Parasitic drain...

68blackbird

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Battery goes dead after 2 days with it hooked up. Here is what I know... with light switch pulled 1/2 way, front/rear running lights come on. Pull light switch full out, headlights, tail lights come on, front running lights do not. With headlights on, brakes applied, the instrument lights dim a bit. Alt does put out 14.2 when car is running. Not sure where to start? Kel
 
Could be something staying on or a defective component in the electrical system. I would try disconnecting the Positive (+) battery cable and connecting a 12 volt test light between it and the (+) Positive terminal of the battery. Then make sure all lights and accessories are turned off and the doors are closed. If the test light is lit, even dimly, remove one fuse at a time from the fuse box until the light goes out. You may be able to find the drain this way, unless it's in a circuit that isn't fused.

I've had problems with a non-Mopar, where the transistor in the VR fails and allows the battery to drain through the alternator's field windings while the car is parked. The alternator and it's wiring harness were warm to the touch even though the engine hadn't been running. That may be something worth checking for. I'm not sure if Mopar charging systems can fail that way or not, but if they can, it would certainly show up as an amperage drain at the battery.

You may also be able to use a Multimeter set on "Amps" function for this test, but unless it can handle at least 20 amps you may fry it.

I hope this helps.
 
Could be something staying on or a defective component in the electrical system. I would try disconnecting the Positive (+) battery cable and connecting a 12 volt test light between it and the (+) Positive terminal of the battery. Then make sure all lights and accessories are turned off and the doors are closed. If the test light is lit, even dimly, remove one fuse at a time from the fuse box until the light goes out. You may be able to find the drain this way, unless it's in a circuit that isn't fused.

I've had problems with a non-Mopar, where the transistor in the VR fails and allows the battery to drain through the alternator's field windings while the car is parked. The alternator and it's wiring harness were warm to the touch even though the engine hadn't been running. That may be something worth checking for. I'm not sure if Mopar charging systems can fail that way or not, but if they can, it would certainly show up as an amperage drain at the battery.

You may also be able to use a Multimeter set on "Amps" function for this test, but unless it can handle at least 20 amps you may fry it.

I hope this helps.

10-4 will giv ethat a try. Battery is good, after a short trickle charge just enough to start it, I load tested it, ok. Not sure how that would affect the front parking/running light issue. Strange how the front running lights work with switch pulled 1/2 way, but they go out when switch is pulled all the way and headlights on? I'll try the fuse chase game, almost acts like the problem is in the light switch itself?
 
I believe the park lamps stayed on in the full on position only starting with the 69s. I know this is the way for 65.
 
I believe the park lamps stayed on in the full on position only starting with the 69s. I know this is the way for 65.

On my 300, the parking lamps are only turn signal indicators when the lights are on. They only illuminate full time when the switch is pulled half way out.
 
I think the dead battery and the dimmed dash lights aren't related. You circuit board in the dash cluster is the likely culprit for the dimming lights.

For the dead battery, my money is on your glove box light or trunk light staying illuminated.
 
I think the dead battery and the dimmed dash lights aren't related. You circuit board in the dash cluster is the likely culprit for the dimming lights.

For the dead battery, my money is on your glove box light or trunk light staying illuminated.


I checked trunk light, it's ok...didn't check glove light...hope that is it. Probably need to chase down a stupid ground somewhere
 
This happened to me once......I found out that the dimmer switch on the dash was turned to "ON" position and I didn't notice the map light was constantly on until it was too late. I'd shut the door and walk away. Not sure how yours is set up, but I'd start at the fuse box to find your constant power source.
 

A bad ground won't drain the battery,

Agreed, but as others stated, the battery drain and parking lights & and dimming issue may be? I do remember I could pull the light switch 1/2 way to have just front parking lights and tail lights, and have all lights when pulled all the way. Just weird front parking ligths go out with switch pulled all the way....I think I'd rather redo the lower ball joints than chase these gremlins....
 
Do your brights come on with the foot switch for your headlamps when the switch is pulled all the way out?
 
Do your brights come on with the foot switch for your headlamps when the switch is pulled all the way out?

Yes they do.


Brake pedal return spring? Brake lights might be staying on.

No sir, checked that. I checked all around, interior lights off, trunk light off, need to check glove box light when I get home.
 
Actually, the Park lights switching "Off" when the headlight switch is pulled all the way out is normal for a lot of cars and trucks built in the 1960's, so, that in itself is likely not a problem. My first car, a '63 Chevy did this, and my truck, a '69 Ford, also does this. The Park and Tail lights are lit with the switch half way out, but when the switch is pulled all of the way out, the Park lights go "Off" and the headlights turn "On". The Tail lights are lit in both switch positions. This is how a lot of them were wired back then.
 
Remember the dilemma Edith Bunker had in "All in the Family" with the fridge light staying on. She contended that every time she opened the fridge door, sure enough, the light was on. Whatever you do, don't lock yourself in the trunk. You can in fact be there for days with no light to jimmy the release catch.
 
I have heard of bad diodes in the alternator causing this problem. The alternator seems to be working OK, but you could check it pretty easy by disconnecting the field and power connections and seeing if the battery still drains.
 
Nobody knows how to isolate a ground using a test light an a FSM wiring diagram apparently.

Apparently...I did get out my test light, meter, and wiring diagrams, worked for 1 1/2 hours before posting here. Thought someone here may have some insight and direction, just finished dinner, heading back out there, I'll get it eventually...thanks for the advice...
 
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