Alternator regulator keeps dying
Alternator regulator keeps dying I have only 1000 miles on my LS swap and I'm on my third alternator. I have a light bulb on switched power that is wired to the "L" terminal for field excitation. Both alternators had unstable charging voltage just a little while before failing and then turned off completely. After failing, the light bulb does not come on, indicating an open circuit failure in the regulator. And frankly, I thought the charging voltage was always too high even when the alternators did work. Seemed to put out 14.8V - 15V nearly all the time, which will overcharge a battery in warm weather.
Anybody else failing alternators like this? I see people complaining about symptoms related to undersized alternator but that is not the problem I am having. Mine just flat out stop working altogether. My wiring is very robust and not a problem.
Anybody else failing alternators like this? I see people complaining about symptoms related to undersized alternator but that is not the problem I am having. Mine just flat out stop working altogether. My wiring is very robust and not a problem.
Last edited by QwkTrip; Oct 9, 2016 at 02:17 AM.
I'm wondering if I need to knock down the current on the excitation circuit. The current has to be limited or the regulator will be damaged. A 50 Ohm resistor is suitable, and the light bulb I use is a #194 which is about 50 Ohm when hot but is a lot less until it gets hot. I do a lot of key-on events to download datalogs and fiddle with my tune. I think I will put another 50 Ohm resistor in the circuit just to make sure the current is never too high.
I'm wondering if I need to knock down the current on the excitation circuit. The current has to be limited or the regulator will be damaged. A 50 Ohm resistor is suitable, and the light bulb I use is a #194 which is about 50 Ohm when hot but is a lot less until it gets hot. I do a lot of key-on events to download datalogs and fiddle with my tune. I think I will put another 50 Ohm resistor in the circuit just to make sure the current is never too high.
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Verdad Gallardo I am in a unique position where I have access to almost any engineer at Remy, and I have spoken with the engineer who has design control of this alternator. The L-terminal has a maximum rated current of 0.4 Amp. The recommended resistor to use with the L-terminal is 50 Ohm. There is nothing wrong with my resistor of choice. Root cause of problem is something else.
I did a little more sleuthing today with a Remy technical resource. We went down a few trails of thought and both landed on possible issue being rotor over-speed. The associated failure modes of the rotor and brush leads fit my symptoms pretty well.
Turns out the CS130D type alternator used in the F-body cars has a fairly low speed rating compared to other compact brush-type alternators (10K rpm continuous, 12K rpm intermittent). I don't know my exact pulley ratio but I can see it is in the ball park of 3:1. That means I am turning the alternator up to 21K rpm. So I'm thinking to myself, how does the alternator live on a LS7 Corvette? I found an easy answer to that.... it doesn't. Corvettes use a Valeo alternator. Even the aftermarket Remy part is a reman Valeo.
I think what I'm going to do is find an alternator with a higher speed rating and see how that rolls. I was told there are aftermarket companies that might upgrade the CS130D with stronger rotors. If so, that would be an easy drop-in replacement without the fuss of changing my FEAD.
I did a little more sleuthing today with a Remy technical resource. We went down a few trails of thought and both landed on possible issue being rotor over-speed. The associated failure modes of the rotor and brush leads fit my symptoms pretty well.
Turns out the CS130D type alternator used in the F-body cars has a fairly low speed rating compared to other compact brush-type alternators (10K rpm continuous, 12K rpm intermittent). I don't know my exact pulley ratio but I can see it is in the ball park of 3:1. That means I am turning the alternator up to 21K rpm. So I'm thinking to myself, how does the alternator live on a LS7 Corvette? I found an easy answer to that.... it doesn't. Corvettes use a Valeo alternator. Even the aftermarket Remy part is a reman Valeo.
I think what I'm going to do is find an alternator with a higher speed rating and see how that rolls. I was told there are aftermarket companies that might upgrade the CS130D with stronger rotors. If so, that would be an easy drop-in replacement without the fuss of changing my FEAD.
I have a 50 page thread about F body alternators. So far the only reliable cure is a used OEM truck alternator. A new OEM alternator would likely suffice. You me and everyone else has failure after failure with the parts store alternators and some even have repeat failures with the high end/high output pieces.
Click my user name and look at my posts, you'll find my alternator thread.
Click my user name and look at my posts, you'll find my alternator thread.
Seems that I solved the problem for now. This is an LS swapped car and I had the alternator L-terminal wired to a "Service Engine Soon" light bulb in the dash. It seems there was a poor (intermittent) connection of the electrical connector at the gage pod for the circuit that excites the alternator. It is the old GM green printed circuit board from the 1980's. I think this was causing the alternator to shut off sporatically.
I want to whip this once and for all and not have to worry about intermittent connections, or deal with the 50 Ohm in-line resistor that is needed for the L-terminal circuit. I moved the accessory wire from the L-terminal to the F-terminal and wired it directly to a switched 12V source (unused circuit I had left over from an add-on fuse center that I made for the LS swap). Dropped a 5A fuse in the circuit and alternator turned on, as it should.
For those that are wondering, the L-terminal requires an external resistor to keep current draw below max allowable specification. Whereas the I/F-terminal has adequate resistance internal to the alternator and can be wired directly to a 12V source.
I want to whip this once and for all and not have to worry about intermittent connections, or deal with the 50 Ohm in-line resistor that is needed for the L-terminal circuit. I moved the accessory wire from the L-terminal to the F-terminal and wired it directly to a switched 12V source (unused circuit I had left over from an add-on fuse center that I made for the LS swap). Dropped a 5A fuse in the circuit and alternator turned on, as it should.
For those that are wondering, the L-terminal requires an external resistor to keep current draw below max allowable specification. Whereas the I/F-terminal has adequate resistance internal to the alternator and can be wired directly to a 12V source.
Seems that I solved the problem for now. This is an LS swapped car and I had the alternator L-terminal wired to a "Service Engine Soon" light bulb in the dash. It seems there was a poor (intermittent) connection of the electrical connector at the gage pod for the circuit that excites the alternator. It is the old GM green printed circuit board from the 1980's. I think this was causing the alternator to shut off sporatically.
I want to whip this once and for all and not have to worry about intermittent connections, or deal with the 50 Ohm in-line resistor that is needed for the L-terminal circuit. I moved the accessory wire from the L-terminal to the F-terminal and wired it directly to a switched 12V source (unused circuit I had left over from an add-on fuse center that I made for the LS swap). Dropped a 5A fuse in the circuit and alternator turned on, as it should.
For those that are wondering, the L-terminal requires an external resistor to keep current draw below max allowable specification. Whereas the I/F-terminal has adequate resistance internal to the alternator and can be wired directly to a 12V source.
I want to whip this once and for all and not have to worry about intermittent connections, or deal with the 50 Ohm in-line resistor that is needed for the L-terminal circuit. I moved the accessory wire from the L-terminal to the F-terminal and wired it directly to a switched 12V source (unused circuit I had left over from an add-on fuse center that I made for the LS swap). Dropped a 5A fuse in the circuit and alternator turned on, as it should.
For those that are wondering, the L-terminal requires an external resistor to keep current draw below max allowable specification. Whereas the I/F-terminal has adequate resistance internal to the alternator and can be wired directly to a 12V source.
Teching In
Joined: Oct 2020
Posts: 8
Likes: 0
From: UK
would be great to hear back from you, I know it’s an old thread.
thanks!
found this thread whilst looking for answers on my 2 wire (but 4 pin connector) early type CTS-V alternator I’m using in a swapped ford Capri. All the diagrams i have seen say to use Pin ‘B’ (which is ‘L’ on my alternator) on a 12v switched ignition, but today whilst changing my oil, I noticed a high pitched electric ‘squealing’ noise coming from the alternator (car not running). I unplugged the connector and the noise goes away. I have a haltech elite 2500 that has a switched 12v source for the alternator and it also says to use Pin ‘B’. I think I’m going to try your way and Use the other pin, which is ‘F’ on the connector housing. I just wondered how you got on in the end, and what voltages were you seeing? Mine currently floats around 13.1-13.3 at idle and driving around. I also don’t fancy killing my new alternator!
would be great to hear back from you, I know it’s an old thread.
thanks!
would be great to hear back from you, I know it’s an old thread.
thanks!
https://ls1tech.com/forums/conversio...hrow-away.html
My information is for LS1 F-body alternator only. I'm not sure what the application guidelines are for other alternators like yours. I wouldn't move wires around unless you know for sure what you're doing.
Teching In
Joined: Oct 2020
Posts: 8
Likes: 0
From: UK
Might find some useful info in this link...
https://ls1tech.com/forums/conversio...hrow-away.html
https://ls1tech.com/forums/conversio...hrow-away.html
I am in a unique position where I have access to almost any engineer at Remy, and I have spoken with the engineer who has design control of this alternator. The L-terminal has a maximum rated current of 0.4 Amp. The recommended resistor to use with the L-terminal is 50 Ohm. There is nothing wrong with my resistor of choice. Root cause of problem is something else.
I did a little more sleuthing today with a Remy technical resource. We went down a few trails of thought and both landed on possible issue being rotor over-speed. The associated failure modes of the rotor and brush leads fit my symptoms pretty well.
Turns out the CS130D type alternator used in the F-body cars has a fairly low speed rating compared to other compact brush-type alternators (10K rpm continuous, 12K rpm intermittent). I don't know my exact pulley ratio but I can see it is in the ball park of 3:1. That means I am turning the alternator up to 21K rpm. So I'm thinking to myself, how does the alternator live on a LS7 Corvette? I found an easy answer to that.... it doesn't. Corvettes use a Valeo alternator. Even the aftermarket Remy part is a reman Valeo.
I think what I'm going to do is find an alternator with a higher speed rating and see how that rolls. I was told there are aftermarket companies that might upgrade the CS130D with stronger rotors. If so, that would be an easy drop-in replacement without the fuss of changing my FEAD.
I did a little more sleuthing today with a Remy technical resource. We went down a few trails of thought and both landed on possible issue being rotor over-speed. The associated failure modes of the rotor and brush leads fit my symptoms pretty well.
Turns out the CS130D type alternator used in the F-body cars has a fairly low speed rating compared to other compact brush-type alternators (10K rpm continuous, 12K rpm intermittent). I don't know my exact pulley ratio but I can see it is in the ball park of 3:1. That means I am turning the alternator up to 21K rpm. So I'm thinking to myself, how does the alternator live on a LS7 Corvette? I found an easy answer to that.... it doesn't. Corvettes use a Valeo alternator. Even the aftermarket Remy part is a reman Valeo.
I think what I'm going to do is find an alternator with a higher speed rating and see how that rolls. I was told there are aftermarket companies that might upgrade the CS130D with stronger rotors. If so, that would be an easy drop-in replacement without the fuss of changing my FEAD.
For what it's worth here, the original OE F body alternators had no problems being spun to 7k rpm or even more, with stock pulley's on the car or under drives (obviously) but after market replacement alternators (autozone variety) will die the first time you rev it to 6k with stock size pulleys, under drives may make these last longer. I killed multiple off the shelf rebuilds/new alternators the second I hit 6k rpm. The used truck alternator thread I created not only cured weak charging and crappy overall quality, but also allowed high rpm without failure. I hit 7k every day for months with the used truck alternator, so did the guy I sold the car to, and so did the guy he sold it to.
In other words. The original alternator would handle rpm, the junky replacements wont. So get an original or have one built if yours fails at rpm.