orion4096

iTrader: (5)

I have a 02 camaro ecu in a ls6 swap car and needed to get the late model cts-v accessories to improve fitment. From reading around it looks like the alternator (2-pin plug and B+) wants L and F both coming from a newer ecu which I don't have. I also read that the alternator outputs 13.8V if there is a failure on the 'F'ield pin so I just connected the battery and started it up and it looks to be charging and holds a 13.3-13.5V charge while driving around as measured by my dash. It's a track car so all the battery needs to do is start the car before each session and last. My only concern is that I'm missing something and the alternator will stop charging.

Does it make sense that leaving both pins floating will make this alternator charge?

Should I hook up a 12V signal to the L pin? I couldn't find any documentation for what signal the two pins are expecting.

I found some (attached) pics on a similar alternator, but they didn't answer my questions.

orion4096

iTrader: (5)

Anyone know more about this alternator?

monzaaddict

Take a look at the wiring diagram that corresponds to your ecm (year and operating system).

The 1st attachment below is is for a 2003 dbw corvette application. On the C2 connector pin 15 goes to the alternator terminal L and pin 52 goes to the alternator terminal F.

2nd attachment shows the 2002 f body pinouts it shows pin 15 to terminal L. Pin 52 is unused but I would guess it has to do with the different alternator used on the camaro or more likely the way that a generator fault is indicated. The F body application might have used an idiot light in the dash to indicate a generator fault whereas other cars use the ecm to detect the fault which is which is sent via a class ii serial bus to the instrument cluster illuminating the malfunction indicator lamp and logging corresponding code. I would bet that pin 52 could be hooked to alternator terminal F.

I believe pin 15 should have constant about 5v with the ignition on. Test the pin when doing your installation just to verify. This is the generator turn on signal. Some alternators will be damaged if 12v is sent to terminal L (GTO alternator). The fix for them is to add a resistor to bring the voltage down to 9v. or use idiot light circuit. If resistor or idiot light burn out alternator may be damaged. The voltage differential that the regulator sees is needed to induce current flow and turn on the regulator. The third attachment below indicates that alternator pin F is grounded by the alternators internal regulator sending a fault signal to the ecm in turn illuminating the MIL lamp and generating a fault code.

monzaaddict

more info

http://www.stevesnovasite.com/forums...=179119&page=3

http://www.familycar.com/Classroom/charging.htm

https://ls1tech.com/forums/conversio...lternator.html

http://forums.bimmerforums.com/forum....php?t=1375257

https://ls1tech.com/forums/conversio...ing-light.html

http://944hybrids.forumotion.com/t12...g-gto-specific

http://forum.miata.net/vb/showthread.php?t=409293

copied from above link

A little background. LS1 F-body and Vette use only one wire on the alternator plug, truck harnesses use two wires. These wires feed/recieve info to/from PCM.

They provide electrical load info and monitor/adjust the alternator output to maintain sufficient voltage to charge the battery and operate the vehicle electrical load on newer LS1 harnesses. On any GM application, the alternator plug must have a lower voltage than the battery at the alternator plug to charge propperly. Thus the need for a lammp or resistor to drop some voltage. This has not changed since alternators were first used on GM vehicles in the early 1960's. On older GM vehicles that did not have the PCM adjusting the alternator output, when you turn on the key the alternator light illuninates because battery voltage is applied to one side of the lamp and the alternator plug has no voltage (alternator not spinning, no regulator control, and engine not running). Once started and alternator spins the alternator outout increases till the voltage is the same on both sides of the lamp, thus turning it off because there is no current flow. If the regulator or laternator goes bad the voltages differ enought to turn on the lamp. The lamp resistance changes with current flow providing excellent feedback but a resistor value stays the same. Bottom line is the resistor does the same thing just without a visual indication. Resitors do not provide this indication. If the resistor burns up, quite possible as some people do not install adequate wattage resistors in series with the alternator, the alternator tries to provide more power and will burn up.

Also, within the PCM file the injector pulsewidth calculation varies based upon battery voltage so it is important to have the best/stable voltage regulation.

So you need to have either a resistor or a lamp.

http://www.justanswer.com/chevy/122y...e-10-feet.html
__________________

orion4096

iTrader: (5)

Thanks for the links. This helps. I need to figure out which wire is L and which is F on this alternator. I assume A is field an B is turn-on in my first pic. Then I can hook up the L wire to my 12V+resistor wiring that I had running to the f-body alternator. This didn't work on the cts alternator when I tried it the first time because the field wire was floating and doesn't internally hook up to the output like the f-body alternator. The simple solution would be to wire a fusible wire from field to the battery out post on the alternator.

S10xGN

iTrader: (11)

All the GM alternators I've seen have the terminals marked (cast?) into the plastic surround where the connector shell plugs in.

orion4096

iTrader: (5)

I hooked up pin A to the battery terminal and B to the ignition wire with a resistor in series (which turned on the f-body alt without any issue) and the alternator does the same thing it did with the pins floating: charges at about 13.8V even at higher revs. Maybe that's what it should do with the field wire on the battery post. I guess I'll leave it unconnected for now. I was hoping to get it to charge at over 14V since the battery is a 4s4p A123 LiFePo.

Deserttaco

iTrader: (1)

I'm going out on a limb and going to say that the CTS-V alternator is very similar to the 05-06 GTO alternator. I don't believe that you can properly run this alternator with the F-body PCM. It does not have the proper circuitry for the "Generator Turn on Signal", and the "Generator Field Duty Cycle Signal"

Here is the wiring diagram for the 05-06 GTO Alternator
http://www.ls1gto.com/forums/showpos...8&postcount=15

What about using an F-body alternator and machining the mounting bracket .75" so that it'd be at the same depth as the other accessories?

monzaaddict

I think you got it backwards

Are you using the 12200411 ecm?
Alternator terminal L (cavity A) gets the resistor or goes to pin 15 on C2 connector without the resistor. This should be connected to a switched source (on during start and run). I think you can leave off the resistor - as far as I can tell it is the gto alternator that must have the resistor.

Alternator terminal F (cavity B) can be left open or connected to pin 52 on C2 connector.
This is not needed. Alternator grounds this terminal when there is a fault logging a diagnostic code in ecm and possible illuminating mil light.

I believe the way you hooked up your alternator with terminal F to 12v bypasses the regulator. This is why your alternator is putting out a constant 13.8v.

this mentions bypassing regulator
http://www.bronek.org/sailing/zamind...leshooting.pdf

this mentions use of idiot light
http://www.vw-resource.com/alternator_wiring.html

I would just hook the wires to the ecm

The gto alternator is mitsubishi and a cts-v alternator is nippondenso
The picture below is of a gto alternator and a camaro/truck alternator
below is the cts-v alternator which appears to be similar to camaro/truck alternator.

monzaaddict

more info on the turn on circuit ( this is not specific to the cts-v alternator but the idea is the same)
Wiring these alternators is quite simple. All the Si alternators can be considered both 2 and 3 wire systems. To activate these alternators you are only required to supply the main battery wire to the (BAT) terminal which must have power on and an ignition wire to the #1 terminal. Most all the Si series alternators should have two spade terminals, but some that have three terminals, the third is for a tachometer connection and senses the alternator RPM.

Near the spade terminals, the rear housing should be marked #1 and #2. Some aftermarket housings are not marked and others may be worn off. So if your alternator housing is unmarked, look from the rear of the alternator: the #1 terminal is on the left and the #2 on the right. You only need an ignition wire to the #1 terminal to make an Si series alternator work.

The ignition wire to the #1 terminal can be supplied in two ways, either a direct ignition wire from the key switch or through a light bulb. Running the ignition wire through a light bulb before connection to the alternator will give you a warning if your alternator fails to start charging or if it quits working while the engine is running, this is commonly known as the idiot light. Another thing that should be mentioned is the #1 terminal must be ignition switched. I have heard of situations where a wire was run to the #1 terminal that had power on at all times. What happens is when the engine is turned off the #1 terminal switches to ground which over time can burn up the voltage regulator or the wire if power is not cut to the #1 terminal.

orion4096

iTrader: (5)

The alternator is a Denso identical to the one in your right picture. No markings anywhere I could find for pin 1 or 2. Only for B+. The connector I bought had pin 1 and pin 2 markings and match what you said about the orientation relative to looking at the alternator from the back. I hooked up switched 12V to pin 1 and it still outputs 13.8V. I revved it and no change in V.

monzaaddict

On the back of my alternator on the plastic where the connector attaches the terminal furthest from the large lug is labeled L. The terminal closest to the lug is labeled F

sounds like your alternator is working as it should to me. If it were me I would be worried about running 12v to the alternator just in case it is not designed for this. The alternator is not cheap to repair or replace. I would run the wire to the ecm.

If you have the 12200411 ecm and are using a 2001 -2002 camaro operating system - cable operated throttle body, you could run a wire from the C2 (red) connector on the ecm from pin 15 to the L terminal of the alternator and you should be good to go. If you need wire and terminals go to http://www.eficonnection.com
you need delphi micro pack 100w terminals ( verify wire gauge - call the owner mike he will help)

monzaaddict

Just looking at this again. I just noticed you were originally asking about a 09-11 cts-v alternator. I think you need to install the voltage regulator from an earlier cts-v alternator.

orion4096

iTrader: (5)

Old thread, but the easiest solution was to use a 04-07 cts-v alternator. It mounts up in the y-body position with the LSA alternator bracket that I already had. It also takes the f-body 4-pin connector of which only the two center connections have pins (L and F) and only the L-pin is needed to hook up with a lamp/resistor and diode. Part number: 25766345. New one from amazon with original, quality parts was significantly cheaper than a crappy reman/rebuilt one from the local auto stores.

I also tried machining a f-body alternator bracket down 3/4", but the f-body alternator bearings only lasted about 10 minutes on the track before they were squealing and the pulley wobbled. Looks like the bracket isn't square. Other people seem to have this working so must be a problem with my bracket.

EDIT: Probably could have used an older regulator in the 09+ alternator as suggested, too.

mrvedit

The CTS-V alternator (DR44 and DR44G) from 04-07 appears to come in both 2-pin and 4-pin varieties.
Deserttaco was correct - they will function as a 1-wire alternator putting out 13.8 volts UNLESS you have a compatible PCM hooked up to them. An old-style resister/light will NOT work. These alternators require a PWM (Pulse width modulation) signal from the PCM to control the output voltage. The signal is a square wave with between a 5% and 90% duty cycle. If it is 0% (disconnected) or 100% (hooked up to resistor) the alternator defaults to its 13.8 volts.

I learned this the hard way - I bought two to use with my 2002 PCM and was frustrated that they never put out more than 13.8 volts. I finally learned all this on another site(sorry forgot the link) and ordered an ACDelco AD244 alternator which works perfectly with my 2002 PCM, or would only need a resistor or light connected to it.

orion4096

iTrader: (5)

The 04-07 CTS-V part number I listed is for a AD244 with the older style internal regulator/circuit.

It isn't that hard to build a 5V 128 Hz PWM signal and dial in the duty cycle to the desired voltage, but seeing as it's for a track car I wanted to keep it simple.

mrvedit

There are just a stunning number of different alternators out there now with different electrical needs. Not like the old SBC days.

I also thought of generating the square wave with an analog or digital chip but there are only 24 hours in a day.

orion4096

iTrader: (5)

Stuck at home sick today so I stopped by Fry's before picking up some medicine and made this for $12. Not sure if it works on the car, but it looks good so far.

mrvedit

Nice. Too bad I just sold my second DR44 on ebay or I would test it.
Just use a 555 timer?
Sorry, total hijack. Do you like that scope? Looks like a good value for $350. Love that it even calculates/displays the duty cycle.
And sorry you are sick; this winter just doesn't want to end.

orion4096

iTrader: (5)

I used a cmos 555 with a simple RC circuit. Simpler than this, but this explains how it works: http://www.dprg.org/tutorials/2005-11a/. Here's the one I built: http://clarkson-uk.com/555-timer/ope.../hiframes.html. It has some limitations, but the output is what I wanted. I probably should add a diode before hooking it up. 10+ years of writing software and this stuff is all magic again.

The Rigol scope has been good to me for the past 2 years with light use. My friend also has the same scope and his screen died, but they warrantied it. Great picture, easy to use, decent bandwidth, and 2 inputs on a digital scope for $350. I'm happy with it. The software that comes with it is pretty awful so I usually end up taking a picture of the scope rather than importing the saved waveform. The "automotive" scopes were outside of my budget and didn't seem worth the extra cost for what I do with it.