Single wire alternators

you don't, it's internal sensing, doesn't need an external "user" (ie the light)
 
6-71 said:
How do I wire up the ign light on a single wire alternator?:confused:
Click to expand...

ign, on this side of the pond refers to the ignition....specifically start/run side of the spark coil....points OR HEI....

I have to assume you mean the ALT/GEN/BAT RED light on the dash....

it has been marked with one of the above terms over the years....

if so, there is typically no install for that on a ONE wire alt....

the interior wiring is altered on the alt...it is a take off on a 'marine conversion' meaning for higher RPM steady on operation...so it typically will not go discharge until idling in/out of the docks.....a minor point.....what was happening back when these cars were new, was the anti explosion screens...that made them ONE output wire operational....fumes and such for the other regulator leads...sealing the regulator terminals was a issue, I suppose...

I'm just quoting from experience and some marine mechanic friends....

so you can use a one wire in a car...but you get peculiar operation....

discharge at idle is the main one....

you have to run the red light wire to the L point on the alt...since most of the internal regulator alts have replacement rear cases these days, you have no markings on them.....the OEM ones did.....

so to look at the rear of the alt...the MOST CLOCKWISE goes to the dash light bulb....one side the other side of the bulb going to the switched hot...like ignition....

hope this helps.....:flash:
 
Help..

Guys thanks for the info. I'm getting other mixed info on this subject. From what the supplier tells me they will only start charging 'after start up' when they are revved over 3000rpm, but once the alternator kicks into charge mode it then works just like any other..even when idling. Is this right?
:search:
Thanks
 
mrvette said:
Twin_Turbo said:
you don't, it's internal sensing, doesn't need an external "user" (ie the light)
Click to expand...

Marck, beg to differ.....they tend to go to no output at idle....

but that is obviously load and RPM dependent....

:flash:
Click to expand...


What do you mean? A 1 wire alternator is internal sensing, not external. There is no way to wire up the gen light, which on a normal alternator is the load required to excite it. Also, the 1 wire alt won't charge at idle after starting. One blip of the throttle and it will start charging.

How do you propose we wire up a gen ligth w/ a 1 wire system?
 
I bought a 1 wire off of ebay and have been using it for a few years. It works well. There is no need to increase rpms after startup. I think the regulator is optimized for this intended purpose.
 
Twin_Turbo said:
mrvette said:
Twin_Turbo said:
you don't, it's internal sensing, doesn't need an external "user" (ie the light)
Click to expand...

Marck, beg to differ.....they tend to go to no output at idle....

but that is obviously load and RPM dependent....

:flash:
Click to expand...


What do you mean? A 1 wire alternator is internal sensing, not external. There is no way to wire up the gen light, which on a normal alternator is the load required to excute it. Also, the 1 wire alt won't charge at idle after starting. One blip of the throttle and it will start charging.

How do you propose we wire up a gen ligth w/ a 1 wire system?
Click to expand...

On this side of the pond, the SI series alts from GM were widely used on boats and as such were modded with external shells on the backside with metal window screen fine mesh material in back, and same inserted in front inside the front shell....I modded such alt for my Volvo powered boat some 20? years ago when the Volvo alt shit and it was 50 billion bux for it....so my Marina owning old neighbor buddy told me of the GM alt and what to do, so I got the screens from his parts dept....

and one of the mods was to take the output stud directly to the typical RED, or MOST clockwise viewed from rear , regulator pin....and you are correct in that the least clockwise pin was unused.....the rear screen/cover he sold me did not have any holes for any wires to the regulator....

And so I did have to rev the engine to about 3k to get the alt to charge, but idle was like 800+ rpm so no sweat....it always charged....

now on any other vehicle, over the years, the one wire always had a problem dropping out at idle....defined as less than ~800 rpm....like my big Pontiacs, and any milder engine....same behavior the motor home with the CS144 exhibits....at idel under a heavy load, the alt will drop out....it has a idiot light but no ref signal....maybe I need play with it a bit....decrease the load resistor to the 'L' terminal.....

NOW in the last few years a buddy with a 350 chebby in his Chaparral ~22' boat we put a SI alt on it, he bought the alt from a boat source, and so it came with that back cover just like my old one, BUT has the regulator outputs fed through the blow screens and so I hooked it up via same as a car....and it does NOT drop out at idle which for him is less than 700 rpm....

My conclusion is that IF idle speeds under full loads are up around 800 rpm or so, that one wire alt is fine, if under that, and the rpm maybe vary a tad, it will drop out and it's load dependent also...proved that one myself in the vette....:ghost::friends::flash:
 
what you guys are describing is a 3 wire regulator jumpered to sense at the alt. That relies totally on the alternator self exciting which takes some higher rpms and could drop out at idle.

A 1 wire regulator has some more sophisticated sensing circuits to detect a voltage drop (voltage delta) which means the engine is starting. That acts as a switch to turn the field on instead of the ignition switch. It needs to see some ripple from the alt to maintain. Once the ripple goes away it assumes 0 rpm and shuts the field off.
 
rodeck350 said:
what you guys are describing is a 3 wire regulator jumpered to sense at the alt. That relies totally on the alternator self exciting which takes some higher rpms and could drop out at idle.

A 1 wire regulator has some more sophisticated sensing circuits to detect a voltage drop (voltage delta) which means the engine is starting. That acts as a switch to turn the field on instead of the ignition switch. It needs to see some ripple from the alt to maintain. Once the ripple goes away it assumes 0 rpm and shuts the field off.
Click to expand...

Wasn't until just recently I saw a schematic of that internal/white regulator on the SI series....I am told there are different types depending on what alt output was supposed to be....and your post makes sense to me....

the light bulb, or resistor wire like in a old shark is necessary to keep it on charge with ~600 rpm idle....otherwise they seem to drop out....

:quote:
 
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