420A test voltage regulator

[Anubis_4_99]

Ok, so since i bought my RS i've been having on and off charging issues.

When i bought it guy told me the alt was bad, so i replaced it, put in a battery, and she ran great for a few months.

Then the battery light started coming on intermittently, but i could disconnect the battery and the alt would still run the system. Took it to oreillys and the guy argued with me about the regulator being bad and the alt needing replaced. I just let him warrenty it out and went on my way.

About a month ago i had an issue coming home from an out of town job, where my intake manifold ground broke, my alt severely overcharged my system, to the point where acid was bubbling out of the service caps (or whatever there called)

Fixed that, and she ran fine again for about a month, night before last the battery light came on, lights got dim, and she started loosing power. Got home, checked it over, unplugged the battery and car died. Yesterday took the alt out and went to oreillys again, tested bad and warrantied out.

New alternator in, battery light still comes on intermittently, but the alt will run the system again without letting the car die at idle. Battery light seems to come on anytime after 10 mins of driving, and after going over 3.5K RPM.

So i'm leaning towards my regulator being bad. But before i just replace the ECU i was wondering if there was a way i could test it? I have a meter, just need the info to test it, if it's possible.

 

[CODE4]

Ok, so since i bought my RS i've been having on and off charging issues.

When i bought it guy told me the alt was bad, so i replaced it, put in a battery, and she ran great for a few months.

Then the battery light started coming on intermittently, but i could disconnect the battery and the alt would still run the system. Took it to oreillys and the guy argued with me about the regulator being bad and the alt needing replaced. I just let him warrenty it out and went on my way.

About a month ago i had an issue coming home from an out of town job, where my intake manifold ground broke, my alt severely overcharged my system, to the point where acid was bubbling out of the service caps (or whatever there called)

Fixed that, and she ran fine again for about a month, night before last the battery light came on, lights got dim, and she started loosing power. Got home, checked it over, unplugged the battery and car died. Yesterday took the alt out and went to oreillys again, tested bad and warrantied out.

New alternator in, battery light still comes on intermittently, but the alt will run the system again without letting the car die at idle. Battery light seems to come on anytime after 10 mins of driving, and after going over 3.5K RPM.

So i'm leaning towards my regulator being bad. But before i just replace the ECU i was wondering if there was a way i could test it? I have a meter, just need the info to test it, if it's possible.

Not sure about testing the built in regulator, but I would recommend you install an external regulator and save yourself the cost of replacing the ECU.

http://www.electromotive-inc.com/pdf_files/neon99.pdf - Read Page 15.

 

[bullettdsm]

First see what voltage you are putting out at different rpm's. Be sure you are not overcharging the system (it sounds like you did at one point). If the regulator is good it will not allow you to overcharge (when mated with the proper alternator that is ). you can go straight to the output of the alternator if you want to check that.

And is it possible that you got 2 bad alternaors from O'Reilly's? Yup, totally possible.

MB

 

[Anubis_4_99]

First see what voltage you are putting out at different rpm's. Be sure you are not overcharging the system (it sounds like you did at one point). If the regulator is good it will not allow you to overcharge (when mated with the proper alternator that is ). you can go straight to the output of the alternator if you want to check that.

And is it possible that you got 2 bad alternaors from O'Reilly's? Yup, totally possible.

MB

I'm definitely not ruling out the possibility of getting bad alternators from o'reillys, but after 3 i would hope i would hit a good one. But either way, it's lifetime warranty so I'll just keep replacing it if it dies.

The reason I'm thinking my regulator is on its way out, is because i can go days, or sometimes weeks at a time without my battery light coming on. And then one day it will come on anytime i go over 3.5K rpms. And when this happens my alternator will still run the vehicle by itself at idle, and at speed, with the battery disconnected, even with my high beams, heater, and stereo on. So i know the alternator is at least doing its job.

I'm thinking the regulator is temporarily allowing either a voltage spike or drop at those times when my light comes on.

I'll check out the external regulator, only reason i haven't yet is because I've read a few threads where it didn't solve the peoples problems. It will probably be easier for me to source a regulator out here though then a new ecu. in the 5 month's I've been looking for an ecu I've only seen one like mine in the junkyard, and sadly i didn't have the cash to get it and it got crushed.

 

[CODE4]

I forgot to ask in my initial reply, but what voltages are you actually seeing? Do you have any form of voltage feedback - gauge or display of some kind? Or is all of this occurring solely off of the battery light for reference.

Check the voltage levels at varying RPMs as MB suggested. What is the voltage when the light flickers on? That should be the first thing you do...

 

[Anubis_4_99]

I will definitely check that when i can, i got called out of town for work so i wont be near the car until the weekend now, i will bump the post with numbers when i get back.

What would be the best spot to measure from? Positive terminal be ok? Or should i be going straight off the alternator?

 

[VelocitàPaola]

I'd measure it at the positive battery terminal...

 

[Anubis_4_99]

Voltage is rock solid at 14.68, can't get the battery light to come on while i'm testing, i plan to wire it up so i can monitor it while driving and hopefully the light comes on while i'm doing so, so that i can check for any spikes or drops.

 

[VelocitàPaola]

Voltage is rock solid at 14.68, can't get the battery light to come on while i'm testing, i plan to wire it up so i can monitor it while driving and hopefully the light comes on while i'm doing so, so that i can check for any spikes or drops.

That's a good idea.

In the future, I recommend not removing the battery while the car is running. That's sort of an old school trick to test the charging system in pre-EFI cars. The battery acts as a huge capacitor and filters a lot of the ripple the alternator creates. The ripple voltage can be as high as 4-6V under certain conditions; certainly not good for modern electronics.

 

[1983gsp]

Autozone carries a volts gauge that plugs into your cigarette lighter. Might be a simpler way of measuring volts instead of wiring something up. I would hate for you to burn your car up because the wiring wasn't fuse protected.

My .02

 

[Anubis_4_99]

Autozone carries a volts gauge that plugs into your cigarette lighter. Might be a simpler way of measuring volts instead of wiring something up. I would hate for you to burn your car up because the wiring wasn't fuse protected.

My .02

i'm using a volt meter. Nothing will be in danger of frying using something that was intended for that purpose.

And VelocitàPaola i know the removing the cables is kinda old school, but over the 40+ vehicles i've had, all the ones under 2000 haven't seen any ill effects from doing so, even so i vary rarely do it unless i absolutely need to know if its charging or not. Thanks for the heads up though.

With the eclipse i mainly did it because i was an hour from home and wanted to make sure my battery wasn't going to crap out on me before i could get back, didn't want to have to pay for a couple hundred dollar tow if it could make it home under its own power.

 

[Slo2gen]

How are you testing voltage while going down the road then if your using a DVOM? Your more likely to overcharge while driving than sitting still. And just for the record I put 3 diff alternators on my car from Autozone a good many years back, finally got tired to swapping them and just ordered one from the dealer. After that install, problem was solved.

 

[VelocitàPaola]

How are you testing voltage while going down the road then if your using a DVOM? Your more likely to overcharge while driving than sitting still. And just for the record I put 3 diff alternators on my car from Autozone a good many years back, finally got tired to swapping them and just ordered one from the dealer. After that install, problem was solved.

Here's my story: my stock alternator lasted for 120,000 miles. I only replaced it because a friend snapped the B terminal while we were swapping the engine. I replaced it with a standard alternator from Advance for around $150. Any 420A alternator under $200 is usually remanufactured, and sure enough, this one bit the dust less than a year later. I bought a brand new one for about $240 from NAPA and haven't had a problem since. Even though mine lasted a few months, it wouldn't surprise me if multiple remanufactured alternators were bad straight out of the box.

 

[Anubis_4_99]

How are you testing voltage while going down the road then if your using a DVOM? Your more likely to overcharge while driving than sitting still. And just for the record I put 3 diff alternators on my car from Autozone a good many years back, finally got tired to swapping them and just ordered one from the dealer. After that install, problem was solved.

Thank you for your input, however you contributed nothing to the thread i dont already know. If you have any info or ideas on testing the regulator, feel free to chime in, otherwise please dont. I'm well aware that the remaned alternator is a possible culprit, and if i had $200 laying around to just go buy a new one i would, but i don't and i have a lifetime warranty, so until i do i'll continue to replace this one.

Not trying to be an A-hole, i just already know that remaned alts are prone to failure. Although I've never had so many bad ones in a row through all the vehicles I've owned. And most have never needed replacing afterwards.

I'll be drive testing this weekend, so hopefully will have some numbers for ya in a day or two VelocitàPaola.

Does anyone have the part number or YMM of the car that i need a regulator from to go external? I'll be doing a search here soon for it, but if anyone knows off hand that'd be great.

 

[ktgurl87]

You know... just for grins and giggles. I have a n/t also, but my charging issue was caused by the cute little alternator fusible link (?) not being in correctly. Previous owner had broken one leg off then shoved a new one on top of it. It actually welded the little bolt that holds it onto the fuse box. What a mess that was to get out. But we did, and since I've put that new one in correctly I haven't had an issue.. even with a reman alternator

 

[VelocitàPaola]

1986-1988 Dodge Omni. Part number VR-125.

 

[Anubis_4_99]

Ill check on that fusable link, thanks for the heads up on that.

And i am deffinitly getting voltage spikes, the wife procedded to tell me that when i was out of town the cabin lights brightened and then both headlights blew and then the battery light came on, so i think i will for sure go for an external regulator. I havent gotten any numbers yet because it hasnt done it all weekend. But at this point with this new info i think getting a reading is pointless.

By the way thanks for the part number.

 

[CODE4]

I gave you the part number in that link a while back. Did you read the information?

 

[Anubis_4_99]

I read through it but must have missed the part numbrr, sorry about that.

 

[Slo2gen]

Not trying to be an A-hole

Not taken that way either but

I'm definitely not ruling out the possibility of getting bad alternators from o'reillys, but after 3 i would hope i would hit a good one.

I gave my experience with alternators from parts stores and since you said after 3 you figured you would have had a good one by now. Well I had 3 bad ones as well so there still was the possibiltiy (at that point in your diag) that you had a bad alternator.

the wife procedded to tell me that when i was out of town the cabin lights brightened and then both headlights blew and then the battery light came on

The headlights blowing could have been prevented(maybe) if you would have answered how you where measuring voltage while driving. You should have been able to see the voltage spike and know that the car didn't need to be driven(I know sometimes it cant be helped). Voltage spikes like that can also cause some serious issues with your entire system, from ecu to fuel pump so lets be glad you didn't fry anything else.

Not trying to be a A hole but, my post had valid points in it. I know a fellow member on 2gnt to have some issues like this and after he switched to an external regulator( 420A/Neon Alternator Voltage Regulator - SymTech Laboratories ) all of his problems went away. So hopefully the same will happen for you.

 

[Anubis_4_99]

Not taken that way either but



I gave my experience with alternators from parts stores and since you said after 3 you figured you would have had a good one by now. Well I had 3 bad ones as well so there still was the possibiltiy (at that point in your diag) that you had a bad alternator.



The headlights blowing could have been prevented(maybe) if you would have answered how you where measuring voltage while driving. You should have been able to see the voltage spike and know that the car didn't need to be driven(I know sometimes it cant be helped). Voltage spikes like that can also cause some serious issues with your entire system, from ecu to fuel pump so lets be glad you didn't fry anything else.

Not trying to be a A hole but, my post had valid points in it. I know a fellow member on 2gnt to have some issues like this and after he switched to an external regulator( 420A/Neon Alternator Voltage Regulator - SymTech Laboratories ) all of his problems went away. So hopefully the same will happen for you.

The headlights blowing happened while i was out of town before i started trying to diagnose this issue and had absolutely nothing to do with my means of measuring voltage.

I do thank you for the input, but until my alternator went out the other night i thought i had resolved the issue so i wasn't worried about driving it. Now its being driven only when needed until it is resolved. But being my only DD its hard to keep it out of service for too long. I plan to install the external regulator this weekend over my 4 weekend while i do my throw out bearing and rear mount and hopefully that will solve it.

 

[dsmvenge]

I have the same issue. Im going on my 7th alternator from Crapzone. time to go oem ftw