Alternator Regulator or Diode?
03-02-2003, 07:41 AM
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Alternator Regulator or Diode?
With new Alternator in place, battery trickle charged but no multimeter.
Headed over to RadioShack for yet another multimeter. Upon return: engine off - 11.97volts
engine at idle - 11.69 volts
lights & heater on - 11.57 volts
So the alt is not charging as advertised.
Am I correct in thinking that if a diode is fried I will have a no charge situation?
If I have a reduced charge situation is this a regulator problem?
TIA
John S. and Pattycakes <img border="0" alt="[crying]" title="" src="graemlins/crying.gif" /> <img border="0" alt="[ouch]" title="" src="graemlins/c.gif" /> <img border="0" alt="[cherrsagai]" title="" src="graemlins/drink.gif" />
Headed over to RadioShack for yet another multimeter. Upon return: engine off - 11.97volts
engine at idle - 11.69 volts
lights & heater on - 11.57 volts
So the alt is not charging as advertised.
Am I correct in thinking that if a diode is fried I will have a no charge situation?
If I have a reduced charge situation is this a regulator problem?
TIA
John S. and Pattycakes <img border="0" alt="[crying]" title="" src="graemlins/crying.gif" /> <img border="0" alt="[ouch]" title="" src="graemlins/c.gif" /> <img border="0" alt="[cherrsagai]" title="" src="graemlins/drink.gif" />
03-02-2003, 07:45 AM
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John, have you checked voltage at above idle speed? It should jump up a little I think.
Anthony Tate
79/928 Silver Metallic
Anthony Tate
79/928 Silver Metallic
03-02-2003, 08:24 AM
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John,
When I started my engine after the overhaul (Including the generator) the generator was not charging - It shoved up that was due to leak of internal magnetism in the generator - The fix was to run it relative high speed with load (test lamp)on terminal D+/O8 I.e. the test lamp to be connected to +12V -> terminal O8 (Instead of a test lamp you can use a normal 2-5W bulb)
When I started my engine after the overhaul (Including the generator) the generator was not charging - It shoved up that was due to leak of internal magnetism in the generator - The fix was to run it relative high speed with load (test lamp)on terminal D+/O8 I.e. the test lamp to be connected to +12V -> terminal O8 (Instead of a test lamp you can use a normal 2-5W bulb)
03-02-2003, 10:14 AM
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John, mine reads about the same as ours at the battery ternimals with a MM. Once reved above 3500 ROM, she jumps to ~13.5. The warnin glight on my dash-mounted voltmeter is on all the time, but it still charges fine. If I don't disconnect the battery she will drain the battery in a few days.....
03-02-2003, 10:47 AM
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An alternator converts rotary energy into electrical energy by moving a magnetic field (the armature) thru the coils in the housing. The magnetic field MUST be present for the alternator to generate electricity. It is initially created by the excitation current that is supplied thru the charging warning light and the parallel resistor. If the excitation current is too weak (bad resistor, bad bulb, bad connection), but present, the alternator will start charging ONLY at higher RPM levels. If the excitation current is not present at all, the alternator will never charge.
Once the alternator starts charging, it supplies its own field current. Since there is now voltage on both sides of the light/resistor combo, the light goes off. Once the alternator starts charging, the light/resistor combo has no effect.
If the charging warning light is on, there is voltage on one side of the bulb and not the other, and there is a problem, usually in the alternator.
The alternator coils produce AC voltage, which is not useful for our purposes. The alternator includes six charging diodes (one-way check valves for electricity) that convert the AC voltage to slightly-pulsing DC voltage. If one diode is failed open, the charging amperage will be reduced. If one diode is failed shorted, there will be AC ripple in the output voltage, and you will get whine in the radio. As more diodes fail, the conditions will worsen.
We sell rebuilt alternators, and will be happy to sell you one - but that might not be the best way to handle the problem.
My suggestion is that you find a good local auto electric shop - not a general repair garage, not an auto parts store. This shop will probably do nothing except for repairing auto electrics - starters, generators, alternators, motors. They can repair/rebuild your alternator, starter and motors, often at a lower cost than buying a rebuilt. An advantage - you get YOUR alternator back. If you still have the correct alternator on your car, you will still have the proper housing, the cooling cowl will still fit, etc.
Once the alternator starts charging, it supplies its own field current. Since there is now voltage on both sides of the light/resistor combo, the light goes off. Once the alternator starts charging, the light/resistor combo has no effect.
If the charging warning light is on, there is voltage on one side of the bulb and not the other, and there is a problem, usually in the alternator.
The alternator coils produce AC voltage, which is not useful for our purposes. The alternator includes six charging diodes (one-way check valves for electricity) that convert the AC voltage to slightly-pulsing DC voltage. If one diode is failed open, the charging amperage will be reduced. If one diode is failed shorted, there will be AC ripple in the output voltage, and you will get whine in the radio. As more diodes fail, the conditions will worsen.
We sell rebuilt alternators, and will be happy to sell you one - but that might not be the best way to handle the problem.
My suggestion is that you find a good local auto electric shop - not a general repair garage, not an auto parts store. This shop will probably do nothing except for repairing auto electrics - starters, generators, alternators, motors. They can repair/rebuild your alternator, starter and motors, often at a lower cost than buying a rebuilt. An advantage - you get YOUR alternator back. If you still have the correct alternator on your car, you will still have the proper housing, the cooling cowl will still fit, etc.
03-02-2003, 11:16 AM
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</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by WallyP:
<strong>An alternator converts rotary energy into electrical energy by moving a magnetic field (the armature) thru the coils in the housing. The magnetic field MUST be present for the alternator to generate electricity. It is initially created by the excitation current that is supplied thru the charging warning light and the parallel resistor. </strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Bravo Wally!
<strong>An alternator converts rotary energy into electrical energy by moving a magnetic field (the armature) thru the coils in the housing. The magnetic field MUST be present for the alternator to generate electricity. It is initially created by the excitation current that is supplied thru the charging warning light and the parallel resistor. </strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Bravo Wally!
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03-02-2003, 02:18 PM
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Wally, Erik, Norm, Anthony, KB, thanks.
Dennis suggested a different resistor in my earlier post recommending a (have to look it up) 60 or 80 ohm/5 watt when we go to a rebuilt or new alt. I implicitly trust Dennis but I always consider feedback/advice.
Would this have any affect on output.
As to the rpm/charge cycle taking my readings off of the pod ammeter -no difference- will try having someone rev her up and will use multi meter this afternoon .
ALL.
However, I think considering road speed VS rpm that I'd have to tag along with Anthony.
At 3000 rpm in 2nd I'm doing a little over 60mph.
2000 rpm in 3rd is a little over 60 mph.
I would think (not necessarily right)that the charging cycle would kick in at say 1100 to 1500 rpm. My idle is around 625 -650 rpm when settled.
KB,
I agree with Wally. Wether our problem is similar or not something else is amiss. I think it goes beyond the so-called 'typical' batt. rundown associated with the sHARKs.
I have had that run down battery problem for a long time irregardless of rpm, duration of run, lights on or off...something is wrong and it is probably simple... keep looking
TIA
OT anyone ever wiggle the Pan off a F-150,302 CI, EFI without dropping the exhaust?
Nut's won't loosen with multiple penetrating oil baths, propane heated or not. Please don't break today!
John S. & Pattycakes
Dennis suggested a different resistor in my earlier post recommending a (have to look it up) 60 or 80 ohm/5 watt when we go to a rebuilt or new alt. I implicitly trust Dennis but I always consider feedback/advice.
Would this have any affect on output.
As to the rpm/charge cycle taking my readings off of the pod ammeter -no difference- will try having someone rev her up and will use multi meter this afternoon .
ALL.
However, I think considering road speed VS rpm that I'd have to tag along with Anthony.
At 3000 rpm in 2nd I'm doing a little over 60mph.
2000 rpm in 3rd is a little over 60 mph.
I would think (not necessarily right)that the charging cycle would kick in at say 1100 to 1500 rpm. My idle is around 625 -650 rpm when settled.
KB,
I agree with Wally. Wether our problem is similar or not something else is amiss. I think it goes beyond the so-called 'typical' batt. rundown associated with the sHARKs.
I have had that run down battery problem for a long time irregardless of rpm, duration of run, lights on or off...something is wrong and it is probably simple... keep looking
TIA
OT anyone ever wiggle the Pan off a F-150,302 CI, EFI without dropping the exhaust?
Nut's won't loosen with multiple penetrating oil baths, propane heated or not. Please don't break today!
John S. & Pattycakes
03-02-2003, 02:56 PM
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</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by John Struthers:
<strong>Dennis suggested a different resistor in my earlier post recommending a (have to look it up) 60 or 80 ohm/5 watt when we go to a rebuilt or new alt.
Would this have any affect on output.
</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">John,
As I said, the test lamp (or bulb) on terminal 08 do the same as the resistor - In my case it was only a question of starting-up the generator
And that's is easy to try.
<strong>Dennis suggested a different resistor in my earlier post recommending a (have to look it up) 60 or 80 ohm/5 watt when we go to a rebuilt or new alt.
Would this have any affect on output.
</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">John,
As I said, the test lamp (or bulb) on terminal 08 do the same as the resistor - In my case it was only a question of starting-up the generator
And that's is easy to try.
03-02-2003, 03:01 PM
#10
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Erik,
Have to get the truck 's oil pump changed ASAP, but will try the jumpered/lightbulb resistor check immediately afterwards.
Thanks again
John S.
Have to get the truck 's oil pump changed ASAP, but will try the jumpered/lightbulb resistor check immediately afterwards.
Thanks again
John S.
03-02-2003, 03:20 PM
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It actually didn't start draining the battery until I got down there messing with the alt wires while I was putting in a new oil pressure sender. I'm some new wiring would help and maybe even solve the problem. I've also been doing the electrical PM on the ground points as time allows. That cured my possessed speedo.
03-02-2003, 05:53 PM
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Fact: The resistor/bulb excitation circuit is to START the field in the armature - period, end of story.
Fact: Once the alternator starts generating, the field is controlled by the regulator, which is fed by the generated current, and the resistor/bulb circuit DOES NOT control the amount of charging or the voltage.
Fact: If the charge warning light is on with the engine running, there is a problem.
Fact: If the voltage is not higher than battery voltage at anything over idle speed, there is a problem.
Fact: If the battery will not start the car after two weeks, there is a problem.
Fact: The voltmeter on the dash is an indicator, not a precision instrument. It can be made to be more precise, but you will need to do some cleaning and checking thruout the electrical system, and especially in the instrument pod.
Fact: Once the alternator starts generating, the field is controlled by the regulator, which is fed by the generated current, and the resistor/bulb circuit DOES NOT control the amount of charging or the voltage.
Fact: If the charge warning light is on with the engine running, there is a problem.
Fact: If the voltage is not higher than battery voltage at anything over idle speed, there is a problem.
Fact: If the battery will not start the car after two weeks, there is a problem.
Fact: The voltmeter on the dash is an indicator, not a precision instrument. It can be made to be more precise, but you will need to do some cleaning and checking thruout the electrical system, and especially in the instrument pod.
03-02-2003, 05:58 PM
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Watch the decimal point when purchasing a different resistor. I tried the resistor route before replacing my dead Paris/Rhone, and mistakenly put in a .45 instead of a 45 ohm! It charged allright, but the car would not shut off! <img border="0" alt="[ouch]" title="" src="graemlins/c.gif" /> 
03-03-2003, 12:11 AM
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Wally,
Touchy, touchy, touchy...?
Fact: The resistor/bulb exciter circut can 'GRAB'.
In effect, after prodding the alternator to start charging it forgets to let go. When you shut down - ignition off - the resistor is still in exciter mode which causes the Alternator to continue drawing juice. Hence, battery drain.
The purpose/intent of the exciter circuit is one thing. Theory and intent don't necessarily cover all the anomalies.
Fact: The exciter does not control voltage, current flow (recovery as added accessories are brought on line) FROM the ALTERNATOR. You are correct it is the Regulator. But if the exciter circuit is still active at shutdown the Alt. will continue to draw -voltage- down on the battery reserves until the car is run again resulting in a recharge, or, the battery needs a recharge, or, battery is totally drained. So the alt. draws a negligble amout of voltage - that does not result in a underhood fire- but it is drawing that voltage continuously in a controlled manner thru the resistor/exciter in a juice to ground mode.
Since the alt. pully isn't turning the Armature/field cannot generate electricity. So there is a circuit that runs from batt. to alt. that can -not supposed to-operate with the key in the off position simply because the exciter is ...
stuck ... for the lack of a better word.
Ding me if you want that's how I learn (sometimes).
I think we all have a piece of the right answer here. <img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />
I want to try Erik's idea -may have to remove or disconnect the pod resistor- to see if there is a change on the, admittidly, inaccurate dash gauge. Then again, if I disconnect the resistor/exciter I will have to use the multimeter on the Battery to see if that puppy is charging or draining with and without a load.
The other method would be to see if there is a drain on Batt. ( measured at Batt.). If a drain registers - ignition off - disconnect Alt./Batt. lead at Alt. and see if drain stops.
My replacement alternator is acting just like the old one so all I'm doing is some elimination work before I swap again -its a lifetime warranty- which will take about 2-3 working days to arrive anyhow.
I'll let you know with multimeter readings asap.
John S.
Touchy, touchy, touchy...?
Fact: The resistor/bulb exciter circut can 'GRAB'.
In effect, after prodding the alternator to start charging it forgets to let go. When you shut down - ignition off - the resistor is still in exciter mode which causes the Alternator to continue drawing juice. Hence, battery drain.
The purpose/intent of the exciter circuit is one thing. Theory and intent don't necessarily cover all the anomalies.
Fact: The exciter does not control voltage, current flow (recovery as added accessories are brought on line) FROM the ALTERNATOR. You are correct it is the Regulator. But if the exciter circuit is still active at shutdown the Alt. will continue to draw -voltage- down on the battery reserves until the car is run again resulting in a recharge, or, the battery needs a recharge, or, battery is totally drained. So the alt. draws a negligble amout of voltage - that does not result in a underhood fire- but it is drawing that voltage continuously in a controlled manner thru the resistor/exciter in a juice to ground mode.
Since the alt. pully isn't turning the Armature/field cannot generate electricity. So there is a circuit that runs from batt. to alt. that can -not supposed to-operate with the key in the off position simply because the exciter is ...
stuck ... for the lack of a better word.
Ding me if you want that's how I learn (sometimes).
I think we all have a piece of the right answer here. <img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />
I want to try Erik's idea -may have to remove or disconnect the pod resistor- to see if there is a change on the, admittidly, inaccurate dash gauge. Then again, if I disconnect the resistor/exciter I will have to use the multimeter on the Battery to see if that puppy is charging or draining with and without a load.
The other method would be to see if there is a drain on Batt. ( measured at Batt.). If a drain registers - ignition off - disconnect Alt./Batt. lead at Alt. and see if drain stops.
My replacement alternator is acting just like the old one so all I'm doing is some elimination work before I swap again -its a lifetime warranty- which will take about 2-3 working days to arrive anyhow.
I'll let you know with multimeter readings asap.
John S.
03-03-2003, 12:37 AM
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"Fact: The resistor/bulb exciter circut can 'GRAB'.In effect, after prodding the alternator to start charging it forgets to let go. When you shut down - ignition off - the resistor is still in exciter mode which causes the Alternator to continue drawing juice. Hence, battery drain. The purpose/intent of the exciter circuit is one thing. Theory and intent don't necessarily cover all the anomalies."
The only way that this can happen is with a bad ignition switch. The bulb/resistor circuit is powered from bus 15. There should be no power on this circuit when the switch is off.
"But if the exciter circuit is still active at shutdown the Alt. will continue to draw -voltage- down on the battery reserves until the car is run again resulting in a recharge, or, the battery needs a recharge, or, battery is totally drained. So the alt. draws a negligble amout of voltage - that does not result in a underhood fire- but it is drawing that voltage continuously in a controlled manner thru the resistor/exciter in a juice to ground mode."
Again - the only way that this can happen is if the ignition switch is bad and does not disconnect the exciter circuit. There is nothing in the exciter circuit or the alternator to "grab" or "turn loose" the exciter circuit.
The exciter circuit supplies battery power thru the ignition switch to "bootstrap" the field in the armature. Period.
The only way that this can happen is with a bad ignition switch. The bulb/resistor circuit is powered from bus 15. There should be no power on this circuit when the switch is off.
"But if the exciter circuit is still active at shutdown the Alt. will continue to draw -voltage- down on the battery reserves until the car is run again resulting in a recharge, or, the battery needs a recharge, or, battery is totally drained. So the alt. draws a negligble amout of voltage - that does not result in a underhood fire- but it is drawing that voltage continuously in a controlled manner thru the resistor/exciter in a juice to ground mode."
Again - the only way that this can happen is if the ignition switch is bad and does not disconnect the exciter circuit. There is nothing in the exciter circuit or the alternator to "grab" or "turn loose" the exciter circuit.
The exciter circuit supplies battery power thru the ignition switch to "bootstrap" the field in the armature. Period.
