #1 terminal.
Alternator pwr (red) to the B+ stud on alterantor.
Solenoid pwr (red) to the ammeter (-) side
Rest of Solenoid pwr wire or other should run from the ammeter (+) side to one side of the circuit protection device. Either the fuse link supplied or a appropriately sized fuse or manual reset cir breaker.
The circuit protection device connects to the starter solenoid or relay.
#2 terminal on the alt should go to the vehicle side of the main protection device but you can connect it to the B+ stud on the alt as per the directions.
10-25-2011, 09:13 PM
10-27-2011, 08:51 PM
well I went to Auto Zone and picked up a duralast 7210-12 for $49.99 + core, with a lifetime warranty!
now lets see if its an easy hookup?
thanks again Eric:rockon:
11-17-2011, 05:49 PM
OK,update.I havent had much time latly ,between work ,wife and my 3 year old to putz around with the Scout. But I mounted up the altenator and began the wiring. Just to confirm,the manual says I need a ballast resistor and Ive also read I need to wire up an idiot/charging light. Can anyyone confirm this?
11-17-2011, 07:38 PM
You need at least 10 ohms of resistance in the wire going to the alt "turn on" circuit, the #1 terminal on a SI alternator. It doesn't matter how you get that resistance a 194 bulb by itself is what GM used from the factory on many installations, while IH, since they have an ammeter, used a resistor wire.
11-18-2011, 03:32 PM
Ah this must be the infamous blue wire referred to in the shop manual,thats an exact length to provide the correct resistance. Co I can wire up a light ot resistor instead of worring about the length? Will I also need the ballast resistor attacthed to the coil?
11-18-2011, 06:32 PM
The only blue wire is the main power feed as it is 10ga and that is the color code for 10 ga. The original wire would be white with a cloth like covering and yes it is one of the 2 wires noting that the length is important. The other is the resistance feed for the ignition.
For the alternator yes a plain old incandescent light bulb is all you need, the 194 like used in the rest of the dash and marker lights. It will serve as the current limiting device preventing the alternator's regulator from melting down and serve as an indicator too.
If you are running a points ignition then yes you'll need a ballast resistor if you are not reusing the original resistance wire.
11-20-2011, 09:05 PM
thanks for clarifing that.
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