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  1. #1
    fastback_Ry is offline
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    Angry Alternator not Charging

    My fellow 'Stangers I need some help! I've been dealing with this problem with my '65 Fastback, 289 for a few months now and it's gotten the best of me.

    This is where I'm sitting: replaced the alternator, battery, alternator wiring harness and voltage regulator. STILL my ALT light is on.

    Removed the alternator and it checked out good. Reinstalled it and
    verified the negative batt. cables and connections by measuring from the alternator case to the negative battery post. A reading higher than 0.25v indicates a problem with the negative batt. cable or connections to frame/chassis and enging block. I got 0.00v.

    I then checked the positive batt. cables and connections by measuring from the alternator output terminal to the positive batt. post. A reading higher than 0.35v indicates a problem with the positive batt. terminal to alternator or fuse block connections. I got 0.00v here as well.

    Now I'm not getting any reading...what the heck does that mean? Is that good or bad? I'd be happy with .05v. Give me some kind of reading. I've checked my connections over and over, sober and drunk, clothed and nude. I swear they are connected correctly.

    Going from post to post on the batt. it's lower than 13v.

    The only thing left to check is the voltage regulator and wires that connect to it. How do you do it and what am I looking for. Is there anything that I am over looking? Could it be a bad ground?

    I don't want to take the voltage regulator any where to get it checked out. Yesterday I had to show 2 guys at 2 different stores how to hook the alternator up to the test bench. Manny, Moe and Jack would have died ashamed and Auto Zone wasn't in the zone. NAPA didn't have test leads that went back to 1965.

    I'm at my end with this problem and may find it easier to throw some jumper cables in the trunk and call it fixed. Please, help a brother out.

  2. #2
    J is offline
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    So the battery is dead everytime you goto start it? Sometimes replacement parts can be faulty. Have you tried your battery on a different vehicle? I always try the simple shit first. Sounds like you have done everything perfectly.. must be bad stuff somewhere.


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  3. #3
    fastback_Ry is offline
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    No, the battery dies after say around 7 or so starts. One of my dads buddies said to check the cells by the Neg terminal. If the water is low then you have a bad ground. I still need to do that.

    I'll throw the batt in my truck and see what happens.

  4. #4
    gunner_501 is offline
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    J is on the right track with the bad parts .. I went through 4 voltage regulators on my 68 before I got one that worked .. I got mine at Pep Boys and on the last trip I told them if this one didn't work I was going to shove it where it didn't see day light .. LOL Just because it's new in the box doesn't mean it works .. Also another thought is to check the voltage regulator plug connection for corrosion .. it doesn't take much and a can of spray contact cleaner works wonders some times .. the last thought I have is check the ground on the block .. I painted an engine and forgot to clean that area off because I thought the bolt would do the job but it didn't .. I chased that baby for a week before someone pointed it out to me .. hope this helps a bit.

  5. #5
    HookandLadder is offline
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    Make sure you get a solid state regulator and not the old style. While you are at it, why not upgrade to a one wire alt and ditch all of the problems?
    Its Old.....Not Slow.

  6. #6
    Squid is offline
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    Quote Originally Posted by fastback_Ry
    This is where I'm sitting: replaced the alternator, battery, alternator wiring harness and voltage regulator. STILL my ALT light is on.
    Ok you have several questions here -- taking 'em one at a time.
    The alternator light in a '65 is fed from the voltage regulator. I don't have my manual here at work, but I'll make a note to check when I get home. Bottom line, if the v/r is not kicking in (stuck relay or dirty contacts) the light will stay on. I agree with another replier -- get a solid state (electronic) voltage regulator -- it'll save a lot of hassles.

    Removed the alternator and it checked out good. Reinstalled it and
    verified the negative batt. cables and connections by measuring from the alternator case to the negative battery post. A reading higher than 0.25v indicates a problem with the negative batt. cable or connections to frame/chassis and enging block. I got 0.00v.

    I then checked the positive batt. cables and connections by measuring from the alternator output terminal to the positive batt. post. A reading higher than 0.35v indicates a problem with the positive batt. terminal to alternator or fuse block connections. I got 0.00v here as well.

    Now I'm not getting any reading...what the heck does that mean? Is that good or bad? I'd be happy with .05v. Give me some kind of reading. I've checked my connections over and over, sober and drunk, clothed and nude. I swear they are connected correctly.
    Ok, what you want here is a very low reading ... ZERO is the best. You are checking the continuity (electrical condicitivty) of the wires. First you did your negative cable, grounds and connections. The more voltage that you have in that reading the more resistance you have in the route. Not a good thing. The same thing for the positive route. It should be 0.0v That is a good thing. Do the same tests while the car is running and let me know what you get.

    Going from post to post on the batt. it's lower than 13v.
    Is that with the car running? You should have about 13.8 with the car running, that means the alternator is charging. It will drop back down to around 12 when it's not.

    The only thing left to check is the voltage regulator and wires that connect to it. How do you do it and what am I looking for. Is there anything that I am over looking? Could it be a bad ground?
    Again, you'll need the manual which will have a test for the volt/reg. You can always pick one up, try that and if it doesn't work, return it. Cleaning the connections and looking for physical damage on the wiring is another option.

    Hope that any of this helps you out.
    - Jim

    sig by: Crimsonblack (Many thanks!)

  7. #7
    fastback_Ry is offline
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    All the readings that I posted were with the car running. Except I made one mistake. When the engine is running and I test the batt. terminals I'm getting over 15v. I took the voltage regulator in to get tested and the guy said it checked out good.

    Again, you'll need the manual which will have a test for the volt/reg. You can always pick one up, try that and if it doesn't work, return it. Cleaning the connections and looking for physical damage on the wiring is another option.
    What manual are you talking about?
    I've cleaned the connections and looked for damage on all exposed wires short of unwrapping the tapped portion.

    I have heard about the solid state volt reg (SSVR) many times now but to tell you the truth, right now I want to know why the light is on and how I can fix it. I want to fix this problem and after I do then I'll get a SSVR. That may sound stupid to some but I'll learn something in the long run.

    Update: Now when I tested the batt. terminals I am getting a little over 12V. I dont know what the deal is but I have been beat. I dont care what the problem is, I'm getting a SSVR!
    Last edited by fastback_Ry; 07-24-2008 at 03:33 PM.

  8. #8
    Squid is offline
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    When the engine is running and I test the batt. terminals I'm getting over 15v. Update: Now when I tested the batt. terminals I am getting a little over 12V. I dont know what the deal is but I have been beat. I dont care what the problem is, I'm getting a SSVR!
    The output of your alternator is fluxuating -- that is controlled by the voltage regulator. If your battery is low, there should be more current. The voltage should remain stable across all battery conditions.

    What manual are you talking about?
    I've cleaned the connections and looked for damage on all exposed wires short of unwrapping the tapped portion.
    The manual I'm referencing would be a Haynes or Chilton's manual for the car. I will check and see if my wiring diagrams (purchased on eBay for less than $10 cover a '65. If I remember correctly, there is not much difference, except when the '66 went to the amp guage instead of the light. The manual will specifically tell you how to test the regulator right there at the car.

    It just doesn't sound to me like it is anything else except that the voltage regulator is keeping the light on. Unless there was a short from another +12v line into the +12v line to the light. The chances of that happening are less than slim.

    All the readings that I posted were with the car running. Except I made one mistake. When the engine is running and I test the batt. terminals I'm getting over 15v. I took the voltage regulator in to get tested and the guy said it checked out good.
    Is your battery sealed? Altho slim, the battery could have a bad cell which could cause the high reading. Doubtful. You said that you replaced it. If it's not sealed, you could take hydrometer readings for each cell and see what the level of acid is.

    Another possibility is to put an ammeter in series with the alternator output (between the alternator and the solenoid) and see what the amperage is doing. If it is fluctuating when the engine rpm is stable, your v/r is shot.
    - Jim

    sig by: Crimsonblack (Many thanks!)

  9. #9
    fastback_Ry is offline
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    I got a Haynes and didn't see anything about testing the VR. Could have over looked it though. Still looking for a Chilton's. Seems like where one leaves off the other picks up.

    I took it to a place where all they do is rebuild alternators, starters, etc. Now the guy said he had a hard time getting it to kick on. He had to jump the batt. connector on the VR but when he did the VR kicked on. He said rev the engine while its running to see if the light clears. Which I had been doing with no results.

    A short going to the ALT light wouldn't be a long shot. Very well could be the problem. I've been pulling wire from under the dash that isn't even connected to anything...either end. It's stump-jumpin' wiring going on under that dash. Shoot, it could be a bad VR wiring harness.

    Im getting ready to head to Delaware for the weekend. I'll check around there to see if anyone has a VR. If so, I'll pick one up and hook it up when I get back. If that doesn't do the trick I'll keep on plugging away.

  10. #10
    fastback_Ry is offline
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    .
    Last edited by fastback_Ry; 07-30-2008 at 04:38 PM.

  11. #11
    Squid is offline
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    Did you get a v/r?
    - Jim

    sig by: Crimsonblack (Many thanks!)

  12. #12
    fastback_Ry is offline
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    Yea, I got a V/R. Put it in and now the friggin' car wont start. It turns over but wont fire. Man, this is like being on a merry go-round...except it aint merry.

  13. #13
    fastback_Ry is offline
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    Adjusted the float and got the car started. Put the new V/R in and for the first time in a year I dont have an ALT light starring at me in the face. Thanks for your help Squid. You helped me with the alternator problem a while back and the ALT light problem. Thanks for sticking with the post and helping me thru this. Big monkey off my back. Thanks agian, I really appreciate it.

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