Car Is Almost Done, Alternator Issue

[raverboy]

Ok we are having trouble figuring out how to regulate the voltage on the alternator. My stock ecu is completely removed, and has been replaced with a haltech stand alone. But it does not have a feature that regulates the voltage flow of the alternator; reving the engine increases the voltage and so forth. Do any of you know what can be done to keep the alternators voltage from exceeding 12 volts and frying everything??? How can we stop the alternator from increasing voltage as the rpms increase???

 

[92awddsm]

The voltage regulator is built into the alternator. It should limit it somewhere around 14-14.5 volts.

 

[Siral3x]

YES no more then 14V, and it should not fry everything up!
The alternator is bad, just grab another one, unless you want to rebuild that you have.
It regulates itself..you can do nothing about it, unless you open it up and replace the regulator.

 

[luv2rallye]

Actually on the stock NT, the ECU entirely controls regulation. The turbo ones control it within the alternator itself (has different alt although there are 2 wires that also go to the ECU which I don't know what they are for). Since your listed as a "NT with turbo" I'm not sure what alt you've got. Does your alt have a 2 pin (NT) or a 4 pin (turbo) connector?

 

[92awddsm]

Actually on the stock NT, the ECU entirely controls regulation. The turbo ones control it within the alternator itself (has different alt although there are 2 wires that also go to the ECU which I don't know what they are for). Since your listed as a "NT with turbo" I'm not sure what alt you've got. Does your alt have a 2 pin (NT) or a 4 pin (turbo) connector?

Actually, all dsm's, 1g and 2g, turbo and n/t all have alternators with internal regulators. None of them have voltage regulated by the ecu.

 

[luv2rallye]

Actually, all dsm's, 1g and 2g, turbo and n/t all have alternators with internal regulators. None of them have voltage regulated by the ecu.

Then why does both the 2g DSM Backup Manual (p. 114) and my '99 Mitsu Eclipse manual (p. 90-46) both show the NT alternators have their field coil controlled by the ECU and show no regulator within the alt? (The turbo ones show the regulator within the alt - p. 116 or p. 90-48).

 

[92awddsm]

Then why does both the 2g DSM Backup Manual (p. 114) and my '99 Mitsu Eclipse manual (p. 90-46) both show the NT alternators have their field coil controlled by the ECU and show no regulator within the alt? (The turbo ones show the regulator within the alt - p. 116 or p. 90-48).

EclpzLvr97 can tell you because her voltage regulator went bad and was producing 16 volts. It was enough to burn up the charging teminal on the harness side. All that needed to be swapped was the alternator and replacing the charging terminal. Afterwards it put out 14.2 volts and the voltage readings were taken from the alternator itself. If the ecu controlled voltage, I would have had to replace the ecu, not the alternator. I have seen the n/t eclipse and the neon both have this problem. I have yet to hear of anyone having to replace the ecu because the voltage regulator failed. Book experience is far from hands on experience. And remeber, you cant always believe what you read regardless of where you read it.

 

[luv2rallye]

EclpzLvr97 can tell you because her voltage regulator went bad and was producing 16 volts. It was enough to burn up the charging teminal on the harness side. All that needed to be swapped was the alternator and replacing the charging terminal. Afterwards it put out 14.2 volts and the voltage readings were taken from the alternator itself. If the ecu controlled voltage, I would have had to replace the ecu, not the alternator. I have seen the n/t eclipse and the neon both have this problem. I have yet to hear of anyone having to replace the ecu because the voltage regulator failed. Book experience is far from hands on experience. And remeber, you cant always believe what you read regardless of where you read it.

Ok - well I don't have a 2g NT and haven't worked on one so I'm just going by the Mitsubishi (and DSM backup) manuals. They clearly state in writing that the 2g NT PCM (ECU) controls the field coil current (turning on and off) to maintain the output voltage at a constant level. They also show no regulator in the alt except for the turbo one. And the NT alt field coil is connected only to the PCM (ECU). For the turbo alt they talk about the alt's regulator controlling the field coil current. Since you've worked on one and say it's different I believe you and mean no disrespect. I'm just confused as to why Mitsubishi would have it wrong in their own manual all these years. Any ideas? If you pm me an email address that accepts attachments I can send you the pages. I would like to get this straightened out once and for all so I don't tell people wrong in the future and for my own knowledge. Are some 2g NT alt years different than others or are they different for different countries or trims or is the manual wrong for all of them or what? Anyone else know?

 

[raverboy]

Ok - well I don't have a 2g NT and haven't worked on one so I'm just going by the Mitsubishi (and DSM backup) manuals. They clearly state in writing that the 2g NT PCM (ECU) controls the field coil current (turning on and off) to maintain the output voltage at a constant level. They also show no regulator in the alt except for the turbo one. And the NT alt field coil is connected only to the PCM (ECU). For the turbo alt they talk about the alt's regulator controlling the field coil current. Since you've worked on one and say it's different I believe you and mean no disrespect. I'm just confused as to why Mitsubishi would have it wrong in their own manual all these years. Any ideas? If you pm me an email address that accepts attachments I can send you the pages. I would like to get this straightened out once and for all so I don't tell people wrong in the future and for my own knowledge. Are some 2g NT alt years different than others or are they different for different countries or trims or is the manual wrong for all of them or what? Anyone else know?

My shop is also stating that the ecu controlls the voltage in the alternator. My car is still being held up by this issue and I appreciate all of your guys help. They work on eclipses daily so they have a very good idea about the facts and parts on my car. However, there must be some way to control the volts in the alternator with something other then the stock ecu??? I cant believe that my haltech does not have any feature to do this?? Also, If there is any chance that the alternator does have a regulator then I must change it, only time and further investigation will tell.

 

[luv2rallye]

The 2g NT stock ECU changes the alt's output voltage slightly for different conditions as well as doing normal voltage regulation and it has no adjustment. I seriously doubt you will find anything that has adjustment since it is a rather complex and expensive circuit that controls the alt's field coil current (not just a simple variable resistor) and there are many conditions that only the ECU would know. You will probably have to either hook up the stock ECU to just control the alt or buy a 90A one for a turbo (since your NT one is 90 and normal turbo ones are 75), change it's electrical plug, and hope it fits (I don't know if it will or not). You could also ask others on here who have a setup like yours what they did.

BTW I asked a wiseman dsm mechanic and he confirmed that 2g NT alt's don't have a voltage regulator in them and that it is controlled by the ECU just as I said. This is because Chrysler made the 2g NT. Alt's without regulators in them can go bad just as easily as alt's that do have them. And the ECU will be uneffected (it has protection against bad alt's).

 

[MrGriff750]

All alternators have regulators built internally...

 

[99gst_racer]

All alternators have regulators built internally...

Wrong.

All alternators are regulated, but they are not all internal. Even the old GM 1-wire alternators are available in either internal or external regulated.

 

[Old Mitsu Tech]

Turbos are internally regulated. Non turbos are regulated through the power train control module. It's a Chrysler thing. It seems they have a penchant for the pcm controlling everything. They have been doing this for years. Started on their regular lines. Then when Mitsubishi started using their 420a engines it gravitated to you non turbo guys. Same as the Cirrus and Stratus. Exactly.

 

[steve]

Turbos are internally regulated. Non turbos are regulated through the power train control module. It's a Chrysler thing.

Rather than say it's a turbo vs non-turbo thing it's really a Chrysler vs Mitsubishi thing. All the Mitsu engine based alternators we use are internally regulated where the Chrysler engine based alternators are externally regulated. There are plenty of 1g NA and 2G spyders that have internally reglated alternators.

Steve

 

[Old Mitsu Tech]

I agree. Chrysler has been pcm regulating for years. You can imagine the individual's look of surprise and disgust when their alternator quits charging and I have to tell it's their computer which won't allow the alternator to charge. And the fact it's about 3 times as much to repair. Not to mention that almost no one has the pcm's in stock as they changed the design almost every year which made stocking almost impossible.

 

[Doug99RS]

ELECTRONIC VOLTAGE REGULATOR
The Electronic Voltage Regulator (EVR) is not a separate component. It is actually a voltage regulating circuit located within the Powertrain Control Module (PCM) The EVR is not serviced separately. If replacement is necessary, the PCM must be replaced.

Operation: The amount of DC current produced by the generator is controlled by EVR circuitry contained within the PCM. This circuitry is connected in series with the generators second rotor field terminal and its ground.

Voltage is regulated by cycling the ground path to control the strength of the rotor magnetic field. The EVR circuitry monitors system line voltage and battery temperature (refer to Battery Temperature Sensor for more information) It then compensates and regulates generator current output accordingly. Also refer to Charging System Operation for additional information.

That's straight from the Chrysler website.

 

[luv2rallye]

EclpzLvr97 can tell you because her voltage regulator went bad and was producing 16 volts. All that needed to be swapped was the alternator and replacing the charging terminal.

How does replacing the alternator which fixed the problem prove 1) it's a bad regulator and 2) the regulator is in the alternator? You maintain both of these are true yet many experts have proven you wrong on this 2g NT. An alternator can go bad whether it has an internal regulator or not. You made 2 invalid assumptions, fess up and admit it.

If the ecu controlled voltage, I would have had to replace the ecu, not the alternator. I have seen the n/t eclipse and the neon both have this problem. I have yet to hear of anyone having to replace the ecu because the voltage regulator failed.

Ah yes, another bad assumption but I forgot, you have more experience than others. And you obviously don't hear too well either (or care to listen - well now you can hear for the first time about replacing the ECU because the voltage regulator failed in post 15 from THE EXPERT).

Book experience is far from hands on experience.

Doesn't seem so in this case now does it?
Maybe you should check the book more often before you brag about your experience being always correct. I'm not trying to cut you down here - we all make mistakes and can't know everything about every model. Everyone (including me which I did) should always check the facts first before offering advice on someone's dsm problem, especially if it's a different model than we have.

All alternators have regulators built internally...

Before making grandiose "all" statements like this check your facts. You not only look foolish when proven wrong but you are giving false information which is against the rules and misleads others.

And remeber, you cant always believe what you read regardless of where you read it.

Boy ain't that the truth!

 

[raverboy]

Thank you guys for all of your help. Currently my shop is pulling off the alternator and taking it to a different location to get some sort of external regulator installed. The car idles perfectly and this is my last hurdle of a long long, EXPENSIVE project.

Any other alternative suggestions besides rewiring a stock ecu into the system??