2G alternator issue

[silvercoupe97]

Ok, I just replaced a bad alternator. I just wouldn't charge the battery.
The new one I have won't charge it either. I've checked both bolt on fuses and the most inner fuse is hot at all times while the most outer fuse won't even light my check light. I checked the fuse with the car on and off and still a no go. Is there something inbetween the alternator and that fuse, is there something between that fuse and the battery? I thought that both those fuses should be hot at all times.
The alternator has a 4 wire plug, if that helps. I know that the 1Gs have relays, do the 2Gs? I don't remember reading whether it does or not in my Chiltons, CD manual, or the net...only the 1Gs.
Any help would be appreciated.

Here's something I just noticed, in relation to the two 100amp fuses. The outer fuse has two bolts on either side, while the inner fuse only has one and it's on the front side. Should it have a bolt on the back side too? No guesses on this one please.

TIA,
John

 

[silvercoupe97]

All right, I took my car to the place that I got the alternator from and they hooked up their ammeter and voltmeter machine thingy. Their inductive ammeter read -004 (I don't know where the decimal point is in that value) and the voltmeter read 12.03 all the while bouncing to 11.9volts, my TT read the same. Other things I noticed on the way there was my charge or battery light coming on brighter during higher rpms and dimming on lower rpms. My windows also were working on the way there.
Then I got there and they did there thing.
Here's a kicker....on the way back, I noticed my volts were now at 11.3-11.5volts but the battery light was no longer on and my windows were working again! Good thing too because without A/C, it gets hot in there and the sunroof only let out so much hot air.
So...why did the battery light not come back on and why did my windows work again?
I'll take just the alternator to them tomorrow and replace it and get back to you guys to finish this thread.

 

[Defiant]

Ok, I just replaced a bad alternator. I just wouldn't charge the battery.
The new one I have won't charge it either.

It's dead, too. It happens.

 

[silvercoupe97]

It's dead, too. It happens.

Yeah, it sucks too. Good news is...with a fully charged battery (house charger) and a strong one at that, she runs GREAT! This leads me to believe that the battery and alternator were on the way out. I've still got to take the 2nd one out and get my replacement tomorrow. The guys that checked were stumped on why this newer one was doing the same thing.

Anyone know this..

Here's something I just noticed, in relation to the two 100amp fuses. The outer fuse has two bolts on either side, while the inner fuse only has one and it's on the front side. Should it have a bolt on the back side too?

 

[luv2rallye]

Here's something I just noticed, in relation to the two 100amp fuses. The outer fuse has two bolts on either side, while the inner fuse only has one and it's on the front side. Should it have a bolt on the back side too?

No, the back side has a plate so the 1 large wire connects to both.

BTW my car (turbo) has a 60A in outer and 100A in inner. (NT have 120A outer and 60A inner.) Are you sure you have the proper fuse?

 

[silvercoupe97]

No, the back side has a plate so the 1 large wire connects to both.

BTW my car (turbo) has a 60A in outer and 100A in inner. (NT have 120A outer and 60A inner.) Are you sure you have the proper fuse?

Thank you for your reply on that Luv2rallye, that's good to know. Mine is the same then, cool. The only thing is that the large wire only passes through the outer fuse and not the inner on mine and that plate is insulated so it doesn't pass electrically to the inner fuse. I looked at my CD manual and Chilton's and dug for info, the schematics show the two to be electrically connected and that both fusible links should be hot at all times....and on mine, the inner fuse is the only one hot at all times, while the outer is just dead at all times. This makes me think that I need to attach a screw/bolt, with the same thread pattern, on the back of the inner fuse so that both sides are hot all the time.
As for the fuse ratings, that's what was in there so I assumed they were correct. Thanks for posting your fuse ratings bro.

I do have my vehicle profile filled in, but mines a hybrid and that's why it doesn't show my car under my name, but I have 95 GSX underpinnings

 

[luv2rallye]

Since yours is a hybrid be careful what you change. Is all your engine compartment wiring only from a stock '95? Did it ever work? Was anything rewired to handle non stock stuff? When you change anything I suggest temporarily putting a 12V light bulb in series with one of the battery terminals to see if you have a short or current draw before you start melting things or blowing fuses.

On my '99 the rear of the 2 fuses (100A & 60A) is not just a plate but a bus bar that goes into the fusebox to other fuses. It also has the two 10ga white wires that go to the alternator. The front of the inner fuse (100A) has two 10ga white wires that go to the battery. The front of the outer fuse (60A) has 10ga white/black wire that goes to other fuses. The other two 10ga white wires from the battery go to a different bus in the fusebox.

 

[silvercoupe97]

Since yours is a hybrid be careful what you change. Is all your engine compartment wiring only from a stock '95? Did it ever work? Was anything rewired to handle non stock stuff? When you change anything I suggest temporarily putting a 12V light bulb in series with one of the battery terminals to see if you have a short or current draw before you start melting things or blowing fuses.

On my '99 the rear of the 2 fuses (100A & 60A) is not just a plate but a bus bar that goes into the fusebox to other fuses. It also has the two 10ga white wires that go to the alternator. The front of the inner fuse (100A) has two 10ga white wires that go to the battery. The front of the outer fuse (60A) has 10ga white/black wire that goes to other fuses. The other two 10ga white wires from the battery go to a different bus in the fusebox.

Yes, the wiring is from a stock 95 harness (which was swapped to replace the 6G73 harness), yes..it was working until about a week ago, no..nothing was rewired (well, the CAS was rewired to the 95 harness). I'll have to look at what's connected on those two links, your description sounds about like mine though.

Well, I had a moment to have my alternator checked and it checked good, except for its grounding post. No worries though, I can just ground it onto the pivot bolt (though I don't understand why this is even an issue since it's all grounded to the motor). The machine read 13.9 volts while grounded to the grounding bolt (on the alt), while it read 14.2 on the alt body (again, weird since it's all grounded to the same place in the end).
So my issue lies in the ground to the block, battery ground, ECU (that's questionable though since it has nothing to do with the regulator and my battery light works, but I thought to throw that out there).
So, I'm going to test all the grounds, make a new one for the motor and alternator, and reinstall the alternator...again. I feel like I'm on with this issue.

I do appreciate your help on this luv2rallye

 

[luv2rallye]

So my issue lies in the ground to the block, battery ground, ECU (that's questionable though since it has nothing to do with the regulator and my battery light works, but I thought to throw that out there).
So, I'm going to test all the grounds, make a new one for the motor and alternator, and reinstall the alternator...again.

I've always assumed you have the turbo, correct? Your reference to a regulator with the ECU bothers me since the voltage regulator on the turbo is in the alternator but on a 2g NT is in the ECU. So what are you referring to?

A couple of other things I'm not clear on:
1) Did you replace the battery? If not, how old is it and did you have it actually load tested somewhere? A weak battery (eg. 1 partially dead cell) can make the alternator appear bad and give strange voltage readings.
2) Is your ECU for a '95 turbo dsm?
3) To test the outer fuse that you claim is not hot, did you physically remove it and check it's continuity with an ohmmeter? Is there any voltage at either end of it's holder? If not, unbolt the fusebox and look under it to see where exactly the wires go that connect to it and their color.
4) What was done or happened between the time everything worked correctly and when it didn't? Was anything disconnected or put in wrong or did you see any sparks or unusual things when something was connected or disconnected?
5) Your idea of checking grounds is good and could easily be your problem. See here for how info: http://www.dsmtuners.com/forums/showthread.php?t=179916 (and for shorts here: http://www.dsmtuners.com/forums/showthread.php?t=179481).

 

[silvercoupe97]

Ok, so it's in and it still reads the same at first.
The interior lights aren't on at all when the volts are below 12volts according to the TT (inside voltage). I also don't know what that bellow is on the firewall but when I connected the two fuses together with my test light it clicked and my internal lights came on . It most likely has nothing to do with anything, other than it received power somehow. Another thing to note is that after doing that, it must have reset something because both sides are hot (has 12volts) with the motor running. Another thing I noticed is that, for a split second after putting my test light on both fuses, my test light tip was red hot. That to me means that those two shouldn't touch...ever again. I did reset something though and that makes me believe that there's a relay somewhere that's sticking, but I thought that they were only on the 1Gs. Well, I'm going to go and mess with that saucer/bellow thing some.

One thing to note is that my 95 has ODBII but also has the bigger vented brakes, I'm not sure if that means anything, but I guess any and every info helps.

 

[silvercoupe97]

I've always assumed you have the turbo, correct? Your reference to a regulator with the ECU bothers me since the voltage regulator on the turbo is in the alternator but on a 2g NT is in the ECU. So what are you referring to?

A couple of other things I'm not clear on:
1) Did you replace the battery? If not, how old is it and did you have it actually load tested somewhere? A weak battery (eg. 1 partially dead cell) can make the alternator appear bad and give strange voltage readings.
2) Is your ECU for a '95 turbo dsm?
3) To test the outer fuse that you claim is not hot, did you physically remove it and check it's continuity with an ohmmeter? Is there any voltage at either end of it's holder? If not, unbolt the fusebox and look under it to see where exactly the wires go that connect to it and their color.
4) What was done or happened between the time everything worked correctly and when it didn't? Was anything disconnected or put in wrong or did you see any sparks or unusual things when something was connected or disconnected?
5) Your idea of checking grounds is good and could easily be your problem. See here for how info: http://www.dsmtuners.com/forums/showthread.php?t=179916 (and for shorts here: http://www.dsmtuners.com/forums/showthread.php?t=179481).

Oh, yeah, sorry.
1. I do have a new battery...1 week old now. Battery is in the rear btw with a 100amp circuit breaker sitting in the old battery spot.
2. It is a 95 AWD turbo with an EPROM ECU.
3. See, post below yours. The outer fuse = forward bolt has a single white with black stripe...rear bolt has two white wires. The inner fuse = forward bolt has two white wires...nothing connected to the rear bolt area.
4. The last thing I did was remove my DV pipe and reinstall it. No sparks or sounds were noted. The usual moving of wire bundles but nothing odd.


Sorry to confuse, I'm a bit confused too. I know that the regulator is in the alternator, I was just throwing that out there.


I just checked the grounds and they are good in every spot of the motor to chassis and the battery is grounded good too.
The battery light hasn't came on today while in the driveway. The battery seems to hold steady at 11.9volts to 11.5volts, depending on the load, but it's still dwindling.

 

[luv2rallye]

I also don't know what that bellow is on the firewall but when I connected the two fuses together with my test light it clicked and my internal lights came on ..

I have no idea what this bellow on the firewall you refer to is. A relay perhaps from the old hybred stuff? Describe it better. Have a picture?

Another thing to note is that after doing that, it must have reset something because both sides are hot (has 12volts) with the motor running. .

Both sides of the fuse that was not hot before?

Another thing I noticed is that, for a split second after putting my test light on both fuses, my test light tip was red hot. That to me means that those two shouldn't touch...ever again. .

Why and how did you do that? Just shorting the two with one probe tip? Dangerous! Being red hot means either they should not be together (most likely) or there is more current flowing than your test light probe can handle.

I did reset something though and that makes me believe that there's a relay somewhere that's sticking, but I thought that they were only on the 1Gs.

Well there's a MFI relay but that just gives power to the engine, not the interior. You having a hybred bothers me since I have no idea what's dsm and what's not (electrically). How about PMing me?

 

[silvercoupe97]

I have no idea what this bellow on the firewall you refer to is. A relay perhaps from the old hybred stuff? Describe it better. Have a picture?



Both sides of the fuse that was not hot before?



Why and how did you do that? Just shorting the two with one probe tip? Dangerous! Being red hot means either they should not be together (most likely) or there is more current flowing than your test light probe can handle.



Well there's a MFI relay but that just gives power to the engine, not the interior. You having a hybred bothers me since I have no idea what's dsm and what's not (electrically). How about PMing me?

I forgot to mention that everything that had the mitsu 6g73 attached to it was removed. The engine bay was gutted of it and was replaced by the mitsu 4g63 and it's harness, to include all the peripherals and it's wiring...except forward lighting harness which was spliced with the Eclipse harness so that the headlights and such would still work and that they were the same except the plugs.

Oh and both sides were not hot with the car running...at first, but when I shorted the two posts, it reset something and both sides were suddenly hot. The alternator fuse also read 15volts this time..earlier I was getting ~1-2volts. The battery side remained the same at 12volts...that also came down from 12.5volts after idling for about 5 minutes. The idle isn't rough either....not sure if that means anything.

 

[silvercoupe97]

Here's another anomaly!...I just rechecked the fuses and ohmed them out. They checked good. I put them back in and accidentally pushed the bolts and the bus plate down a bit and I thought to myself...great, now I'm going to have to take the fuse box apart and push them back up (I'm a bit of a perfectionist). Well, I reset the CB because I popped it so that I wouldn't zap myself or blow fuses. Anyway, I check for power with my trusty check light on the battery fuse and the just for poops and giggles the alternator fuse too...and guess what?!!!! Both sides are hot now!???? So I started the car to check interior voltage and my TT reads 13.7 or something like that...it read higher than 11.5 and that's what matters right? .
I think that both fuses should be connected and some how either the rear bolt fell off from vibrations or something because both should be hot at all times like the book and CD manual shows. I'm about to check it again to make sure I haven't inhaled too much exhaust fumes though and make sure that the fuse box isn't melted.
My issue was the alternator and bad connections then? I know the old alternator was bad because the bearings were shot and loose. I just don't, for the life of me, remember there being a bolt on the rear side of the inner fuse.

 

[luv2rallye]

I put them back in and accidentally pushed the bolts and the bus plate down a bit and I thought to myself...great, now I'm going to have to take the fuse box apart and push them back up (I'm a bit of a perfectionist). Well, I reset the CB because I popped it so that I wouldn't zap myself or blow fuses. Anyway, I check for power with my trusty check light on the battery fuse and the just for poops and giggles the alternator fuse too...and guess what?!!!! Both sides are hot now!????........I think that both fuses should be connected and some how either the rear bolt fell off from vibrations or something because both should be hot at all times like the book and CD manual shows.

Look underneath the fusebox (unbolt it). Maybe on the '95 they connected the 2 rears of the fuses underneath somehow ('99 is on outside) and they got loose. You will have to look under and tighten/fix or this problem will keep occuring.

 

[silvercoupe97]

As I said in the pm to you luv2rallye, I greatly appreciate your help and thank you for stepping up to the plate and for taking the time out of your day/night to help me in my time of need bro.

Thank you again bro,
John

Issue solved..

 

[justin0469]

I am having a similar issue ever since I have had my car. I bought 4gauge wire to replace the ones coming off the battery for a few reasons and hope to cure my problem along the way. I am confused about the battery wires coming to and from the fuse box though.

It also has the two 10ga white wires that go to the alternator. The front of the inner fuse (100A) has two 10ga white wires that go to the battery. The front of the outer fuse (60A) has 10ga white/black wire that goes to other fuses. The other two 10ga white wires from the battery go to a different bus in the fusebox.

So if I want to replace the wires going to my alternator from the battery, how would I just take away the positive to the alternator (to run my own wire w/ inline fuse directly to it) but still allow these other fuses and things to get power they apparently get from the same wire? Any ideas about running new wires to the starter as well with an inline fuse?

 

[luv2rallye]

So if I want to replace the wires going to my alternator from the battery, how would I just take away the positive to the alternator (to run my own wire w/ inline fuse directly to it) but still allow these other fuses and things to get power they apparently get from the same wire? Any ideas about running new wires to the starter as well with an inline fuse?

First of all the stock alternator + does not go directly to the battery + on a '98 turbo dsm. It goes to the 100A fuse in the engine fusebox via two 10ga white wires. The other side of that 100A fuse goes to battery + through two different 10ga white wires. Don't get confused as there is also a third set of two other 10ga white wires that go from battery + to a different place in the fusebox - ie. so battery + has two sets of two 10ga white wires - ie. 4 white wires that all go to the fusebox, each set to a different place. You can disconnect the alternator + (at the alt) and put your own wire from there to battery + as long as you have an inline fuse. And you can just leave the old alternator wires there as long as you tape them up at the alternator end.

As to starter inline fuse see my post on your other thread.

 

[justin0469]

I didn't mean to imply that I thought that there was a direct line from the alternator to the battery on the stock setup.

Just to reiterate what you said to make sure I understand, it goes something like this: B+ > 2 white wires > 100A fuse > 2 white wires > alternator and B+ > 2 white wires > power supply to fuse box

So if I just don't connect the 2 white wires going to the alternator fuse, I won't have to worry about a hot wire bouncing around.

 

[luv2rallye]

Just to reiterate what you said to make sure I understand, it goes something like this: B+ > 2 white wires > 100A fuse > 2 white wires > alternator and B+ > 2 white wires > power supply to fuse box

Yes but I don't know what you mean by "power supply". Those other 2 white wires just go to a different place (and different fuses) in the engine fusebox than the first 2 white wires from battery +.

And the 100A fuse is not just for the alternator. In addition to the alt's 2 white wires, it also goes into the fusebox to 3 other fuses (so it is not just an alt fuse).

So if I just don't connect the 2 white wires going to the alternator fuse, I won't have to worry about a hot wire bouncing around.

Correct, just make sure you disconnect the correct pair since there are 3 sets of white wires. And disconnect the battery before doing any of this.

 

[justin0469]

Yes but I don't know what you mean by "power supply". Those other 2 white wires just go to a different place (and different fuses) in the engine fusebox than the first 2 white wires from battery +.

I misunderstood and thought that the other wires supplied a general power supply to the fuse box, giving all the other fuses the + they need

And the 100A fuse is not just for the alternator. In addition to the alt's 2 white wires, it also goes into the fusebox to 3 other fuses (so it is not just an alt fuse).
Correct, just make sure you disconnect the correct pair since there are 3 sets of white wires. And disconnect the battery before doing any of this.

Ok, that is what I thought from the beginning, that it was not just the alternator on that line. So I still need to supply + to that fuse and just take off the 2 wires after the fuse for the alternator. I appreciate your help and patience Please continue to correct me if I am wrong.