Alternator Wierdness...You Never Heard This one Before

[Viet Nam Vett]

Aternator Wierdness...You Never Heard This one Before

Ok ..I'll Make it short...1986 Vette ..CS130 Alternator
My chrome alternator took a dump after 7 years. Ordered a new chrome alternator from and internet supplier with a good rep.

1st one comes in ..big gash in chrome....send it back.

Install original Deco Remy Alternator from storage..Charging system ok no problems.

2nd one comes in...nice. Insall it.. and it runs 5 min ..gets red hot takes a dump. Return this one.

Install original Deco Remy Alternator from storage..Charging system ok no problems.


3rd one comes in.. install it ..run motor for 5 min..OK..it'works. Park Car.
Sunday get up..head to vette show...10 min into trip..no charge light comes on...takes a dump. Continue on to show..and as I drive Alternator wakes up and starts charging again. Voltage is all over the place.....14.1------13.2-----12.5------No Charge--back to 13.5 etc.


Get home remove Alternator
Install original Deco Remy Alternator from storage..Charging system ok no problems.

Call supplier and he says...Gee..never heard that one before. We have sold alot of these to 86 owners...

I explain...new optima battery fully charged..all connections tight. My old Delco works fine..What's up with yours?? He says...well we use slightly higher rated diodes then stock.

MAYBE YOUR POSITIVE WIRE ON THE BATTERY TERM OF THE ALTERNATOR TO THE BATTERY ISN'T THICK ENOUGH AND THE ALTERNTOR IS HEATING UP AND THEN GOING THERMAL AND SHUTING DOWN TILL IT COOLS AND THEN RESTARTING DUE TO THE THERMAL SENSOR IN THE REGULATOR.

WHY DON'T YOU TRY RUNNING AN EXTRA WIRE FROM THE ALTERNATOR TO THE BATTERY AND TRY THAT.

Have you guys ever heard of this BS??

If the battery is fully charged why would the alternator try and charge it in the first place..

Comments Please.

 

[G Winter]

a couple things come to mind. lose connection in the alt, a short in the alt. brushes bouncing. I don't know what yr that GM changed styles of alt. but on the old ones if the comontator was out of round or rough the brushes could bounce and stick away form it causing now charge condition . Being the original alt. works fine I would say the rest of your system is ok .
Unless you have some strange intermitent short in your system .

 

[Ken]

Let's see... I just went through an alternator change-out, and learned a few things I didn't know before.

Mine is an aftermarket alternator just as you have, only mine is a Powermaster XS Volt race alternator. According to Powermaster, high amp alternators are made by changing the power output curve and fine-tuning the pulley ratio. This involves changing the windings and the rotor coil. All of the changes in a high amp alternator increase the heat and load. In their alternators, a huge MOSFET transistor and heat sink ensure that the alternator can handle this increased load with capacity to spare.

So, I guess if your rebuilder "upgrades" your alternator with slightly higher rated diodes then stock, maybe this does cause it to run warm, making another, or larger, wire necessary.

 

[Viet Nam Vett]

Let's see... I just went through an alternator change-out, and learned a few things I didn't know before.

Mine is an aftermarket alternator just as you have, only mine is a Powermaster XS Volt race alternator. According to Powermaster, high amp alternators are made by changing the power output curve and fine-tuning the pulley ratio. This involves changing the windings and the rotor coil. All of the changes in a high amp alternator increase the heat and load. In their alternators, a huge MOSFET transistor and heat sink ensure that the alternator can handle this increased load with capacity to spare.

So, I guess if your rebuilder "upgrades" your alternator with slightly higher rated diodes then stock, maybe this does cause it to run warm, making another, or larger, wire necessary.

Point taken Ken..Thanks.

He told me he is using 70 Amp Diodes insted of the standard 35 amp type. But what I can't fathom is ...with a battery at full charge and no load other then the fuel injectors and ingnition to run..why does this sucker get so hot. I mean the case gets very hot. I can see why it goes thermal because of the heat.

The second one I had sent back that I thought was dead in fact was good when he tested it on his jig. I guess I didn't know that it had gone thermal and shut down. I don't know how he loads them or how long he runs them but on my car it works fine until it heats up and then drops out.

So...who knows where i can get a chrome 1986 Vette CS130? The stock diode assembly works fine.

 

[Ken]

I know this doesn't mean a thing, but that's one of the reasons I shy away from those chrome accessories. I dunno, I just don't trust 'em.

 

[Viet Nam Vett]

I know this doesn't mean a thing, but that's one of the reasons I shy away from those chrome accessories. I dunno, I just don't trust 'em.

Chrome is our friend......Chrome is good...Some chrome is bad ...and I need chrome ....

 

[Ken]

That's cool! :cool

 

[Moonunit 451]

Chrome is our friend......Chrome is good...Some chrome is bad ...and I need chrome ....

 

[c4cruiser]

You can always get the case from your stock alternator polished. As long as it gets reassembled properly it should work fine.

I would have had the chrome alternator tested at a local parts store before sending it back. He said it worked fine on his test equipment but you weren't there to see it. The fact that you had two of them croak and he said the second one is still OK per his test, raises a red flag to me.

The size of the power lead from the alternator is apparently fine for GM components so I can't see why this guy suggested that it was not large enough. With the engine running, the amount of power draw from the various systems (injectors, ignition, fuel pump, ECM, CCM, ABS and various relays) should be easily handled by a stock alternator.

How long did you leave your stock alternator in the car?? Just to check the charging system? Leave it in for a few days and see what happens.

 

[Viet Nam Vett]

It was on the car two weeks each time I waited for the new unit to come back.....No problems...

Good idea..Maybe I'll drop over and have them test this sucker..

 

[Viet Nam Vett]

It was on the car two weeks each time I waited for the new unit to come back.....No problems...

Good idea..Maybe I'll drop over and have them test this sucker..

Ok ...Had the Chrome Alternator tested. We ran if for about 10 min under load on there Altrnator test jig. It stayed at 13.5 Volts rock steady without any heat. It't didn' go thermal and shut down. stayed nice and cool.

I don't know how much of a load the jig put on it but the Bat terminal lead wire from the there jig was only about a 14-16 gauge wire.

The alternator was run in the correct direction as apposed to my mounting which is 180* making the unit run in reverse. So at this point I'm baffled????

The old chrome unit and the old stock Delco don't mind runnig backwards. So...experts take a shot at this one. What's wrong here...Bad ground on the new unit(Case to Mounting Point)..Bat Term Wire not large enough?

This is all the stuff talked about before...If this unit is heating up on my car I would tend to think that the Alternator Thinks it seeing a Large load that needs to be charged...But What????

 

[saxybill1]

The folks that sold you the alternator is absolutely correct. What he is suggesting should not just be for the positive wire from your alternator to the battery, you should also increase (match) the ground wire as well. This is a regular trick that most folks with quality stereo systems in their car will do as well. The supplied positive wire is just much too small to be able to take the power, installing a size 2 or 0 wire is the best thing to do; however, match it up with the ground wire as well.
Hope this helps.

 

[redc4corvette]

MSD makes the chrome alt in 2 different ampers I forget the first 2, up to 170 AMPS.
CHECK Power block tv site on 10-2 -04

 

[BigRed]

I JUST went through this BULLS%^T


Original died...replace it in the middle of no where with a junk rebuilder one

Died..

Had my supplier in town supply me a 140 Amp Chrome

It Would NOT charge at idle only at 2000 rpm Plus

WTH..

Send it to MY super duper rebuilder He laughs and says it is IMPOSSIBLE for an "old" style GM to produce 140 amps and the only way they can say it does is by running it at 3000 RPM with a double sized stater and a factory core which is why it USLESS at idle..So that might explain your funny charging.

So I gave him my Old junker rebuilder one (NEW style GM and not available to my knowledge in chrome) and gives me back a TRUE 120 amp.

Runs gorgeous...

This all happened within a 12 month period or I like to call it my charging saga...

Plus I ran custom ground wires direct to the frame and new powers and NOTHING I did affected the problem so your guy is full of BS, don't even go there if another alt is working. (trial and error is hard to argue with)

Ah yes and finally buddy told me that as we all know chrome retains heat like a bugger so that alternator goning to be cooking. And second ALL those people (that I know of) can't preload a bearing worth a crap (including mine) They set mine WAY to tight. I caught it (the back button was turning blue) so I dismantled it and set it properly.

Aparently Powermaster or one of them is making a high amp new style GM in chrome but Im sick of messing with it. Im just going to get a chrome shroud to cover a PEFECTLY working unit that doesn't NEED replacement LOL.

 

[Viet Nam Vett]

MSD makes the chrome alt in 2 different ampers I forget the first 2, up to 170 AMPS.
CHECK Power block tv site on 10-2 -04

Thanks...I'll check out MSD..

 

[Viet Nam Vett]

I JUST went through this BULLS%^T


Original died...replace it in the middle of no where with a junk rebuilder one

Died..

Had my supplier in town supply me a 140 Amp Chrome

It Would NOT charge at idle only at 2000 rpm Plus

WTH..

Send it to MY super duper rebuilder He laughs and says it is IMPOSSIBLE for an "old" style GM to produce 140 amps and the only way they can say it does is by running it at 3000 RPM with a double sized stater and a factory core which is why it USLESS at idle..So that might explain your funny charging.

So I gave him my Old junker rebuilder one (NEW style GM and not available to my knowledge in chrome) and gives me back a TRUE 120 amp.

Runs gorgeous...

This all happened within a 12 month period or I like to call it my charging saga...

Plus I ran custom ground wires direct to the frame and new powers and NOTHING I did affected the problem so your guy is full of BS, don't even go there if another alt is working. (trial and error is hard to argue with)

Ah yes and finally buddy told me that as we all know chrome retains heat like a bugger so that alternator goning to be cooking. And second ALL those people (that I know of) can't preload a bearing worth a crap (including mine) They set mine WAY to tight. I caught it (the back button was turning blue) so I dismantled it and set it properly.

Aparently Powermaster or one of them is making a high amp new style GM in chrome but Im sick of messing with it. Im just going to get a chrome shroud to cover a PEFECTLY working unit that doesn't NEED replacement LOL.

Thanks Big Red,

All I want is a stock freaken Chrome alternator...!!! Nothing more.. The stock 105 Amps works fine on my car. The problem is that the stock old style diode bridge is not available any more at least that I know of. So all these rebuilders use heavier bridges in there chrome units. My old chrome unit had the old style GM diode bridge and ran for approx..8 years..No problems..This new chrome unit's case also looks thinner then the Delco case and might not be as good dissapating heat. That's what's causing it to fail. It get red hot and the regulator shuts the unit down untill it cools...then turns it on again. The case gets hot as hell.

But I won't give up my Quest for a Chrome Alternator....Some one has to make a reliable unit..