Low voltage and amp under load on alternator.

Discussion in 'Domestics' started by The old man, Jun 4, 2017.

  1. The old man

    The old man Hero Member

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    Please fill out the following to ask a question.

    MAKE: Lincoln
    MODEL Continental
    YEAR
    : 2002
    MILES: 275000
    ENGINE: 4-8
    DESCRIBE ISSUE....Replaced alternator on Lincoln. Have proven good battery, grounds were check out and are good, connections are good and cleaned. Everything check good except charging and amp rate under load. Under starting load with no ac etc. on, It charges 1375 volts which is low I know But more than that, the amp is only 10 amps at tops. Do I have to reprogram the pcm to recognize the new alternator to get it to charge with more amperage. By the way the alternator light never shows that it is not charging, but light is good and fuses are all good concerning the alternator.
     
  2. kev2

    kev2 wrench

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    I think the alternator is the issue - aftermarket?

    Attached is 2002 non PCM control and 2003 PCM controlled - check wiring against you set up...
     

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  3. The old man

    The old man Hero Member

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    It looks like mine is not pcm controlled according to your 2002 schematic which is what mine is. I don't have the 2003 wiring setup. I am replacing the rear air bags with springs this week because the right air bag had a big leak in it and the compressor for the air bags keep going on and off about every 10 minutes or so while going down the road. I shut the switch off in the truck because of the high amperage pull on the battery going down the road was too much on the alternator because of the low amp output of the"aftermarket" alternator. When I would go for a test drive, I started off with a battery in the 1240 volt or so and came back with voltage under around 1180 volts or so when airbag compressor switched on and coming on about every ten minutes or so. With the compressor off I have a voltage around 1230 volts when I come back, but amperage is only 5 or ten volts. I checked everything in wiring and fuses and ground etc and everything is good. I think it is the alternator also, but just wanted to check with you guys. Do I have to buy a motorcraft alternator in order for the alternator to work? Thanks for input Kev2.
     
  4. kev2

    kev2 wrench

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    FYI: they do make a conversion 'conventional' spring kit for these - eliminates the leak prone bags, pumps valves relays ... check the price.
    Your call - some are glad to swap others want that air ride...
     
  5. nickb2

    nickb2 Wrench. I help when I can

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    I have never heard of this in my life, with a PCM controlled alt or not. SO I would say NO to that. I have NEVER had to reprogram a PCM for ANY alt replacement regardless of make or model.

    But this industry is ever evolving, so that may be a thing in the future, but not for cars or trucks of this era.
     
  6. nickb2

    nickb2 Wrench. I help when I can

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    Second that big time, I have done a few of these conversion kits, the owners reported that the ride was still smooth, maybe not like the bags, but I sure never saw them back at the shop every other week.:) Thats a big bonus for the customer on a budget who likes this type of car, and also a better one on the tech who shytes his pants and rips what's left of hair out when he sees the same ride over and over again. Air bag rides for these types of cars need very high maintenance.

    If it was my car, I would rip out the stock air bag kit and go as Kev2 said.

    Much cheaper and more resilient. But that was only my $.02
     
  7. nickb2

    nickb2 Wrench. I help when I can

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    Again, to repeat myself, the only time I ever recommend replacing airbags, and o-ring kits, and snapped line etc is if you only absolutely need them for added loading issues. Even there, this car does not need that to function.

    Sometimes, replacing the whole mechanical system is often worth more than what car is worth at time of breakdown. In example, an 02 lincoln. Blue book is what? vs airbag replacement kit? As kev said, your call.

    It was just an option for lincoln to sell a more luxury/deluxe car. But there are always issues with the system as a whole as they get older. Costly modules and self leveling rod popping off all the time, and the list goes on.

    Ok, nuff said about that.
     
    Last edited: Jun 5, 2017
  8. nickb2

    nickb2 Wrench. I help when I can

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  9. nickb2

    nickb2 Wrench. I help when I can

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  10. The old man

    The old man Hero Member

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    That is what I am going to do is go with a "conventional" spring kit. Just trying to keep this car on the road for another year or so for By that time it will have over 300,000 miles and pretty rusted. Time for new car afte that.
     
  11. The old man

    The old man Hero Member

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    You are right nickb2, the car is not worth it. But trying to get it safely back on the road for another year till my son can afford a payment on another good car. I just got alternator problems with charging. Tried a junkyard alternator and it lasted about a day. Bought an ebay one and it charges a little but not enough to keep up with demands of this car. I got this last one and afraid that it will charge some like the other before it falters. I have not installed it yet. I have cleaned and check a lot of ground connections as far as battery connections etc, but really have not checked out the body grounds. I must have a high resistance somewhere and yet have not found where. Buying a new alternator belt to start with, but really don't think that is the problem. I have a known good battery in it and will have it tested just to be sure. I have installed a lot of alternators in my day and never ever had this problem. Alternator seems to be getting too hot from normal to me. If I had any more hair, I would pull it out and scream. Pissed off on this car and fed up.
    By the way the conversion kit for springs is coming in this week. This weekend I will have a good ride again Just have to find the alternator problem.
     
  12. NickD

    NickD wrench

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    One open main diode, six of them total will cause that very low output. Fools the voltage regulator, either that or a stator lead is loose, use to use brass nuts, but then soldered, don't ask me what year, seen so many alternators, my brains is like scrambled eggs.

    Air bags, not the kind that are in your steering wheel. Ha, an 89 Continental, Other vehicles had replaceable air bags, this one, dealer want over 600 bucks for a strut. Major problem is the bags would fold over the struts and stones would get stuck in there wearing a hole in the bag. This was my one and only Continental. Did keep it going for awhile with a tire repair patch kit.

    In my younger days, fell in love with the 1941, but never found one, had a V-12, but was able to buy a 37 Caddy for 75 bucks, really nice from Lake Forest, Illinois where all the super rich people lived. That had a V-16, but didn't keep it very long, high school peer pressure was too great, driving a funeral type of car. Did outgrow peer pressure, was a blast to drive that thing. Learned later that General Patten was killed in one of this, had a beautiful varnished piece of wood on the back of the front seats.
     
  13. nickb2

    nickb2 Wrench. I help when I can

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    Question, since this is a PCM controlled system, have tried pulling codes? Is check engine light on.

    Because this, as you say is not normal, and either you will have a charge light on in the dash as the PCM will do that and usually code. The PCM in these cars is smart enough to know when a system error is happening.

    But usually, this will show a message error in the instrument cluster on these cars. May have a BCM code. Check that out.

    I am just throwing ideas out here now.
     
  14. billr

    billr wrench Staff Member

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    Are we sure the PCM/BCM is controlling voltage? The schematic posted looks, to me, like this is simply an alt with internal VR.

    With several alts not working, I would be suspecting the belt tension; either the tensioner is bad or wrong belt is on there. Just a few mm of belt length can make a difference, and some aftermarket suppliers don't pay too much attention to that. They like to cover as many applications as possible with fewest belt variations.
     
  15. kev2

    kev2 wrench

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    My Bad - reading comprehension is not my best trait...

    How many alternators have you installed?
    Where did they come from?

    It seams you have the 02 set up, look at diagram attached and try to determine which connector.
    That will tell which alternator - check connector shape and wire color.


    PS- the no charging bulb is working...? On koeo?
     

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    Last edited: Jun 5, 2017

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