forbiddenera

Okay..background..I have a Canadian Civic - no LED in the fuse box, ecu doesn't look for it etc.

It came with a b18b1 from a 99, the sensors and injectors were all obd1 as well as the ecu (was actually running off a p06 if you can believe it..like a non-chipped p06 for a d15b7..)..now..the alternator, I assume, was the original for the engine..and had a 4-pin plug..the plug was not spliced on, the harness wasn't spliced at all actually.

I suppose if Canadian Tegs did have the ELD then it makes sense that I would have a Teg obd1 engine side harness, with the 4th wire running to the shock tower and going nowhere I'm sure.

Now, when I did my swap (b17a1) I had a few different alternators around and extra plugs, so I wired in the two extra plugs..I don't recall the exact colors but put similar/same together...I went for the cleanest looking alternator in my pipe which had a round 3pin plug I believe.

The alternator seems good, it is putting out a surprising amount of amperage..except it's stuck at 12.7v. Now, I could see a 4-wire alt without an eld wire doing that.. but what about a 3-wire that should (but may not) have the right wires? If I missed the ignition signal wire or fr, would this be the result?

I can dig out my service manuals and figure out the exact wiring if necessary but I want to be sure I indeed f*cked up the 3 wires and that it's not the vreg or something. I assume either is possible but wanted to check, unfortunately most of what I've searched points to the ELD crap I ddon't have, nor would want (lots of aftermarket electronics not run thru the stock fuse box.....).

forbiddenera

I'm also confused about whether the ALTC (alt control) is strictly ELD related or used on all cars.

I guess ignition should turn on the vreg, which should be right if I'm getting any voltage?
Warning goes to light, which, I don't actually recall it coming on when my belt slipped off (which it should have, no?)
and third is ALT-FR? Is this just ALTC from ecu?

maybe I have warn/fr mixed...wierd tho I think the wire colors pretty much lined up..will have to check my harness again but some clarification from someone more experienced with this particular matter would be great

forbiddenera

I was able to run some bass, headlights and inverter for my laptop with only dropping to like 12v at the most, barely dipped with some RPM going to it..so it's putting out good amps but the voltage is low, which is why I'm wondering if it's not getting the signal it needs to go to 14v? But I'm not sure the non eld/3 wire ones even control like that, or do they thru ALT-FR? if its the vreg I'd almost swap it for how good it's performing otherwise

forbiddenera

A few hours later...

ELD,Alternator & Fuel Cut,A/C,Idle Tweaks - Team Integra Forums - Team Integra
• View topic - Cutting the ALTC wire
but the best
https://www.autoserviceworld.com/car...rging-systems/

so even without the ELD the ecu has the ability to tell the alt not to charge - it is def charging a bit in my situation, my battery would die real quick if it wasn't (and did when my belt slipped off) .. Or is by definition "Not charging" just dropping the voltage to what the battery would normally sit AT, e.g. 12.7ish volts?

will double check my wiring now that I have clarity on what to look for, if the wiring checks out then it must be the vreg I guess...?

the alternator looked nearly new, dunno where it came from, came with one of my b17s.. just seems odd that the output would be exactly that voltage ..

forbiddenera

Actually re-reading the last article, seems that it should only control voltage with altc, which this alt shouldn't have.. it's late, easy to run your brain in circles.

so there's again..on this 3 wire alt..
1 wire for warning light
1 wire for ign to turn on vreg?
1 wire for altfr which supposedly outputs to ecu

Now the confusing part, is even in the honda factory manual, it says that the ecu controls the alternator output - in the same page it shows that the ELD is part of US only cars but says every car does control alternator (at least referencing the 95 civic manual)

that manual also shows a 4 wire plug tho..so does my 93 Integra manual..

Now..canadian cars don't have eld, but do all the newer cars have ALTC?

Is the only point of the FR on a car with a 3 wire alt to adjust idle?

The ignition power for the vreg doesn't route thru ecu at all?

I wish I could xray vision my engine harness from here to confirm I did indeed wire it right, because then it has to be the vreg .. but I want to think I didn't (so I don't have to take the damn thing out haha)

forbiddenera

Another article..

https://www.google.ca/url?sa=t&sourc...3SzQ_Q5wbSQ1Qq

makes me question..i had a 4 wire before and it worked (didn't put out too good of amps tho) so the ALTC must be there and booked to ECU? I never tested before, I suppose I could open one of my old tunes and verify that alternator control is turned on...

forbiddenera

Now I'm even more confused..where the heck did the 3 wire alt come from ??

I thought maybe a EF/ED..? The guy who sold me the one b17, think he had it in a rex. Just checked the CRX manual it shows 4 wire..

Also checked the da manual and it shows 4 wire..?

forbiddenera

Well..while the crx manual shows a 4 pin plug, the wiring diagram shows 3 wire.

forbiddenera

But now that I've seen the differences, I guess it comes down to simply..if the ign wire is getting power, it should charge proper..if not, it should probably not output anything..?

Only thing I can think besides a bad vreg is maybe I mixed up the warning light and ign wires, warning light does have ign on it but I could see it maybe acting weird.

Will double check the wiring tmr, if good, either swap alt or vreg.

curious what I'll have to take out to get my alternator out..never swapped an alternator without the engine being out of the car.. haha.. the teg manual shows axle removal. Crx shows just pop out, lol.

the alt that's in there must be from some sort of ef/ed or something, the only way I could make it fit was with this random bracket that now that I see the service manual is obviously from one..

bleh..so then the only question I have left is if the (newer than ef) Canadian cars indeed do have altc wired already, what I gleam from the fsm is yes even with no eld..

even with my old motor and 4 wire alt, I never noticed it go under full voltage..then again maybe my ecu was forcing altc high always. I actually haven't noticed it go low in any datalogs but not something I was looking for either.

forbiddenera

I wonder if maybe I have it backwards and now it's a 4 wire and before it was 3..that would definitely explain the output I'm getting but I'm not sure that's right..all I've done is read all night and confuse myself..sadly I could probably answer it quickly looking at the harness and checking on the car but .. Maybe I should sleep now.. 7.50am..crap!

would be happy if that were the case. I really dunno now though. I do know a heck of a lot more about how the honda charging system works tho. Still want verification that altfr only controls idle on non eld cars.

mk378

The light should come on with the key on and alternator not turning. If it doesn't, something rather fundamental is wrong. The ECU doesn't have control of that. The "I" wire should be live all the time the key is on. The "L" wire will be pulled to ground when a fault is detected to turn the light on.

I have not studied this system in much detail but my understanding is that the ELD and FD (Field Drive) wires are inputs to the ECU so it can estimate the load on the system and thus how much torque the alternator will require. This is used to pre-emptively increase the idle air and timing to keep rpm up in case a heavy load is suddenly applied.

The control wire drops the regulator output from normal to about 12.5. Strictly guessing, I'm guessing this is tied in with the logic that drops the A/C clutch when rpm goes very low as a last-ditch measure to prevent stalling out. It probably never acts at any other time.

forbiddenera

Altho wait if it was a 4 wire and the ALTC is d/c shouldn't it go to full volts..? I don't think it's a 4 now..and from what I can tell a 3 should always full volts?

still odd how it seems to have lots of ampacity at such low voltage. My old alt would dim a lot more at idle with a higher voltage..?

forbiddenera

trying to diagnose from memory when you need sleep isn't the best start but it has been something I've been thinking about lately & needing to solve, ideally I'd like to use the alt if it's good as it's relative output at idle, voltage aside, is higher than the old one. I do have others including the old one but the bin they're in didn't get covered and They re in snow and ice. I picked the cleanest best looking of the bunch.

Also, I learned tonight that there are different times it will drop to 12.5v, I believe one of the links I posted describes them - but it's not just in the circumstance you state.

It seems also from my research that some (even obd2? Or maybe only obd2?) Canadian Tegs have a 3 wire plug.

I do believe I had this reference ( OBD0/1/2 Alternator Plug Wiring ? .:FFS TechNet:. ) when I did the wiring so, not sure how I could have got it wrong but I will have to verify the exact details by looking at the harness, it was over a month ago I built it, maybe almost 2.

tony_2018

Bro...if your ride is obd1, stick to obd1 alternators, which means you'll need an obd1 b-series alternator.

forbiddenera

"bro"..no offense but..this isn't useful information at all nor really good advice... I swear I've seen more intelligent responses from you so I'm a bit surprised..? Not trying to be a dick, I can see it coming off that way..but..no dick-ish intended... But, this is a technical forum..and at the alternator itself, the only difference between obd1 and obd2 is the plug - and this isn't a difference I was concerned with, the difference I was concerned with pertains to certain Canadian models only having a 3-wire.

I'd be happy for you to prove me wrong but it doesn't SEEM like your advice is firmly grounded in technical logic - perhaps "technical support" logic (tell the user their configuration isn't supported, because it isn't stock and imply it's the cause) .. I've even linked to a page showing the necessary wiring for each plug type, there's tons of adapter harnesses and my OBD1 car ran fine with a OBD2 alternator (at 14.6v for over 10 years, along with a stock d series ecu, but that was the 2nd previous owners doing and the 1st previous ownermdrove that way for 10 years) 'bro'..

I get telling someone with a stock Civic to get a OBD1 alternator if they have an OBD1 Civic of course but..the whole reason for that is so the plugs lime up. My engine harness has 3 different alternator plugs on it so I can run any type as needed. I was mostly curious as to what the symptoms would be (no charge, low charge) if I did indeed accidentally mix up wires..unlikely but possible.

And really I'm not sure that's great advice for anyone with a swap anyway..what if I had an obd2 engine side but obd1 everything else? I'd need an ob2 alt or to change/add plugs to harness?

again not trying to be a dick.. this is a technical forum and we should be relying on facts, diagnosis and information. From all my research and knowledge on these cars (including spending this last whole night on the topic) I can't see ANY reason for you to recommend that other than it's convenient the plugs are the same..? Now, it does seem like there is the possibility of Canadian cars with 4-pin alternator and ALTC but still NO ELD, at least according to the service manual (shows the ALTC function for all cars and explicitly says the LED is still is a only). Although I haven't found one yet that shows any 3 wire plugs..nor do I know if this information gleaned from the manual is correct. Also, from the CRX manual I read (obd0?) It showed a 4 pin plug still but the diagram shows 3 pins, altc being superfluous but still compatible

Don't want anyone thinking obd level affects anything but plugs and ALTC existing..? Perhaps there are minor mounting differences I'm unaware of but all my units seem pretty similar and bolt up fine..

please though..if you have a good technical reason for this answer, share the details also we can all learn..but if it's just trying to simplify (which I can appreciate but doesn't apply here) then..good advice for stockers (stalkers ? Lol) perhaps but I'm by not stock..lol..

Also if you read, I'm pretty suresrkckpèęì I mentioned (though not 100% sure at this point) that I went from OBD1 car/ecu with an OBD2 engine/alternator to a OBD1 everything..

forbiddenera

So apparently I remembered backwards (I remember saying diagnosing from memory is the suck)

Looked at the car, dug out two of my spares.. all obd2 at this point. My other ones must be in the snow bin

the original engine bay plug is actually obd1 3 pin.

the new alt is 4 pin.

Now I want to say, that's it! No alt control equals no high voltage..but don't people cut the ALTC wire for full time high? Now..if I messed up one of the wires maybe it could be pulling the alt to low..? Gotta unwrap to trace.

I suppose I could swap alts, almost looks like I can pull it straight out in my car but not sure..if I can't I don't want to remove brake cyl, would rather axle but both a bitch

forbiddenera

Of course, the 4 wire obd2 plug has only 3 wires. Which means the ALTC should be clipped (if alt even supports it) which means it should be charging fully..?

I quickly looked and it may be right..might just have to swap the alternator here..have to do a few quick tests. One of my extras does have a test sticker on it from 2013 so..maybe should have used that one instead.BUUT THIS one had the cleanest coils and looked the best.. so maybe I'll swap regulators too..shrug

,looks like I have at least 2 denso and 1 mitsu?

forbiddenera

Ok looking at the ff squad chart

OBD1— OBD2 plug
blue (ALT-FR) tonwhite/red
black/yellow (IGN) to black/yellow
white/blue (WARN) to white/blue
white/yellow (ALTC) towhite/green

edit..wow so much for the nicely formatted table that i pasted.

I AM now starting to think that my 4 pin obd2 plug maybe wasn't originally Canadian or 3 wires - I don't have a white red! I have black/yellow, white blue and white green. Now, does anyone have the actual pin out of the alternator / connector? I suppose I can find a pic of plug with stock wire colors and compare to mine..

Lol..really don't wanna have to swap the alternator or do it and find it was a wiring issue.

forbiddenera

Ok checked a pic of the plug. Looks like I am missing white / red..which means one of the other wires is wrong too..

ign is correct (same color, lol)
I think warn might be right too..but if that is the case.and I'm thinking right..i have my ALT-FR hooked to the alternators ALTC...WHICH could potentially explain it pulling the voltage output of the alternator down!

"This is the one circuit where the computer turns the alternator on and off. The voltage regulator supplies an 8.5 volt (approximate) reference signal to the computer. When the computer grounds this signal, the alternator will stop charging, as in the case of the battery being fully charged and vehicle load demand is low. If this wire is shorted to ground, the alternator will not charge."

and

The second of the inputs is the FR signal (blue or yellow wire, depending on the vehicle), which is the charging rate signal.

"This signal communicates to the computer on how hard the alternator is working to meet the total electrical needs of the vehicle, including the state of charge of the battery and any loads not directly monitored by the ELD sensor. This signal is a digital signal that varies in pulse width according to the total load on the alternator. The computer supplies approximately a 5 volt reference signal through the FR circuit to the voltage regulator."

so, if ALT-FR is switched with ALTC, the alternator will be seeing 5v..? Though above says pulling down stops charging which is kinda opposite of what is expect but, even as someone with tons of years in electrical engineering, I still see stuff in cars that hardly makes sense (weird ground loops and stuff)..

I thought, personally, and this was just a edumacated guess that ALTC was a 0-5 or MAYBE 0-12v output, high being charge low being off - my datalogs show the ALTC output as "1" or ON when it is supposed to charge

So..now I need to either repin my connector or find a new one..at least I'm quite confident I have an incorrect wire.

I think I got it! Will test and report..I hope all my research helps anyone else experiencing issues in the future.

forbiddenera

So where the hell did I get not one, not two, but three 4-pin square plug obd2 alternators?? I originally thought they were from like a DA of EF because they came with the first B17 I bought a bit ago and that guy was working on those cars nothing newer except a Mazda apparently, somehow ended up with a Mazda fuel injector harness..lol.

so I learned and apparently they're obd2.. I went to the junk yard and all the obd2 Tegs and eks had 3 pin plugs.

Wierder is I haven't actually seen an eg with 4 wires there either - the service manual for both USA and Canada shows clearly Canada doesn't have ELD but definitely implies ALTC. The connector is the same on obd1.

I was starting to get frustrated..like..do I have 3 USA alternators? Why, how? Is it possible the JDM ones have 4pin? I know JDM doesn't have ELD.

I was starting to wonder WTF to even get the plug I needed..found one on a integra DC5 (RSX here).. same plug but diff alt obv (k series)..

I'm curious which model that rsx is now too..engines aren't too much in the jy..not usually easy to find the good ones but could be a cheap k swap..lol..

so I now have a 4 pin plug. I can use ALTC if I wanted and may actually wire that up now. Still have to test if it works.

at least I only added the 4pin obd2. I have two obd1 connectors (added a spare when my harness was out because I was considering making a bracket and running a second alt, because i have like 5 or 7, cheap power, this was before I knew what any of the wires did too.. in retrospect if I did ever add a second, I'd just feed it ign)

so I'm still wondering if there's a Canadian cad with the 4pin .. is this maybe an obd2a obd2b thing?

Feriohhh

I don't have much to add, but I commend you for updating this thread. It'll likely be a good source of information in the future.

forbiddenera

Thanks.

So, I am 99% sure the obd1 plug on my harness is actually 4 pin. Not sure if that traces back to the ecu yet.

I did wire in the obd2 4 pin properly and cut off the obd1 3pin and obd2 3pin that was incorrectly pinned.

I then started it, still only 12.6v. I didn't have my laptop connected to see the ECUs status of ALTC, nor do I know yet if it's even connected to ecu.

My next step was to clip the ALTC wire, and then maybe clip everything but ignition, for testing. Went to do this but needed gas, car wouldn't start. Got a Jerry of 94, gonna go dump it in now. If I still only get 12.6v, I suppose the voltage regulator is done and I may even swap one from another alt as this one is the cleanest with the cleanest coils.

I have 2 other obd2 alternators, one of each kind denso/mitsu. If the above doesn't work, my next step will be to swap in one of those.

I checked and I do get ign at the ign wire, haven't verified the rest, I mean that should be obvious or it wouldn't charge at all.

After all this, I may be willing to do a write-up with what I've learned- I've had to sift thru some **** and inconsistencies...I keep reading it repeated over and over that Canadian cars do not have ALTC, I know the EK and obd2 Integra (at least the few I checked at the junk yard the other day) have a 3 pin plug. The service manual clearly shows that there is ALTC in both Canadian and U.S., and that there is no ELD. It is an established fact that the ELD does not come on Canadian cars.

MANY threads I read incorrectly assume/state that the ELD and ALTC function are directly coupled. This is not the case, and the service manual backs this up as well. The ALTC control routine uses data from a bunch of sensors (including the ELD if available) to make it's decision but is completely separate. Otherwise, the ELD controls idle.

I am not 100% sure my engine side harness is the one that came with the car but it's likely. I can verify on my sedan whether that has a 4pin round obd1 or not. The connectors I added were both 3 pin, one round obd1 and one rounded square obd2. The obd1 is actually a 3 pin connector, the other one was de-pinned it seems and was done incorrectly so I won't rely on that for any stock information.

forbiddenera

Okay. Clipped everything but ign. Charges but only 12.75-12.8v measured at battery (12.6v measure at gauge so same as before)

so, regardless of any wiring issue this alternator is only putting out that. SO I don't know what effect accidentally swapping ALTC and altfr will do, it may indeed change the output but that wasn't my case I guess

out she comes!

I'm hoping I can get her out thru the top without removing booster and without removing axle.

I don't have much in my bag, might fit.

forbiddenera

Well THAT'S ODD

last ditch, for hell of it, curiosity I pull the alternator cable. Measure voltage AT the alternator terminal. Over 14 volts !

forbiddenera

Got brand new 4ga going to the fuse box .. but ya what the hell

*ohms the 4ga wire* ...