Parasitic battery drain 66 300

Early C Bodies - The Slab Side Years

  1. Ralph Johnson

    Ralph Johnson New Member

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    I have tested for a parasitic drain by removing the fuses one by one an still have a reading of 1.69 on my multimeter. I do have aftermarket oil pressure and temp Gauge.

    Need help in next step to trace the drain Battery discharges after a couple days of sitting in garage. The car does not have a clock but does have the optional flasher switch and rear speaker
     
  2. CBODY67

    CBODY67 Old Man with a Hat

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    Nothing in that old electrical system which should have a parasitic drain. Check the diodes in the alternator. The clocks never did run down the battery, even THAT quickly. But the diodes in the alternator could fail.

    Just some thoughts,
    CBODY67
     
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  3. Davea Lux

    Davea Lux Old Man with a Hat FCBO Gold Member

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    Also check to see if the trunk light goes off after the lid is closed.

    Dave
     
  4. Turboomni

    Turboomni Old Man with a Hat

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    I have wondered about that on my refrigerator
     
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  5. SIPLOWGUY

    SIPLOWGUY Member

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    HA! I had one of those wonderful LG refrigerators sold by Sears as a "Kenmore Elite". The milk and food on the top shelf would spoil quickly. I kept blaming my Wife and Son for leaving the door open too long. Shortly afterwards the lens on the light warped like a potato chip. There was a "fix" because the light would stay on. Many fixes and repair attempts failed. I ultimately won my long fight with Sears and they replaced the refrigerator. The new one has an LED light. Sooo....the question is....how do we know if the light goes off in the refrigerator??? Premature spoiled milk may be one way lol!
     
  6. SIPLOWGUY

    SIPLOWGUY Member

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    BTW: After a being a longtime Sears appliance customer....I am done! Sears has totally gone to sh*t! Their Master Protection Agreement is worthless at this point. Their integrity has gone down the drain too. Sad but true.
     
  7. traintech55

    traintech55 Senior Member

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    Sears has slowly gone downhill since the 70's. Most of the stores in the Chicagoland area have closed. Trying to shop online with them is a joke. They are one company I will not be sorry to see go.
     
  8. Big_John

    Big_John Illegitimi non carborundum FCBO Gold Member

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    First, unless you've changed from the stock clock, the clock will only draw when it winds the main spring. It could be described as a short pulse of minimal power every couple of minutes.

    Question... .1.69 what? Amps? Volts? (doing a volt drop test)


    Since you pulled the fuses, that eliminates the trunk light, but I don't know about your Sears refrigerator.

    The draw must be in the section that isn't fused. Basically ignition, starting, head lights (just the head lights) and the charging system. Other areas could be the feed to the various accessories before the fuse block.

    First thing I would check is the charging system and it could very possibly be a bad diode in the alternator. Easy to check... Disconnect it and see.

    From there, you'll really have to figure out what's up with the circuits I listed. A FSM will help... Disconnect the feeds at the bulkhead connector if you get this far... My money is on the alternator.
     
  9. bnz84

    bnz84 Active Member

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    As I learn about power seats I understand they are always hot/powered. If you have them perhaps the switch is off center or corroded. Unplug to test I guess
     
  10. Big_John

    Big_John Illegitimi non carborundum FCBO Gold Member

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    That's correct, I forgot about those along with the convertible top, power windows and door locks. IIRC, all those circuits are on breakers rather than fuses.
     
  11. John Kirby

    John Kirby Active Member

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    Had a bad seat switch that drained the battery, you can tell by reaching underneath and feeling if the motor is warm. The power is supplied by a large red wire going to the motor assy. Another suggestion is to disconnect the alternator wire (the big one) and insert your meter in series with it. Put it in the 10 amp mode. There should be zero current if the alternator is ok. Use this method to check other possible unintended current draws. The windows, door locks, and seats are powered by a breaker (or two) behind the left kick panel.
     
  12. 1970FuryConv

    1970FuryConv Senior Member

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    I would pull the bulkhead connectors, one by one, take your amp draw reading, and then reconnect. These connectors are at the left side of the firewall in the engine compartment. If you pull a connector and your amperage draw goes away, use your ammeter on each wire on that connector between that wire and its corresponding socket at the bulkhead. When you find the wire that draws 1.69 amps, you've found your problem. Then it's a question of whether the wiring to the component is damaged or the component itself it shorted.

    If none of the bulkhead connectors are drawing amps (unlikely), you may have a short to ground in your engine compartment. This signals a boring process of removing tape and looking for damaged wire.
     
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