I have a '73, 2.0, with FI that has a battery drain. Using my multimeter, I have a 57 mA drain at the battery. By removing fuses, I have isolated it to fuse #11 which supplies power to the interior light and the emergency flashers.
Fuse 11 has three wires converging to a single spade connector. When I separated the wires, I found that the smaller black/red wire accounts for about 53 mA of the current. That smaller wire is the power wire at the interior light - I confirmed the continuity with the multimeter. The drain is at that wire even if it is disconnected from the light switch. What now?
Does this wire go directly from the fuse to the light? I tried to read the circuit in my Haynes manual but it makes no sense. The diagram shows it going to the buzzer but I don't have a buzzer (at least I don't think I have a buzzer). If I have a buzzer, where the heck is it? The wires under the passenger seat are disconnected and there is no buzzer under there. The wires have been disconnected since I got it and the interior light has always worked and until now I did not have a power drain.
For now, I have disconnected the interior light so I don't drain my battery but I would like to have a working light.

Thanks.

Warrenoliver

If you have a console it goes to the clock in the console thru the connectors
buy the shift level under the rug.

I do have a console. I will have to pull the clock to see if it has the red/black wire on it also.
Does the wire go along the tunnel to the interior light?

Thanks.

Warrenoliver

Yes.

Nope, just checked. The wire to my clock is black with a blue stripe.

Warrenoliver

The black/blue and the black/red are connected on the interior light socket on
the back panel and then runs to the connectors for the console.

That's an easy check...

Pull the wire on the clock and see if it stops......

That's both the clock AND the drain.....

Other thought is to check to see if the connectors on the interior light are shorting out to the rear bukhead.

that's my thoughts!

When I pull the spade connector from the interior light, I still get the drain so it is not coming from the light assembly. There are two red/black wires on that spade connector. I will next try to disconnect the clock and try that.

Where does the red/black wire connect to the black/blue wire? Is that somewhere in the console or is it on top of the tunnel somewhere?

Thanks for the help so far.

Warrenoliver

If it is the clock...

Early VDO clocks use a solenoid to laod a spring that powers the movement. The power to the solenoid is controlled by a switch connected to the spring movement. The solenoid or switch may be bad and under electrical load all the time.

The solution is to replace with a new VDO or have a quarts movement installed in the old clock.

Every car has some current drain when parked. A level of .25 Amps is the highest acceptible drain. Anything higher will kill the battery quickly. Clocks, radios and EFI are the main causes.

My scematic also shows the Blue/black wire connected to the heater lever light after it leavs the clock. This should be the illumination wire. The Black wire to the clock is the power. This ties directly to the Red/black at the interior light. The red/black at the interior light goes directly to fuse 11. the other red/black at fuse 11 goes to the hazard warning switch terminal 30. The red wire on fuse 11 goes to the buzzer terminal 87a.

Hope this helps.

57ma ? That's not much at all, can't see that draining a battery very quickly LOL I would guess the interior light is 1 amp (1,000 ma) or so , someone chime in however it is a I think a live on all the time circuit and maybe something else has been added on by a previous owner.. I still don't think 57 ma is much to worry about, that's a small amount of current. If you have a battery problem maybe its something else..
Just my 2cents

I also have a continueous battery drain...

I know I have the old VDO clock, so now I will disconnect that and see if it stops killing the battery. I have my stereo independently wired, and it appears to be one source of power draw (not measured yet though). I wondered if I had the polarity reversed on my speakers....
Would that be a dead short even when the stereo is off?

I also had a cracked ignition module, that could "hop" the gap if the batt was fully charged, but not with just a couple of days sitting unused. Replacing that has helped starting power alot, but there is still a draw on the system, like yours.

Yes, that helps a lot! Thank you for the description. I still don't know where the drain is but I think I have it narrowed down to the clock.
The red wire that you traced to the buzzer terminal 87a has me confused. Where is that buzzer and or the terminal? I don't have a buzzer under my seat and I don't hear a buzzer when the doors are open.

Thanks for all your help.

Warrenoliver

The battery drain is very small I agree and seems to cause problems only after the car sits for 5-6 days. Remember, I am in Wisconsin and we have not had a very dry fall so the car sits in the garage for days (weeks) at a time. I am still driving it on dry days and will until the first snow falls and they salt the roads.
Drove it today and almost had to use the heater - 34 degrees

Looks like that was it!

My clock has never worked, but for some reason it began draining the battery. I have disconnected the clock and now my meter reads 4 mA drain.

Damn, schooled by a newbie!!!!

Thanks for all the help. You guys rock. Now I can put her to sleep for the winter without having to worry about a dead battery.


Warrenoliver

Damn, schooled by a newbie!!!!

I may be a newbie on this site...

Former Aircraft Electrician USMC
Former owner of a Car Stereo company
Controls electrician for over 20 years IBEW

...I know a thing or two about wires...

For those that don't believe... 500mA is a huge drain on the battery, every hour of every day, for a week...

Most NEW vehicles with all the new electronic gadgets only draw about 250mA. Any draw of 500mA or more over a week will kill your battery enough so that IT WILL NOT START.

So if an interior lihght only draws 1 amp, leave it on for two or three days and see what happens.

I you really wnat to help your charging system??? Ad additional ground straps and up size the charge wire from the alternator. This will allow more charge with less heat. Have ever seen cars with big stereos with the lights dimming at night? Factories only install wires that are barely adequate to operate the charging system. large wires cost more money.

I use the Jr. on the lawn tractor and the plus on the 914.......worth the $$.
http://batterytender.com/automotive.html