Electrical Issue

Hi Ron.
If you had a dead short there would be a blown fuse and this would not cause the battery to die.
You have a constant load that is causing the drainage.
How long does it take to drain the battery?
Your clock will use power but I don't have a problem with starting the car after 2-3wks.
Do you have access to a DC ammeter?I would use the ammeter and pull fuses until the load was removed.If you don't have a DC ammeter, I'm sure someone will chime in and tell you where the best place is to connect the test light to diagnose. I think the test light in series on either the pos OR neg will work. The test light will complete the circuit if you have a load. Once you pull the troubled circuit fuse, the light will go out.
Once you determine which fuse it is, you'll need that wiring diagram as you said.
Will

Ron,

You could also use the test light at the fuse panel. Just pull a fuse and connect the test light to the two clips that the fuse connects to. This will not check any unfused wires or equipment (like the alt, vr, ammeter, etc) that are between the fuses and the battery.

John

This Fuse Log is from the Large Repair Manual. It is accurate to the '74L. The Alternator Field is ON, All OF THE TIME, when the Battery is Connected! This will Not show up in your search as 'It' doesn't use a fuse!! Just hook up a 'Battery Disconnect Switch' to the ground cable, as I did. You'll never have a Dead Battery ever again! Come in the Garage in the Morning, turn ON the switch; a Fresh Battery Everytime!!

This is from the 'Red' owners manual for the '74'L, there is a slight difference between these two! Earlier Years? I don't Know! Happy 4th!

These Pics might help You too.

2

Ron you need a multimeter to test for a draw. First hook up the meter like the pic below. Key not in Ign. both doors close, windows down, cover off fuse block. Remove one fuse at a time. When you find the draw the meter will drop to 0. All power must pass through the meter.

I had this problem and the door pin was stuck and the red light in the door would stay on.

The ammeter must be in series with the neg. The diagram doesn't show that. One meter lead to the battery post and the other lead to the neg cable.
And yes, it must be a high current DC ammeter (~ 10amps). Most multimeters don't have this DC current capacity.
Ron, now may be a good time to make up your own fuse diagram. I'm sure it will be similar to a late car. Get the diagram from panteraplace.com and pull 1 fuse at a time (with key on) to compare it to the 74 schematic.
Will

quote:

Remove one fuse at a time. When you find the draw the meter will drop to 0.

This only works if the problem is on the load side of the fuse.

[QUOTE]The ammeter must be in series with the neg. The diagram doesn't show that. [QUOTE]

The diagram show a battery disconnect. Open the disconnect to test.

John

Here is a diagram of the Autolite charging system (mechanical relay) as found on the Pantera. Note that it is not Pantera specific, as the wire colors are different, but it is a good visual aid.

Note that voltage is available all of the time at the "A+" terminal of the voltage regulator and at one of the normally open contacts inside the regulator, but no voltage is present in any other part of the voltage regulator or the field of the alternator until the ignition switch is turned on.

John

quote:

Originally posted by MARLIN JACK:
...I Just Finished Telling All of You, WHERE the 'Draw' is!! I guess some guys, You have to 'Draw Them a Picture!' LOL...

That path to ground is protected by diodes. I had a fellow Pantera owner accidently hook his battery up reversed and it did great job of testing the diodes in forward bias. Lots of smoke and melted wires, diodes held the current load fine though!

I guess it would be possible to have a leaky diode that might draw a bit of current. On a Pantera that path is always there and not switched. The Pantera diagram is here http://www.panteraplace.com/page107.htm

My car can set for weeks and start right up.

Mike

quote:

Originally posted by MARLIN JACK:
...I Stand Corrected!! Thank-You!
But the Disconnect Switch is Still a Good Idea, and it is a Great 'Theft Deterrant'. With or Without a 'Fuel Shut-Off' Valve!
Carry-On!

Marlin

Yes, the disconnect is a good idea, especially with a valuable old car!!

Mike

You could simply have a bad battery, too. They sometimes develop a shorted cell, which will internally drain the energy from one (or more) cells. Sometimes they will seem to work OK after a jump start, but after you turn off the car, will not have enough power to start it again. Symptoms much like an electrical problem.
Rodney.

Thanks guys ..the ammeter sounds more like what I need. The meter I have is a Fluke T+PRO-1AC KIT Electrical Tester & AC Voltage Detector. I have not checked if it has a ammeter yet.

The battery was the first thing i changed.

I still need to find a the diagram for the larger fuse panel that came in a 1979 .. I'm thinking something like the rear defrost , the interior lights, the rear euro driving light, or some other silly optional electrical item is causing this issue.

Thanks All I will try to get to it tomorrow eve and let you know what I find.

Ron

Fix it ... it was either the dash lights knob was left ON or the other little knob was left turned to the postion where it clicks in the ON position ... not sure what the other knob does ..but un clicked it and the battery stays charged.

Thanks for the help

Ron

...well didnt quite fix it. Anyone know whats fuses 13 , 14 , 15 & 16 are for.

R

Here's the diagram from the owners manual for my '85 GT5-S. Hopefully it is similar to your 79...

Thanks you ... similiar it appears to be .. I decided to drop the car at a friends shop .. with the electrical issue we are going to get the factory ac working also with R-12.

Ron

Ron has your car got the one 16-way fuse panel?
Like this? 16-way
On mine fuses 11 to 14 are constant live.
Fuses 15 & 16 are for High Beams.

Charlie has 2 8-ways which I have not seen before.
So his top fuse panel, 8 & 7 correspond to my 15 & 16.
His top fuse panel 6, 5, 4 & 3 correspond to my 11, 12, 13 & 14.

Leaving either your illumination / control dimmer on should not effect battery drain with light switch off.
The same with the blower or icing switch, they should be live when the key is in accessory or run.
That is if the wiring is correct.
Let us know what you find out.

es mine has the 1 - 16 fuses ..but the 2 - 8 is helpful.

Thanks