HIGH OUTPUT alternator
http://www.billetalternator.com/corvette/
I purchased one (beautiful piece of workmanship), but my C5 electronic system rejected it, so I had to return it (damn). My biggest problem was getting "Charging System Fault" messages, etc. on the DIC. They claim that they are fully compatible, but I did not find that to be the case. You may have better luck than I did.
Also since I have an automatic, the C5 really wants a Decoupler, but all of their units are solid pulleys (not a problem on Manuals) - so I kept getting vibration every time I put the car in gear - drove me nuts.

The Best of Corvette for Corvette Enthusiasts
http://www.billetalternator.com/corvette/
I purchased one (beautiful piece of workmanship), but my C5 electronic system rejected it, so I had to return it (damn). My biggest problem was getting "Charging System Fault" messages, etc. on the DIC. They claim that they are fully compatible, but I did not find that to be the case. You may have better luck than I did.
Also since I have an automatic, the C5 really wants a Decoupler, but all of their units are solid pulleys (not a problem on Manuals) - so I kept getting vibration every time I put the car in gear - drove me nuts
Originally I tried several things to make the BT alternator work with the oem harness/pcm and it did cause some screwy issues. The alternator would not excite because the PCM was not sending it the start up charge signal, then it would get the charge fault code, however if you ran it to 2k rpms, the alternator would self excite and the charge fault code would clear. I ran it like that for a while before Mechman(BT) and I figured out the fix. They can even increase your voltage output based on the resistor they put in the jumper plug.
I pretty much always see 14.9-15.0v at the alternator, 14.5-14.6v at the battery and 14.0-14.1v on the DIC, that's with everything turned on and fully heat soaked.
Originally I tried several things to make the BT alternator work with the oem harness/pcm and it did cause some screwy issues. The alternator would not excite because the PCM was not sending it the start up charge signal, then it would get the charge fault code, however if you ran it to 2k rpms, the alternator would self excite and the charge fault code would clear. I ran it like that for a while before Mechman(BT) and I figured out the fix. They can even increase your voltage output based on the resistor they put in the jumper plug.
I pretty much always see 14.9-15.0v at the alternator, 14.5-14.6v at the battery and 14.0-14.1v on the DIC, that's with everything turned on and fully heat soaked.
Does BT sell the "jumper plug" if not who does? What does it look like? Part Number?
Which 12V source did you connect to? Where is that source? Color of wire, fuse, etc?
Who is THEY?
Thanks
Does BT sell the "jumper plug" if not who does? What does it look like? Part Number?
Which 12V source did you connect to? Where is that source? Color of wire, fuse, etc?
Who is THEY?
Thanks
Does BT sell the "jumper plug" if not who does? What does it look like? Part Number?
Which 12V source did you connect to? Where is that source? Color of wire, fuse, etc?
Who is THEY?
Thanks
Some cars don't have the issue.. Some throw the alternator on and it works like stock, some do not.. Year of the car doesn't seem to matter, although earlier years do seem to have the problem more frequently. Mind is an 02..
To the best of my understanding, here is what happens:
1) car starts, PCM receives a charge signal from the alternator (or lack of charge)
2) PCM sends a 12v charge signal to the alternator to excite the field and start charging.
3) BT alternator starts charging for a split second (like a voltage spike), sends it to the PCM, but the voltage is too high (PCM has a voltage target and timeframe).
4) PCM throws the Charge Fault code and discontinues to send the 12v excite signal to the alternator and it may or may not stop charging...(some do, some don't)
5) At 2000rpms, the BT alternator will self excite and start charging, regardless of the PCM's opinion, but you still get the fault code.
This ^^^ is the best of my understanding. I am QUITE sure someone will chime in and correct me.
The setup I have with the jumper wire is a work around, but it works. Only issue I have is if my alternator stopped charging, I would never get a charge fault code.. No biggie for me, I watch my gauges..
I'd rather have 14.0v at the battery at full electric load, at full heat soak with 3 fans, a stereo system, big fuel pump etc etc, then worry about a charge fault code or fuel efficiency from reduced alternator drag.
Last edited by ajrothm; Sep 10, 2015 at 06:39 PM.

this thread has become entertainment for me...
No Problems.... "slight vibration", but you get use to it... LOL
You have no means to insure correct output but keeping your eye on the gauge and not the road...remove the analytical algorithms that monitor the charging system ??? sure why not....
its a work around..????
When your Voltage regulator sticks and it fries your battery and electronics... it Not a problem... you get use to it.
Much like not replacing your oil pressure sender...
No, I wont respond to any of the insults or trivia... there are enough people in this forum over the last 15 years who have gone similar roots, I warned them... but they didn't listen. and they are back to square one...
I just want to thank those who have found the answer..." IM getting use to it...."
A little irreverent satire for the evening... I tried to help, but in reality, over the years, I am caring less and less about what path people want to take with their C5..
this thread has become entertainment for me...
No Problems.... "slight vibration", but you get use to it... LOL
You have no means to insure correct output but keeping your eye on the gauge and not the road...remove the analytical algorithms that monitor the charging system ??? sure why not....
its a work around..????
When your Voltage regulator sticks and it fries your battery and electronics... it Not a problem... you get use to it.
Much like not replacing your oil pressure sender...
No, I wont respond to any of the insults or trivia... there are enough people in this forum over the last 15 years who have gone similar roots, I warned them... but they didn't listen. and they are back to square one...
I just want to thank those who have found the answer..." IM getting use to it...."
A little irreverent satire for the evening... I tried to help, but in reality, over the years, I am caring less and less about what path people want to take with their C5..
I hope others don't feel this way. That way we can re-engineer where others failed with the C5.
By the way. I fixed the dim by listening to soft music instead of some 2pac.
A solid pulley makes perfect sense for a race car (and a manual shifter apparently) and it also is one less thing to worry about if you have to warrant an alternator (as I lost one stock alternator to the decoupler smoking). I don't race my C5, I just want to enjoy driving it... not fighting with it!
Even after speaking with their Tech Support on the issue after installing, they were steadfast that what I was experiencing was uncommon and that it had been tested in several C5s with no issues. All I know is that I did not need the hassle of being a beta-tester for that price.
I think they build a very solid unit, but the engineering stopped at the alternator and they never wanted to spend the time and money to make it fully compatible for the C5 as it would involve far more than a first-class armature and case - maybe even an entirely new custom regulator?
Evil-Twin's assessment at the time when I ran into this was correct. I still think someone "could" develop something like this for a C5, but I never found one that was reliable until I went back to stock (even that took 3 tries!)


















