I just got my engine back in last week and immediately noticed that it hits 15.9 volts if I rev it up quickly but at normal throttle it maintains 13.4-13.8 volts. I replaced the voltage regulator today and it’s even WORSE. The old regulator contacts were ground down a good 3/16-1/4” compared to the new ones so I really thought I had it resolved. I checked all grounds and terminals and nothing was out of place. I guess the next step is getting it bench tested and if it’s a bad alternator I’ll see if FICMRepair will help me out since it’s out of warranty and I have done so much business with them. I’m not very happy with a $400 alternator with the best upgraded wiring and brand new batteries having issues in such a short time. Any other ideas before I progress?

 

Yeah, those holes on the contacts are at least 1/4” from the end on the new regulator. What the hell would cause them to wear down that much in just a couple of years? It’s not even a daily driver, I put about 10k on it a year.

 

Everything from Ed?

 

Yessir, everything but the replacement voltage regulator I swapped yesterday. Jack are those contacts a wear item? I wouldn’t think they would be...

 

The voltage issue is typically a voltage regulator failure. From the armchair, it might be prudent to get one of the Prestolite replacements, but even those today would probably be China-sourced.

They are a wear item but I don't have enough miles on my L-N to get up to you to compare. Typically quick wear out would be the contacts not being smooth or the carbon brushes not processed correctly. Or arcing at the brushes which you would see at the commutator, but they should not be conducting that high of a current. Are all the connections tight?

Please keep in mind I don't want to get into the middle of Ed's handling this.

 

This new regulator is the exact model the LN rep emailed me.
All positive and negative connections are tight, I even checked block and frame grounds last night. I have brand new mil-spec terminals on both batteries and both batteries are fully charged and less than 2 years old.
I don’t expect anyone to get in the middle of Ed and I. If he helps me out I’ll be happy but don’t feel like he’s obligated to. The alternator is well out of warranty but it seems like I’m not the only person that’s not completely satisfied with the poor duration of a high dollar USA made unit...

 

You did what I would have done. I didn't get far with an L-N rep, but any feedback from him?

Maybe I haven't been following, but I hadn't seen other failures.

My concern meter went up went I found out they are now owned out of China. And only parts of the alternator are made or assembled in the USA and I'm sure that over time will have a higher China content.

 

I haven’t gotten back to him, it was yesterday after work when I swapped regulators and found it did not solve anything. It’s weird, at highway speeds it puts out 13.3-13.8v but if I accellerate quickly it overcharges. I can slowly run it over 3k rpm and it won’t over charge. Nothing is different other than my new terminals. Same belt, wiring etc. I had zero issues before I pulled the engine.

 

 

I left him a voicemail, we shall see how this transpires.

 

Are you running the stock or smaller overdrive pulley? If the overdrive it might be prudent to move to the stock one. I ended up doing that as at the high of output the overdrive is not necessary.

 

I have had the overdrive pulley on it since I got it and never had an issue, always 14.1-14.3v. I don’t think it would all of a sudden be a problem after all this time. Razzi is bringing me an alternator to get me by this evening. Having a little FTE get together.

 

The other thing you could try is a new sense wire if you don't mind breaking into the OE harness.

The sense connection is the "control" for the regulator. It's what tells the regulator if more current is necessary to bring up the voltage. When I was trying to get L-N to understand that their regulator was set too high at 14.6v, they had the concern the sense was degraded downstream, telling the regulator the voltage was 14.3 when in fact it was 14.4 as a reference. Therefore the regulator increases current to get 14.5v.

That proved false, the regulator is set too high. Never the less, if there is something wrong with the sense wire circuit - the wire, the splice, the attachment at the connector, the regulator does not have the correct data. I tied the sense wire connection from all places, the pass batt, the drivers batt, and as GM does, a direct connection to the alternator output stud. They all stayed the same.

I deleted the other videos I set up privately to share with L-N, but I didn't get them all and I'll attach the one left. Anyway, something you could try is to take the patch connector that is provided in the L-N box if you still have it or buy a replacement connector. I would have the sense connected to the output stud so there's is no possibility of a resistance issue, and with a new connector, no possibility of wire damage down in the pin connection.

 

Interesting. I have a new engine and FICM harness so I really don’t want to go cutting into it unless the connector is truly bad. I’ll troubleshoot the alternator and cables first then if the problem persists I can start looking for issues further up the line. I guess I’ll test the plug at least but cutting into the harness will be the last resort.
I will know if it’s a wiring issue this evening when I swap alternators with the one Toreador has for me to hold me over.

 

You could do as I did, front or back probe the original connector to complete the circuit.