Rebuilt Alternator lasted only 7 miles

Had my alternator rebuilt today. Drove seven miles and the battery sign comes on again and the voltage starts dropping to 10 volts.

Is there an aftermarket unit I can buy that works? The Ferrari alternator costs $1800. That sound too high to me.

Who sells the OEM alternator for a "realistic" price?

Are there specific rebuild kits or parts that I shoudl have the rebuilder use?

Edit: This is on a 2004 360 Spider.

Thanks,

Oliver

 

Which car??

 

Just carry it somewhere else to be rebuilt. I have had the alternators of my 328 and BB512i rebuilt before and they lasted for years and tens of thousands of miles...you just got a bad job...

 

2004 360

 

First talk to the place that rebuilt it. They should be willing to stand behind their work.

Also, if you haven't already, make sure that a connection hasn't come loose, or a wire gotten broken.

 

The person you took it to didnt rebuild it, they just fixed what they thought was wrong. Take it to a new place.

 

Why not have it fixed under warranty?
BT

 

If the car is no longer under warranty find an honest to god automotive electrical shop. There is no reason to pay $1800 for an alternator with a prancing horse on the box.

 

Don't stop trusting a rebuild. Just take it somewhere else.

 

Sometimes new brushes don't always seat against the armature properly. I have had one snap after a recent rebuild, I agree with comments above take it back and give them a chance to investigate.

My alternator guys, are great they fixed the malfunction right off for negligible charge, I think $7.....The overhaul was around $70 total.

More the hassle of getting it on and off the 308GTb but I'm improving with practice!

 

LOL that was my problem. After a bad rebuild, I figured I'd do it myself. Since I didn't know what I was doing, I had the thing on and off the car about 7 times. The first time took an hour but by the 7th it was 5 minutes. There IS a trick to it, at least in my car.

BTW My problem turned out to be those two screws that are insulated that hold the VR in were not replaced, and the 33 year old insulation was shorting it to ground. The symptom of this is the amp meter acting like a tach; not sure if your volt meter would do the same though if that's your problem.

Ken

 

An '04 Spider that is already out of warranty?! Congrats on the miles. Such cars are meant to be driven.

Sometimes the rebuild won't be up to par, true...but other times the problem will be getting the belt too tight upon re-installation (that burns up the bearings).

So was it the rebuild, or the re-installation?!

 

Not all rebuild shops use the same quality parts. Some places are sourcing brushes, rectifiers, diodes, etc. from countries that have questionable QA/QC, but hey, it's cheap. Shops that do rebuilds for marine or trucking still use the good stuff. If your shop can't make right, find another. Since you are in LA you should have many places to choose from.

 

What are you saying this time brother?? That he over-adjusted the alt belt too tight and its now causing the batt light to come again and the voltage to drop down to 10volts?? Dude,in this case...............it was the rebuild. But you are correct about over adjusting the belt and prematurely wearing the alt bearings. But not after seven miles one would think?

 

That's cool. I was asking, not telling.

Speaking of which, how do *you* tell if it was the rebuild or the installation (e.g. getting the belt too tight)?

 

Well,if they did a good rebuild........Example-Replaced both bearings,replaced the regulator,check the diode/rectifier packs,checked the rotor and stator,then done a bench/load test to see what it can do and see if it works. If they done that........id be happy. But......................i dont think they did do a good job with this one. It could be the install job if he has left the belt loose?? It may be slipping and the alt cannot charge the battery with a slipping/loose belt. And it would also put the batt light up on the dash. If he fitted a new belt,it may have strecthed as they do slightly and that may be the problem?? Belts dont always have to sqeal to be loose. So maybe its loose belt that needs adjusting?

 

Getting the alternator belt too loose would seem to jive with the symptoms described.

Getting the alternator belt too tight would eventually burn up the alternator.

A bad rebuild could also cause the above problems.

So perhaps the alternator belt tension should be checked **before** removing said alternator for another rebuild!

 

The tight belt would only put more load on the bearings causing the bearings to collapse,then that would cause the rotor to spin into the stator and damage the epxoy coating,which can cause it to short out and then totally stuff the alternator. But a quick check of the belt is a good idea before the alternator is removed again

 

we had a couple of those nippon denso units rebuilt and the have work PERFECT for over 5K km the oldest one and no problems!!

those are great units, have them repair it under warranty

 

Nippon Denso are very good alternators. Have never had any problems with them after being rebuilt either. But it also comes down to the guy doin the job i guess

 

if it was a delco unit it would be a diferent story!!!!!!!

 

They make good large paper weights or small boat anchors

 

or if wrapped around a blanket they make an incredible personal defense weapon

 

Now now. My Delco, albeit British made, alternator lasted 33 years. If I didn't fry the VR when I had to hot wire my car, it may have lasted another 33. The problem you guys have is the engine bays in your cars get too damn hot and heat kills these things. Poor Ferrari design? Or are the power requirements of your car too much for the alternator Ferrari supplies?

Ken