2G 90A Galant Alternator charging issues

[kyler021]

Hey guys,
I just installed a 90A alternator last weekend from a 96 Galant and its been having voltage issues ever since. At the same time I installed the alternator I redid the battery ground to the firewall and installed a new Optima RedTop battery.

Now to my specific problem: using ECMLink I was monitoring battery voltage after install, and noticed that once coolant warmed up to around 120 degrees the alternator would stop charging and would show ~12.8V (before that point battery voltage was 14.5V). When it went to 12.8V I noticed that the interior lights dimmed. When the engine was revved up to 1500+ RPM it shot back up to 14.5V and interior lights got bright again. I also noticed after the next cold start up that battery voltage would jump between 12.7V to 14.5V when coolant warmed up to ~120 degrees. Battery voltage when cruising seems to be 14.5V as the RPM is above 1500.

The alternator I installed is a BBB Industries 90A 1996 Galant Alternator.

This new alternator also seems to have a second ground post (?) on the lower part, that the old alternator did not have. Should I try grounding this or does it seem like a voltage regulator issue? Attached are pictures of the new battery, ground cable and alternator. As you can see in the picture of the alternator, there's a stud and two nuts in the lower left of the picture (I'm wondering if that's another thing I need to ground in order to fix it). Has anybody else had this issue before?

Any help is appreciated!

You must be logged in to view this image or video.

You must be logged in to view this image or video.

 

[dwb]

You should have a ground from neg battery post to the upper starter bolt, which grounds the block. I can't tell if that's what the black and yellow cable is for. The alt receives it's ground from the block, but wouldn't hurt to ground it separately too.

Not sure if this also relates to your charging issue, but those battery terminals are less than ideal. They can cause galvanic corrosion (dissimilar metal corrosion) and have been known to cause voltage issues. See if you can find some of the OEM style with a stud and wing nut, then install an eyelet lug, like your red ground cable, on the ends of all your cables.

Be careful not to mix up the positive and negative since your cables are colored backwards.

 

[RamenPride]

The two white wires that were on the factory positive post/terminal need to have their own connection directly to the battery. Looks like you've got one wire going to the starter, but combined the rest from the fuse box using one big wire.

Edit: maybe not both wires, refer to Post #3

 

[99dsmer4g63]

I think your alternator is functioning the way the factory intended it to. I think you’ll notice also that anytime you have maybe 25% throttle it will charge and if you let off the throttle and the IPS engaged it will charge.

Read Steve’s 2nd post and read the ECMTuning link he posted.

1G - ECMLink tuning and battery voltage dropping

1992 Plymouth Laser, engine was built pistons, 274 cams, springs, valves, not sure of piston's for compression ratio. AFPR at 42.5, PTE 880 injectors new 200kms, AEM fuel rail, Garrett 60-1 turbo, FMIC, long intake filter, Walbro 255 with rewire mod, NGK BPR7s, external WG, 3" exhaust back...

www.dsmtuners.com

This is why my alternator is clipped forcing high voltage mode constantly.

-Daniel

 

[DSMPT]

Now to my specific problem: using ECMLink I was monitoring battery voltage after install, and noticed that once coolant warmed up to around 120 degrees the alternator would stop charging and would show ~12.8V (before that point battery voltage was 14.5V). When it went to 12.8V I noticed that the interior lights dimmed. When the engine was revved up to 1500+ RPM it shot back up to 14.5V and interior lights got bright again. I also noticed after the next cold start up that battery voltage would jump between 12.7V to 14.5V when coolant warmed up to ~120 degrees. Battery voltage when cruising seems to be 14.5V as the RPM is above 1500.

This sounds normal with 2g. My 2g does it, too. You should also see the voltage up when turning on the headlights, A/C, radiator fan, etc

Should I try grounding this or does it seem like a voltage regulator issue?

Not related. You can ground it but you don't need to.

 

[jed344]

Myself and some other local guys have been using the 90 amp Galant alternator for years. Some cars act this way and other do not. I am not exactly sure why. Now that I think of it most act this way but for some reason mine with a likely 8 year old 90 amp idles at 13.8-14.3 solid and does not do this. Many others though I have seen though drop voltage. I always assumed it was voltage regulator issue.

Though the car's and mine that do not do this also idle at 1050-1200rpm due to very aggressive cam's so maybe they just are high enough in rpm's.

 

[99dsmer4g63]

@jed344 I’d be curious to know if you see a relationship between the ones that do and the ones that don’t with the year of ECU.

I feel like with the factory 99’ black box in two different cars and 2 different black boxes I never noticed it.

There was a brief time I had a 97 ECU running factory injectors in my car while breaking in the motor and instantly noticed.

Since switching to a 95 EPROM with ECMLink I also noticed it which is when I figured out how to force “high” voltage mode all the time.

Only issue I’ve ever noticed with it is sometimes on a hot restart the voltage will spike to high 15’s for a split second to where if I wasn’t monitoring it you wouldn’t even notice. I seen another member mention his does this as well when forcing high voltage mode.

-Daniel

 

[miliman13]

Do you have a clamp multimeter? Just to see what your amps at idle are, I recently tested mine and measured 20 amps

From what I have seen online depending on vehicle 10-20 is an acceptable range.

Possibly unrelated but I mentioned it since I did an alternator rewire with an inline fuse and stopped having charging issues long ago.

 

[chrisman287]

I had a brand new BBB or Remy that was bad right out of the box. Voltage looked ok in link at start up but the brake and battery light were on as if it wasn’t charging. When trying to drive voltage would drop to the upper 12s. I disabled the error code in link and the problem persisted.

I got a used OEM Galant alternator and haven’t had an issue since. The pulley on it did look a bit smaller than my stock alternator tho. I’m thinking about trying a slightly smaller belt.

 

[dwb]

I got a used OEM Galant alternator and haven’t had an issue since. The pulley on it did look a bit smaller than my stock alternator tho.

Same here but two reman 1g 90a Galant. I figure the smaller pulley is better for voltage at idle.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

 

[kyler021]

See if you can find some of the OEM style with a stud and wing nut, then install an eyelet lug, like your red ground cable, on the ends of all your cables.

You must be logged in to view this image or video.

Something like this style of terminal would be ideal?

This sounds normal with 2g. My 2g does it, too. You should also see the voltage up when turning on the headlights, A/C, radiator fan, etc

The voltage also doesn't change when I turn on all the accessories I have. I forgot to mention that in the original post. Usually when all accessories are on its about 12.7-12.8 at an 1100 rpm idle.

Though the car's and mine that do not do this also idle at 1050-1200rpm due to very aggressive cam's so maybe they just are high enough in rpm's.

I'm idling around 1100rpm through ECMLink as anything lower than that without balance shafts is just awful haha.

Do you have a clamp multimeter? Just to see what your amps at idle are, I recently tested mine and measured 20 amps

I do, I'll check this and see what's up

I had a brand new BBB or Remy that was bad right out of the box.

Interesting, I try to do my research before and was told BBB was okay. Maybe I got a dud. And the alternator test sheet they send out with the alternator says it's from July 2023 which made me wonder why it was sitting around for so long. Maybe a Reman ACDelco would've been a better choice?

 

[jed344]

@jed344 I’d be curious to know if you see a relationship between the ones that do and the ones that don’t with the year of ECU.

I feel like with the factory 99’ black box in two different cars and 2 different black boxes I never noticed it.

There was a brief time I had a 97 ECU running factory injectors in my car while breaking in the motor and instantly noticed.

Since switching to a 95 EPROM with ECMLink I also noticed it which is when I figured out how to force “high” voltage mode all the time.

Only issue I’ve ever noticed with it is sometimes on a hot restart the voltage will spike to high 15’s for a split second to where if I wasn’t monitoring it you wouldn’t even notice. I seen another member mention his does this as well when forcing high voltage mode.

-Daniel

These car's all have 95 EPROM ECUs. I do not think we have ever used one on a black box or even a non-EPROM metal case ECU conversion. The car's are all 97+ cars with 95 ECU's. I never considered somehow the ECU may have a effect on this.

The one local car that is a 99 with a 95 ECU did not have the voltage drop but it would surge lights at start up and also at wide open the voltage would jump around. Saw as high as almost 16v at wide open. That was fixed by getting another alternator. These all where just cheap O'reillys alternators. These local car's and mine also all have been confirmed voltage from either turbo timer or multi-meter too. ECMLink matched our secondary way to check it.

 

[chrysler kid]

it doesnt matter the brand, bench testing any alternator is nothing compared to having it running next to a glowing down pipe underneath your powersteering pump.

you can bench test them all day, go on a hot drive and then take the car up to your local autoparts store and have them do an alternator test while the vehicle is warm and running.

these remans are all typically junk. make sure you are buying one locally that is backed with a warranty so they will replace it when it goes out.

and put your stock non 90amp one back on the car if the new one is causing you problems. if it quacks like a duck its usually because its a duck and not because there is an ecu problem on a chicken that makes it sound like a duck

 

[FIBA M - EC17PSE]

it doesnt matter the brand, bench testing any alternator is nothing compared to having it running next to a glowing down pipe underneath your powersteering pump.

you can bench test them all day, go on a hot drive and then take the car up to your local autoparts store and have them do an alternator test while the vehicle is warm and running.

these remans are all typically junk. make sure you are buying one locally that is backed with a warranty so they will replace it when it goes out.

and put your stock non 90amp one back on the car if the new one is causing you problems. if it quacks like a duck its usually because its a duck and not because there is an ecu problem on a chicken that makes it sound like a duck

Agree on the temp part! I have an oem one that works on bench testing but once hot fails. The testing place could not understand this and kept passing it as fine. Heat can have a massive effect and sometimes ots often overlooked as part of the problem.

 

[kyler021]

The two white wires that were on the factory positive post/terminal need to have their own connection directly to the battery. Looks like you've got one wire going to the starter, but combined the rest from the fuse box using one big wire.

I apologize for the late question, but could you clarify a bit more about what you mean by "combined the rest from the fuse box using one big wire."? I wasn't sure about what you meant by the white wires, but maybe you're onto something with these battery cables being bad / connected incorrectly.

I haven't changed the cables during my ownership but since I'll be replacing the starter soon, I'm going to see if these battery cables are my problem. My guess is whoever replaced these cables last didn't connect it like the factory did and it's causing some weird issues. (voltage issues, gauge cluster lights dimming when blinker is on, fuel pump whining down when blinker is on, etc). Once the weather gets better I will take it on a hot drive and stop by the auto parts store and have them test the alt.

On another note, I read somewhere else that any alternator rated over 100A needs a bigger cable going to it. Could this possibly be contributing to my problem?

Thanks!
Kyle

 

[RamenPride]

I apologize for the late question, but could you clarify a bit more about what you mean by "combined the rest from the fuse box using one big wire."? I wasn't sure about what you meant by the white wires, but maybe you're onto something with these battery cables being bad / connected incorrectly.

I haven't changed the cables during my ownership but since I'll be replacing the starter soon, I'm going to see if these battery cables are my problem. My guess is whoever replaced these cables last didn't connect it like the factory did and it's causing some weird issues. (voltage issues, gauge cluster lights dimming when blinker is on, fuel pump whining down when blinker is on, etc). Once the weather gets better I will take it on a hot drive and stop by the auto parts store and have them test the alt.

On another note, I read somewhere else that any alternator rated over 100A needs a bigger cable going to it. Could this possibly be contributing to my problem?

Thanks!
Kyle

https://www.dsmtuners.com/threads/alternator-charging-low.546344/post-153913378