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  •  » parasitic drain

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    5/25/2013 9:34 PM  #1

    ps77sb
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    From: Crosby Texas
    Registered: 5/25/2013
    Posts: 22

    parasitic drain

    I HAVE A PARASITIC DRAIN ON A 1977 F100. I'M THE O/O OF THIS VEHICAL AND IT HAS 285000 MILES ON IT. THE ENGIN IS NOW A 351W/TL 4SP/3.50 T/L DIFF. I HAVE DISCONNECTED JUST ABOUT EVERYTHING UNDER THE HOOD. WHEN I PUT A TESTLIGHT ON BETWEEN THE POS BAT POLE AND THE POS CABLE THE LIGHT IS BRIGHT BUT QUICKLY DIMS. MY NEIGHBOUR SAYS THAT IT IS SOMETHING WITH A DIEODE. THE LAST THING I DISCONNECTED WAS THE PLUG FOR THE STEERING COLUMN BLINKER PLATE. WHEN I CHECKED WITH THE TEST LIGHT, THE LIGHT STAYED BRIGHT. IT DID NOT DIM AS WITH THE CHECKS. CAN ANYBODY HELP ME WITH THIS? THANKS PS77SB

     

    5/25/2013 9:46 PM  #2

    boomyal
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    From: Vancouver, Washington
    Registered: 4/01/2013
    Posts: 1,295

    Re: parasitic drain

    Be easier to read if it were not all CAPS!

     

    5/26/2013 7:18 AM  #3

    darren
    I FYI 24-7

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    From: Wentzville Mo.
    Registered: 4/05/2013
    Posts: 460

    Re: parasitic drain

    HEY!! Maybe thats BILLY WALTONS brother....
    To the OP: Have you changed anything recently with the truck? IE new stereo....

     

    5/26/2013 7:21 AM  #4

    darren
    I FYI 24-7

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    From: Wentzville Mo.
    Registered: 4/05/2013
    Posts: 460

    Re: parasitic drain

    A diode is an electrical "check valve" It shouldn't do what you are describing.
    A capacitor will hold a charge and then bleed off, but only after power is cut to it.
    Tell us some more about the problem. when you hook up the test light, are you switching the ignition on or off, or does the test light start bright then dim without touching the key?

    Last edited by darren (5/26/2013 7:23 AM)

     

    5/26/2013 8:40 AM  #5

    wsinsle
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    From: Belle Vernon, PA
    Registered: 4/01/2013
    Posts: 1,698

    Re: parasitic drain

    Darren's right with the capacitor, but I'm not convinced the problem I in the steering column. I would continue to disconnecting things (leaving steering column unplugged) until that test light goes out. Pull fuses, plugs even thing you my have disconnected before, the steering column issue may have given you a bad check. Find out what is keeping that test light on first. If it turns out to be a non issue then follow up on the steering column. Keep in mind as Darren stated, things such as new stereos have memory that put a small drain on a battery even when turned off, but this would not drain a car battery in. Fe days.

    If this forum can't fix it, it isn't broke.
     

    5/26/2013 9:12 AM  #6

    ps77sb
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    From: Crosby Texas
    Registered: 5/25/2013
    Posts: 22

    Re: parasitic drain

    I'm sorry I ment capacitor. The truck has sat for years and I tryed to get it on the road for the tomball bash. I got all of the lights working replaced the brakes and got REG/INSPEC stickers. I was good to go until the intake manifold blew out from years of bad antifreeze that friday night before the bash. The battery drain has been an issue for several years and I thought I'd live with for the B/D bash.
    All of the checks that I have done on this problem has been with igntion in the off postion. The radio was installed years ago. I unpluged the radio yesterday and the test light still came and then dimmed. The only time the test light stayed on with the ign off  is when I unplugged the S/C blinker plate. I pulled each fuse out with the ign off and the light would come on then dim. This is one of many things that needs to be fixed before I can use the truck as a D/D. thanks 

       •Thread Starter
     

    5/26/2013 9:26 AM  #7

    boomyal
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    From: Vancouver, Washington
    Registered: 4/01/2013
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    Re: parasitic drain

    Are you testing the amp draw or just the voltage?  Don't rule out the alternator.  I have had two of them where the diodes went bad.  The alternator continues to charge but drains the battery when everything is turned off.

    Last edited by boomyal (5/26/2013 9:31 AM)

     

    5/26/2013 9:47 AM  #8

    ps77sb
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    From: Crosby Texas
    Registered: 5/25/2013
    Posts: 22

    Re: parasitic drain

    I changed out the alternator a couple years ago thinking that would solve the problem.
    it didn't.  I didn't even check it out with a meter. I have a new meter that I talked to my neobhour that lives behind me that is an electrion and owns a 69 chevelle contvert and a blown 68 camero that he fixed up. He told me how to set up the meter. If I remember right the meter was on 10MA and it showed .088 on the readout. This reading is between the + post and the + cable with the ign off. Thanks

       •Thread Starter
     

    5/26/2013 10:21 AM  #9

    wsinsle
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    From: Belle Vernon, PA
    Registered: 4/01/2013
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    Re: parasitic drain

    If I am understanding you correctly that is about .000088 amp draw, less than 1/10 of a milliampe. How long does this take drain the battery? Are you sure when you unplug the radio there is not another wire going to the radio. Many digital radios ran a separate wire for memory not  through the main plug. You could set time or station on radio, unplug radio for a few seconds. Plug it back in, if time/station stays correct you did not disconnect the memory positive. I'm not saying this is your problem but it will help eliminate things.

    If this forum can't fix it, it isn't broke.
     

    5/26/2013 11:18 AM  #10

    ps77sb
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    From: Crosby Texas
    Registered: 5/25/2013
    Posts: 22

    Re: parasitic drain

    I pulled the plug out of the back of the radio. Their are 4 sterio jacks still pluged in the back of the radio. I just went to check what the draw was with the S/C blkr plate unpluged. The meter was set on DC10A to check amp flow. The readout showed 12+ and the meter was beeping I guess telling me it was overloaded. But while this was happening the headlights came on????

       •Thread Starter
     

    5/26/2013 12:29 PM  #11

    ps77sb
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    From: Crosby Texas
    Registered: 5/25/2013
    Posts: 22

    Re: parasitic drain

    I  rechecked this amp draw again. The H/Ls coming on was due to getting the radio out of the dash. I had to pull the H/L and wiper knob off to get the bezal off. Apparently the H/L switch was in the on postion from removing the knob. I reinstalled the knob turning the lights off. Retested with the test light and NO LIGHT.  Put the meter on it and no amp draw. Turned on park lights and it showed 3 amps. Turned lights off and turned ign switch on and it showed 4 amps. Turned ign switch off and checked amp draw again. Meter showed 0. So I guess all this time the H/L knob was not pushed in all the way? I'll have to put this all back togeather and recheck it. FYI I had replaced the H/L switch and dimer several years ago. I was coming home from a cruise and the all of the lights went out. After a few menutes of driving in the dark they came back on. I'll keep you posted if this comes back to haunt me. Thanks again for you replys

       •Thread Starter
     

    5/26/2013 9:18 PM  #12

    MS
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    From: Canyon Lake, Texas
    Registered: 1/24/2013
    Posts: 12,155

    Re: parasitic drain

    Have you tried removing the fuses one at a time until the light goes out?  That is a way to determine which circuit is at fault.

    Money you enjoy wasting is NOT wasted money... unless your wife finds out.
     

    5/27/2013 7:39 AM  #13

    BobE
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    From: White Plains, NY
    Registered: 4/04/2013
    Posts: 2,558

    Re: parasitic drain

    Did you install a capacitor (filter) associated w/the radio?  If so, try disconneting it, and any other capacitor that may be installed.  Perform the checks again and see what you get.
    If you're running a 'points' type distributor, don't worry about the filter with the points, it isn't energized unless the ignition in 'on'.
    Otherwise you can try to disconnect everything, then start to re-install, checking the draw for each connection.  Its long and tedious but should get to the root of the problem.
     

    65 Fastback, 351W, 5-speed, 4 wheel discs, 9" rear,  R&C Front End.
     

     

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