Runnning Car with Bad Alternator and VR "Shorted"

[JCCADILLACMOBILE]

My mechanic thinks my Alternator has become "Shorted" due to:

1) Being Wired WRONG,
2) Being Run with Belt LOOSE (Could spin Pulley with Two Fingers inside of Belt.. Ill get a new Belt, i see a small fray mark)
3) That it couldnt be tested at store, due to "European Configuration."

So, ill be purchasing a Warranted, tested Alternator .. NOT Remanufactured, just USED.. and have it Tested Again!

I simply want to confirm that:

1) My Voltage Regulator is INTERNAL to my Alternator on a 1985 Jaguar XJ6 4.2; and
2) That if my Alternator DID "Drop a Diode," That the Battery would discharge when left Stationery.

I also see TWO Small wires from my Alternator, not One.. Why is that? (One large wire, TWO Smaller wires.. !!!!!)

This is my Third post for the day, so i will watch the responses.. but EVERY TEST says:

1) GOOD BAttery
2) Drain Test = PASS (.o1A)
3) Charging - NO VOLTAGE.

I also CANT get the DASH bulb t light AT ALL.. But those Two wires are not connected at all, so maybe that is why. (Ill try to Ground it and see if it comes on.. but that doesnt make sense, as someone said that light gets is Power FROm tat small wire.) - Im wondering if it can XCharge with a "Non-Functioning" "Dashboard Battery Light" that Doesnt even come on when i turn the Key to Ignition, but no Starting.

Thanks for the input, the Alternator will be here in about a week or two.. - Joseph

Now i watch the Answers. until tiomorrow.

 

[willix]

So....No charge because they couldn't test it? Why didn't they just use a VOM and check the big cable terminal on the alt? This is confusing. If the alt has no output just R&R.

 

[eljefino]

You need that little light bulb, it signals the alt to work. Something about the bulb gets +12v on one side from the ignition key, then its other side wakes up the alternator. If the filament etc is bad in the bulb you have problems.

Many alts have 2 or more little wires for field control. Could be the second one is fusebox voltage level so if you get 1/10 volt drop in the wiring it ups the output to compensate.

You don't have to test voltage at the big lug either, it should be connected to the rest of the system, system voltage should be within a few 1/10s of 14v when running.

 

[BuickGN]

Originally Posted By: eljefino
You need that little light bulb, it signals the alt to work. Something about the bulb gets +12v on one side from the ignition key, then its other side wakes up the alternator. If the filament etc is bad in the bulb you have problems.

Many alts have 2 or more little wires for field control. Could be the second one is fusebox voltage level so if you get 1/10 volt drop in the wiring it ups the output to compensate.

You don't have to test voltage at the big lug either, it should be connected to the rest of the system, system voltage should be within a few 1/10s of 14v when running.


I was about the say the same about the light in the dash. My GN won't charge if the light is pulled or burned out.

 

[Win]

If you and your mechanic don't understand how the system works, how do you hope to fix it?

Why not make your life a whole lot easier and just get a factory wiring diagram applicable to your VIN number, remove all the bodges and hack jobs that have been done to your electrical system and are undoubtedly responsible for its non functioning status, and restore the system to its factory specification with the correct parts?

That's got to be cheaper than throwing parts at it, ad infinitum.