I think my Palladium remanufactured alternator needs to be remanfactured again. It's having trouble keeping the battery charged in my 1990 coupe even though I bought it in October 2007 and it has been used less than 5,000 miles. The battery is only 2.5 years old. The connections are clean. The car is driven mostly during the day. I don't run a lot of accessories. The radio/CD player don't get a lot of action. I don't drive it in the rain.

I won't buy the Palladium again. Some of the auto parts stores are running a disclaimer about the Palladium and saying it's very susceptible to bearing damage if the tensioner is not freewheeling. I didn't change the setting on the tensioner when I installed this alternator. The serpentine belt is firm but not overly tight. The previous alternator lasted three years and I can see why it died because it dealt with a lot of dead battery situations before I finally bought a battery charger and finally got the culprit replaced: a dying computer.

Is Power Master worth the money? Or is there another brand? Many of the alternators are 105 amps. Power Master is 140. Is there any real advantage in 140 amps? Thanks.

 

we had a ton of trouble with alternators on the 91, as in replacing the delco lifetime remans every year. the only thing that solved it so far has been changing to the 92's bigger one which required some creativity in the bracket department to get a rear support brace but it's been on there for 4 years now.

 

I bought a NEW lifetime warranty alt from Motor City Reman for $85. I have been running with the overdrive alt pulley on my March 3 piece under drive pulley set. So far so good and my driving habits sound a lot like yours. www.motorcityreman.com

 

measure your alt pully, they have 3 standard sizes with the smallest being a hair under 2" these alternators will fly apart if you spin rpm and use that little pully. 5400-5500 and the voltage spikes, then drops and your alternators life was shortened. move up pully sizes and you probably won't kill your alternator. the 92+ is a much better unit or you could buy a branded 160-200amp unit from ebay or elsewhere and use a really big pully, spin the hell out of the motor and not worry anymore. my L98 redlines at 6700 and the 80 buck underdrive set i found on ebay is the reason i have stopped killing alternators.

 

I don't know why you keep posting this. A 1990 stock or near stock motor hits the marshmallow at 4500 RPM and nothing happens to the alternator. Mine is fine after 2 years. If you are revving to 6700 it's not a L98 anymore. It is not helpful to post "on of" situations. I took off the original alternator on my 1989 at 52K and have it as a working spare. It is possible to tear up anything if you try hard enough.

 

do you race or track day very often? even a stock L98 is shifted at 5500, the stock power peak is around 4500 but that is anything but a shift point. the vast majority of the time too much rpm is what kills the l98 alternator. pully size has a big effect on this, take it for what you will, but the pully size someone uses depends on their motor and their driving habbits. you are right that even the small pully will work fine at 4500. if someone is a soft driver this would probably work great since you would have great amprage at idle. i actually have one of those 1.9" pullys that will work to roughly 5400rpm before the alternator goes south if someone needs it they can have it, just pay postage. also very easy to change with an impact gun.

 

I rest my case. Thank you very much. Exactly where in the OP's question did he talk about Track Day or racing his car. If you want to shift a stock L98 at 5500, go for it, but stay away from my stuff.

 

Funny you should mention high RPMs. It was only 10 minutes after I got the engine up to 4,000 RPM (maybe 4,500) that the battery light came on. A pickup truck was tailgating me. I came to a railroad track, crossed over it gently and then took off quickly to lose the truck.

I usually drive the car gently. When I bought the car over four years ago, the owner told me, "It's best to keep the RPM between 1,800 and 2,000." Maybe he knew something that I would find out the hard way.

I'm sure the alternator is shot. I checked the battery with two voltage meters today. Both said the battery had 12.41 volts with the engine off. With the engine running, the battery had 11.81 volts. Before I started the engine, my computerized battery charger said the battery had only a 70 percent charge. After running the engine for seven minutes, I turned off the engine and the battery's charge had dropped to a 60 percent charge.

I disconnected the negative cable from the battery and unplugged the alternator before hooking up the battery charger.

I'll check the pulley size. I plan on getting a new alternator at Advance Auto.

Thanks for the info.

 

Mine goes out so often I have a back up ready and can have it switched in less than five minutes including looking for tools. Is mine the same alternator if not is there a larger pully for it also ?

 

the pully that is so rpm dangerous is this one, the little 1.9" shiny guy. if you measure it straight as shown it should be a hair over 2" which of course equals a 1.9" diamater the belt actually sees. That big black sucker is on a 200amp alternator and measures 2.75" on the pully or just under 3" across. do not use the big 2.5" plus pullys and 105amp alternators, especially on automatics, the charging really suffers. http://item.express.ebay.com/CORVETT...mdZExpressItem this link is where i found my 200 amp unit and so far it seems much better than the auto parts store rebuilds. no issues yet. however it does come with that tiny pully that causes problems in the low 5s rpm wise. a 2.5" pully on that alternator would most likely be safe into the low 6s and still give good at idle charging. on the stock 105a unit a person can use a 2.25" pully without too much trouble and provided you aren't using the AC, headlights and stereo at idle for a long time. the worst part about all of this is the trippy voltage that your car experiences when you grenade these cheap alternators. i suspect the ABS issue i had in my recent post was tied to the previous owner poping alternators weekly using a 1.9" pully on a 6700rpm motor. as far as the first post, something just sounds odd, i have never seen one fail in that way. i supose the bearings could do that from too much rpm but a decently rebuilt should be able to take 5400 with no issues. maybe "decently rebuilt" is the keyword here.

 

This was very interesting.....This past weekend I installed a March 3 pc u/drive aluminum pulley set on my 1990 Vert. My previous setups in other projects with March pulleys was that the alternator pulley was larger in dia. The one with my set (from Corvette Central) was smaller. Did Not like this...left the original one on...the March pulley measured 1.662 dia. on top of the grooves vs. the 1.984 dia. on the OEM. I thought they had given me the wrong one but when I had to get a belt it seemed that this one was right. They recomended a 90-1/2" belt but had to settle for a 91" one to set the belt tensor at the "mean "setting.The crank pulley was smaller and the water pump pulley was larger which made sense.
What is March doing ?????? They could screw up a lot of alternators this way!!!!!!!!!!!!!

 

March knows what they are doing. This guy is posting this pulley BS all over the site. I have seen 3 or 4 threads where he says the same thing.
I have had my March 3 pulley set on for almost two years and no problem. I run my rpms up to 4300 - 4400 all the time. The slightly smaller pulley keeps my alternator output at the proper voltage.
YOU WILL NOT BURN UP YOUR ALTERNATOR UNDER NORMAL DRIVING CONDITIONS. You could discharge your battery in city driving conditions.
You would take the word of some guy you don't know and have never met, over a long time product manufacturer who deals with these issues every day! C'mon

 

Wow.....lol, i could have sworn i mentioned that the smaller pullys are fine in the low 5000 range. Also the quality of rebuild is strongly suspect here. Also, as far as march goes, they use to have underdrive pully kits with an overdrive alt pully that basically maintained stock charging etc..that sounds similar to what the forum member above was talking about. all these pullys do is manipulate rpm. that tiny pully on a stock crank shaft would spin the alt up real qucik and probably kill it, however, with the smaller wheel down under it should be fine. since you have both wheels, try the march kit as it came, see how it works, only move up size if you rpm fail the unit. maybe i'll say this a little more clear since at least one member has missed it the increase in pully size isn't usually needed until you move into an above stock RPM environment. i mean, i'm not trying to argue with you, march or anyone else. and hey, come on duck, can we stop the aggressive posts? we're supose to be helpful and friendly with each other ya know oh before i forget, back to the topic. i've had great experiences with powermaster, quality seems to be good. i think a lot of the forum alternator problems are honestly in crappy rebuilds with low quality parts, especially bearings.

 

I ordered and installed a "95" Vette CS144 140 amp alternator from Rockauto and never had a problem on my "91" L98.

All you have to do is trim the alternator case mounting tab a little and fab up another rear bracket support and that's it.

 

I'm leaving in a few minutes to return the Palladium alternator to Advance Auto. They're going to test it make sure it doesn't work. I'm not going to buy another rebuilt alternator. I'm going for a new one. I'm tired of taking the alternators out. Maybe I don't have all the fancy tools that a GM mechanic has, but the power steering reservoir is in the way of the lower bolt on the alternator and that alone takes 15 minutes to remove.

I'm going to replace the serpentine belt because it's got many hairline cracks in the "tread" part that goes into the pulley grooves.

Thanks guys for all the great information!

 

I bought a Beck/Arnley New Alternator today for $169. Was on sale at Advance Auto. Normally goes for $202. I don't know anything about BeckArnley other than the fact this Tennessee company has been in business since 1914, according to their website. I googled for complaints against Beck/Arnley alternators and found none.

If this one goes bad, I'm going for a Power Master.

The Advance Auto clerk/technician seemed to know something about cars. Even argued with me that a good alternator will put out 14 to 18 amps, even though my Corvette repair manual says 14 to 15. She said it's recommended that the alternator plug be replaced each time the alternator is replaced. A faulty plug could eventually damage an alternator, she said.

 

The O.P asked about the Powermaster 140 Amp alternator and I have experience with one. I bought the Corvette Alternator, 140 Amp, Powermaster, 1986-1991 from Ecklers for a little over $200.00. I had a new battery put in because my old one kicked the bucket. The Powermaster, properly installed by an ASE Master Mechanic, left me stranded on the side of the road in my almost stock 91 L98 vert.

A remanufactured AC Delco was installed the same day and I haven't had a single problem since - its been more than a year and a half. It charges at close to 18A and goes down to around 14amps at idle with the stereo, amplifier, and headlights on. From my single experience, if you buy the Powermaster, save the box. Oh, and Eckler's was very good about my return, considering how much I told them my flat bed tow cost!

 

Sorry to hear your new Power Master gave problems. I talked to a mechanic about my alternator and he said I should have bought an alternator from NAPA. I've been taking large jobs to this mechanic/auto repair shop owner for over 15 years. He said I should not buy electronic parts from Advance Auto. NAPA may cost more but it's worth it, he said.

 

Yes, it definitely sucked getting stuck on the side of the road (my first time). And NAPA has some quality parts, but some things, like my Fel-Pro transmission pan gasket was WAY cheaper at Advance Auto. Last weekend I put some NAPA rotors and new caliper pins on when I changed my front pads to Hawk HPS. FYI, the Hawk HPS are AWESOME and I used a micrometer to measure BOTH NAPA rotors before installing and they were within acceptable deviations.

I hope your new alternator is more reliable than past ones....

 

He's not posting BS - I grenaded the stock alt - it burnt up but not from spiking voltage - it was from the rpms of the alt that cause a chain reaction of destruction - the plastic fan elongated and tore up shorting out the internals then it burnt up

I had pics and a post up last fall

I went with a powermaster and zero issue to date