I guess I need a new alternator?

[HAWAIIZR-1]

I thought it was my battery last month when my voltage just started dropping and the battery was dead when I barely made it home. Dash started flickering too. I bought a new battery and also charged up the Braille that went dead.

So I put the freshly charged battery back in and start it up with the laptop and Datamaster to find voltage at 11 volts and slowing dropping. Reving up the motor does not help to make the voltage go higher so I shut it down. I check the actual voltage on the battery and 12.88. Just for the heck of it I change to the new battery (Odessey 925) and it has good voltage too, but same thing when running it reads about 10 volts on the gauge and on the Datamaster and slowly drops.

So I guess the alternator is toast? It is a fairly new, rebuilt alternator that was replaced when I rebuilt the motor last year. I can't remember brand or where I got it from. I still have the old alternator and one of those rebuild kits that Scott Fabre talked about in his how to: http://www.zr1netregistry.com/Old_Proj/old_proj23.htm
The problem is all of that is in my 5 year storage before moving to Japan so it seems the easiest is to just replace the alternator.

How do I confirm this and any other suggestions? Any recommendations of a good alternator and what to stay away from? Maybe I don't want rebuilt and try to find new?

Thanks in advance. It is always something it seems.

Craig

[VetteMed]

Craig, some "rebuilt" units are nothing more than a cleaned up case, and whatever part had failed, replaced. That leaves you with a nice looking time bomb, waiting for the next 20 year old component to fail. So, if you're not sure of who rebuilt it or what they replaced, then you ought to either find a rebuilder to go through the unit again, or just buy one outright.

I bought a rebuilt from starterpros.com, and it seems to be serving me well as of now, they do offer lifetime warranty for a few extra bucks if I recall.... There's also some new units floating around out there, I think Jerry may have some Remy rebuilds too.

[HAWAIIZR-1]

Originally Posted by VetteMed

Craig, some "rebuilt" units are nothing more than a cleaned up case, and whatever part had failed, replaced. That leaves you with a nice looking time bomb, waiting for the next 20 year old component to fail. So, if you're not sure of who rebuilt it or what they replaced, then you ought to either find a rebuilder to go through the unit again, or just buy one outright.

I bought a rebuilt from starterpros.com, and it seems to be serving me well as of now, they do offer lifetime warranty for a few extra bucks if I recall.... There's also some new units floating around out there, I think Jerry may have some Remy rebuilds too.

Thanks Andrew. I must have bought one of those and nothing was wrong with my orginal alternator at the time and just put new one on since building the motor, but pretty sure if was rebuilt and like you said.

I'll check out starterpros.com and Jerry. Thanks again! Craig

[scottfab]

Craig, Too bad about the latest problem. Soon you'll have hit all the common issues and be on an easy streak. A couple things I'd recommend on a rebuild if you go that route. If possible take it to one of the parts stores that tests them free. Also spin the shaft and put your ear right on the body. Listen for a raspy sound. I should be smooth. If it's raspy there could be one of those bad rebuild bearings in it. I will not name the parts store name but one of them was selling these for years.

[A26B]

The Remy "plant" for the starters & alternators I stock, is actually right here in Edmond. In talking to the techs & engineers, I have learned a lot more than I knew before. There are several levels of rebuild, just as Scott described, ranging from only bearings & brushes to complete, meaning all electronics, rectifier, regulator, etc. Remy rebuilds to the customers spec for their particular rebuild brand ( I won't reveal those here). I got the impression that the major discount chains we are all familiar with, push their specific brand with what is essentially bearings, brushes, turned rotor & tested electronics. If the electronics test good, they are not replaced.

I carry only the fully rebuilt, including electronics, Remy label. Fully rebuilt is more expensive, but so is the hassle of doing the job over or being stranded.

[GOLDCYLON]

Originally Posted by VetteMed

Craig, some "rebuilt" units are nothing more than a cleaned up case, and whatever part had failed, replaced. That leaves you with a nice looking time bomb, waiting for the next 20 year old component to fail. So, if you're not sure of who rebuilt it or what they replaced, then you ought to either find a rebuilder to go through the unit again, or just buy one outright.

I bought a rebuilt from starterpros.com, and it seems to be serving me well as of now, they do offer lifetime warranty for a few extra bucks if I recall.... There's also some new units floating around out there, I think Jerry may have some Remy rebuilds too.

I agree with Andrew. Thats all they do replace the defective part, knock the dirt off of it and spray paint it silver and walla rebuilt alternator. As stated take it to a show you trust and get it done right. Or buy new

This being said I need to do the same thing with my bad unit sitting i na box in the garage.

[MikeGolf]

Originally Posted by scottfab

Craig, Too bad about the latest problem. Soon you'll have hit all the common issues and be on an easy streak. A couple things I'd recommend on a rebuild if you go that route. If possible take it to one of the parts stores that tests them free. Also spin the shaft and put your ear right on the body. Listen for a raspy sound. I should be smooth. If it's raspy there could be one of those bad rebuild bearings in it. I will not name the parts store name but one of them was selling these for years.

Great point. If it is still on the car you can use a mechanic's stethoscope to listen for the bad bearings. In the olden days we just used a screwdriver to our ear.

[HAWAIIZR-1]

Thanks for all the replies and advice. I don't know if they have a shop around here to repair or test and I'm sure it would be "Lost in Translation" here in Japan. I think I'm at the point to just buy a good quality rebuild and go from there. I can't think of what else it could be than the alternator on our cars for the symptoms, but will check what the FSM says too.

Thanks again,
Craig

[Hammer]

Hi Craig,

I use another foolproof method to determine if the alternator is charging or not. Place the the tip of a screwdriver at the back (if you can get to the back) of the alternator where the bearing is located. Keep it a little ways from the bearing area and move it slowly towards the area. If it is charging, the screwdriver will be sucked to the area by the magnetic field created. No suckie...no chargie. it won't tell you if the alternator is weak, just if it is working. So far this has been a failsafe way of telling if the alternator is bad or not.

Good Luck

[mike100]

Originally Posted by Hammer

Hi Craig,

I use another foolproof method to determine if the alternator is charging or not. Place the the tip of a screwdriver at the back (if you can get to the back) of the alternator where the bearing is located. Keep it a little ways from the bearing area and move it slowly towards the area. If it is charging, the screwdriver will be sucked to the area by the magnetic field created. No suckie...no chargie. it won't tell you if the alternator is weak, just if it is working. So far this has been a failsafe way of telling if the alternator is bad or not.

Good Luck

always learning something new. I'm gonna try that. I actually work on some 2 MW generators sometimes, but I never noticed the magnetism on the rare occasions that I'm near them while charged.