Can an alternator electrically be destroyed by the engine?

[derjackistweg]

I own a really special problem!

My alternator is 10 years old and only 10t miles but dead. I could not believe tried some things but then decided to replace it with a new one. Also a refurbushed Leece Neville 165A 7701 afaik.

The new one worked. 500 km or 3 trips. Than it started to jump on voltage from 13,4 to 15,4 Volt within 2-3 times per second. Alternierend.
I have a digital voltage meter in the dash, so I know.

Batteries are new - of course.

Now the new alternator is dead. Again. After 2 months, 3 trips and 10 times running in total, less than 10h runtime!!!

So it could be an false alternator from the start... but I dont know. All of these are tested before sending. According to the letter in the box.

Van is a 93 7.3 IDI, N/A.

Afaik is this alternator pretty dump: It just reads the battery voltage and if lower it starts charging and never stops until the engine is shut off. It just varies the amount of charge by the running speed.
Thats it.

So question is:
Is there anything electrically that can prevent the alternator from working? Mechanicly there cannot be anything wrong.

Afaik there is no fuse or whatever.

 

[Austin86250]

I always have terrible luck with parts quality alternators are no different,
Make sure your yellow wire is clean and tight that’s what tells the regulator what to do so if it’s loose/ bad connection it will get readings all over the place

 

[derjackistweg]

I always have terrible luck with parts quality alternators are no different,
Make sure your yellow wire is clean and tight that’s what tells the regulator what to do so if it’s loose/ bad connection it will get readings all over the place

Hi,

yellow wire?

Which one? I know a yellow one at the GP relay.

This below is an older Photo.
Afaik there are just a negative wire (not seen here, connected to my engine), the big red one, the little red one witch got a new connector 2 years ago in this foto and the 90° connector which I have no clue where it is supposed to be connected. Afaik it never was.

Maybe the 90° cable tells the dash it is charging. I bought the truck with a alt. light on. But the alternator was always working till recently.

You must be registered for see images attach

 

[typ4]

Get rid of the leece neville. Old technology and PITA.
BTDT

 

[Clb]

GOOD SOLID AND CLEAN GROUNDS.
Ok that said , lets think...
Is the digital gauge guaranteed accurate and quality?
Are there any iffy connections?
We can blame Corporate Chimerica for ****** quality of manufacturing.
Did you do something like unhook or ground something out?
What changed?

 

[Black dawg]

that 2 pin connector is pretty rough....

 

[derjackistweg]

that 2 pin connector is pretty rough....

I think you mean the air conditioning one. That is unused, here in GER.

 

[derjackistweg]

GOOD SOLID AND CLEAN GROUNDS.
Ok that said , lets think...
Is the digital gauge guaranteed accurate and quality?
Are there any iffy connections?
We can blame Corporate Chimerica for ****** quality of manufacturing.
Did you do something like unhook or ground something out?
What changed?

Hi,

the digital one is accurate, I checked that. In winter, when the truck has not been running since weeks I had hard times with my bat. That was why. Since 2018 I have PV on my Van, charging the starting bat. Since that the problem is gone for 9 months/a, only when the sun is pretty low. So bats are alway very good charged to begin with.

Iffy connections (I actually dont know what "iffy" means but I can guess ) After a roughly 4500h in the build of this truck, you can assume that I checked all connections and rebuild them if needed. Not particualy all, but all that I know of.
The Frame ground is new. The engine ground looks good and is solid. afaik.

I did nothing to the truck that could be related besides that I do not start the engine anymore via switch to the starter motor but instead as it is supposed to be via the refixed starter relay (fender) and the key.

As far as I know these ALternators are dumb and start charging, when they "see" a running engine. They check the bat voltage and when running the alt. keeps charge.
On Euro 6 d engines the alternator can be disconnected electronically, when not needed. Afaik this is not possible with theses old tech.

 

[derjackistweg]

The fact that the charge went up-down-up-down in 1 sec, so like with 3Hz. From 13,5 to 15,2 looks like a false regulator for me.
OR like a false ground.

I would cut my arm of if it is a loose ground cable though.

Note that happened while running.

But the alt should not be loading above 14,4V anyway.
So this looks like a regulator prob. for me.

But 2 times in a row is strange - can be - but strange.

I can check the diode trio though. I did with a brand new one I got already. And this is according to the trouble shooting guide working correctly: 7 ohm in one direction on 3 poles and the other way around 40 ohms.

And I don´t care to change the 2 alt. BUT if anything causes the alt. to break - I want this to be fixed first.

 

[derjackistweg]

Get rid of the leece neville. Old technology and PITA.
BTDT

doesnt help course. For a different one I need a different alt stand/ conncetor. I cannot get that here in GER!

btw: I get rid of the complete Van in 2 months when the truck has an historic licence = 30 years. Needs to run of course.

 

[captain720]

I wouldn’t be surprised at all if two parts store alternators went bad, how about having the alternator bench tested by a local old school shop?

 

[typ4]

If you are getting rid of it then whats the worry, itl run a while on hot batteries. If you want to convert to ford alt I have pieces.

 

[derjackistweg]

If you are getting rid of it then whats the worry, itl run a while on hot batteries. If you want to convert to ford alt I have pieces.

Oregan to Germany? Not ideal for shipping +19% German Tax.

But thx

 

[derjackistweg]

It will take me probably 2h to change that is not the problem.

Also I can see immediately if the alt is broke or something else is wrong (probably not)


But can anything CAUSE IT TO BREAK? afaik not.

But if anything causes my alternators to break this is a 300$ repair each time!

 

[typ4]

Oregan to Germany? Not ideal for shipping +19% German Tax.

But thx

Yes, but sometimes necessary