(1999 F350 diesel 7.3 single alternator system)Changed my alternator out and still not charging. Engine dies when pos. leads are taken off. Voltage to batteries is 12.2. Does not increase when instruments are turned on. Could it be the fuselinks? Where are the fuselinks?
You may have a bad plug wire to the back of the alternator you can test that with a light tester but when you replace a alternator in a diesel at start up it takes about 35 secands before the unit will kick on
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Not on new vehicles , you never ever pull a battery cable while it is running ! A voltage spike can take out electronic components ! That was 60's an maybe a few 70's vehicles ! That change when they started using transistors in voltage regulators an in engine modules. If it is show 14 volts it's charging ! I will send a link on how you test the charging system. How To Check Charging System EricTheCarGuy
First things first check whether the alternator is charging by starting the engine and whilst in neutral gear open the bonnet and remove negative terminal from your battery and leave the positive one in its place . If the vehicle stops then then the alternator is not charging but if it is still on then the alternator is very Ok.
But since the battery light is on as the car is on it means that the alternator has a problem . It is either the brushes are finished or the armature winding is bruised hence causing a short circuit .
if the battery light is on while running the charging system is not working.you can check with a volt meter,setting meter to dc volts & connect meter leads to battery.reading should be 13.2 - 14.5 volts if lower than this your only reading battery voltage.check single red wire to the alternator it should read battery volts 12v.if battery voltage is present than alternator is faulty,if no voltage reading you'll need to trace & repair the wiring note; battery should be fully charge before testing
u need to chek for batt volts at the pos pole on the bak of alt.should b batt voltage if not then wire from pos pole on back of alternator to battery could be broken,causing no output tobattery. wiggl voltage regulator wires while engine runs an check volts with a voltmeter to see if it jumps to over 13v wen wiggling connector.also chek fuses an fusible links for continuity.
Use a multi meter set to 20 volt dc range. Test the batery voltage by putting red lead on pos post and black lead lead on neg post. Record voltage. Now start car . The voltage should increase 2 to 2 1/2 volts above battery voltage. Now turn on all accessories in car . Voltage should stay at battery voltage or above. If it does the charging system is ok. If not the altenator is faulty or wiring is at fault.
Firstly is this a petrol or diesel if it's a diesel it's probably the alternator pulley failure due to collapsed bushes to check this u will need to remove the intercooler to check. If it's ok get hold of a multemeter and place the rd lead on the main pwr lead on the alternator and the black lead on the body of the alternator start the engine if u have battery voltage around 12 vthen the alternator isn't charging. U should see 14vto14.5v this check will work on the petrol
CHECK ALTERNATOR FUSE AND CHECK FOR DAMAGE WIRES GOING TO ALTERNATOR.NOW IF BATTERY CABLES ARE OLD THE POSITIVE CABLE MOSTLY CAUSE HIGH RESISTANCE IN CHARGING CIRCUIT CAUSING NO CHARGE CONDITIONS.MAKE DRIVE BELT IS NOT SLIPPING KEEPING ALTERNATOR FROM CHARGING.
If you have changed the alternator and regulator, about all that could be left would either be a short circuit that is draining current away, or a bad ignition warning light bulb. That is because the power to energize the field of the alternator, comes through this dash bulb.