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Alternator problems ??

Put your volt meter on the battery with the engine off and check your reading. Now start up the van and do the same. Your voltage should increase by 1-2 volts. 13.74- 14.50.
 
The problem started yesterday I went into a store and came out and it would not start dead battery got a jump driving home it quit. I charged the batterry for an hour started great the battery read 10.78 volts??? I went out there this morning the batt. is dead first things first Im going to get the battery checked (dead) free replacement Mills Fleet Farm batt. ps.it would not run without the batt.cable on...thanks for your help.
 
Never run and disconnect the battery cable.A faulty internal regulator can let the voltage run up high and destroy a lot of parts .This is a dumb stunt...
 
Good battery will read 12.6, engine off, 14.6, engine on-under full load (lights on, high speed fan, etc). Greg
 
running with cable off battery can cause voltage spike. ECM's don;t like these, can fry lot of electronics doing this.
 
If the charging system is working, the battery voltage should rise when running and as RPM increases. Just setting there NOT running battery voltage should be around 12.6 volts but if you start it the voltage should rise to at least 13 to 14.5 or so depending on the battery and charging system IFFFFFFFFFFFFFFF its working. Many parts houses will test BOTH a battery and charging system FREE OF CHARGE.

John T
 
I do not know about your 96 van, but on my 89 Dakota truck the voltage regulator is in the SMEC (Single Module Engine Controller) BOX. Get the MANUEL for your vehicle and check the charging system the way the Manuel says to.

Kent
 
I did something similar and my alternator went to 20+ volts and burnt out my headlights. To get home I had to drive at low rpm with every electrical load I could turn on running or my dash lights would go very, very bright.
 
Go to the battery kiosk at wallyworld. Buy the digital plug in voltmeter that fits the cigar lighter or power accesory socket. About $16. Check for the voltages John T says, though since this is in the midst of the wiring the voltage swings will be wider.

10.2 volts after charging looks like a shorted cell, which can also fry the alternator.

The charging voltage will be highest, as much as 14.8 volts, when everything is cold, I much prefer when its warm for that to be 14.200 volts maximum for best battery life.

Gerald J.
 
Hello plow hand,
You can check the generator output with a volt meter. IF battery voltage is 12.6V at 80 Degrees F. the charging voltage,with the engine running for a minute or two, should be 13.8 to 14.2 volts.The voltage you measure can be effected by loose connections, corroded connections, and low generator voltage output. Start at the battery and make sure ALL the connections are tight...............GOOD LUCK.
Guido.
 
Quick and dirty way of telling if your alt. is working is with the engine running take a screwdriver to the back of the alt.case where the bearing is , and see if the screwdriver is "attracted" to the bearing cap...if the alt. is working the rotor will have a feild and the magnetic pull will attract the screwdriver...no magnetic field , no charging.....Shawn
 
That just proves that the rotor is magnetized. But if it has bad diodes or grounded stator windings it still won't charge.
 
Most ALTERNATORS stop charging when the brushes get WORN to where they cannot make good connection with the slip rings on the rotor.This is the most common cause of trouble.This is the first thing to look at.You did not quote how many miles are on the unit.I know my answer has nothing to do with your question. CENTAUR
 
Gentlemen ,thanks for all your input I had the battery tested and I got a new one (free) test guy said there was something wrong with it.The van starts good now but shows it is not charging. I tapped on the alt.with a screw driver it shows a charge now so it would be safe to say it is the alt.????
 
Early Chrysler alternators had brushes that could get fouled with dirt and oil.They were easy to clean or replace without taking the alternator off the car.Have not worked on the new ones so cant say for sure.
 
Tractors and early cars with 3 brush generators can run up to 20 volts if the battery gets disconnected.There is always some joker who will say take off the battery cable and see if the engine keeps running.I had just bought a 36 Ford and was going along one night when the headlites got real bright and went out.I went into a parking lot and found a battery cable loose.Fixed that and found the tail light was out.Still had low beams and stepped on the brake light when some cars came up behind me.I also found out later that you should never switch on the lights right after the engine starts in cold weather on old cars.The cold battery does not load the generator right away and out go the lights.Ford tractors with lights will act the same way if they had a 3 brush generator.
 
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