C3-'71 Battery Drain

[Dennis M.]

I have a .25 amp current draw with the key off, and can't find the problem. I didn't notice any problem before I removed and replaced the clock. While I was doing the clock, I replaced all the instrument lamps in the guage cluster, and shift console.

Any suggestions on hunting down the problem?

[Stephen L.]

Re: C3-'71 Battery Drain

Pull the fuses to see if the "drain" goes away. If it does then reinsert them one at a time to see what circuit is the culprit. From there you need to see exactly what is on the circuit. If removing all the fuses doesn't clear the "drain" then you need to study the wiring diagram to see what else is connected thru another source of power. Was the clock working when you removed it? Is the .25 amp drain continous... or is it only when you connect the battery? Could it possibly be the clock spring solenoid?

[Dennis M.]

Re: C3-'71 Battery Drain

OK-Found the fuse that is the problem. It is the "clock-lighter-ctsy" fuse.

I hear the clock selenoid click, then the clock runs for a few minutes.

I'm suspicious of the clock, since it has a new movement.

Has anyone seen a clock draw 250 mA, after it winds?

It would take about 50 K Ohms to cause that draw, maybe a defective movement?

I hate to think that I have to get in there and pull the clock again.

[Stephen L.]

Re: C3-'71 Battery Drain

Dennis, The clock is mechanical with a spring that winds up to drive it. The spring is wound every few minutes by a point contact switch that energizes a coil that causes a mechanical movement that winds the spring. That is why the clock runs for a few minutes and then the "winding cycle" repeats. If the current draw is ONLY present when the clock winds (momentary draw) then everything is fine. This is exactly the way its designed. If you leave the fuse out for about 5 minutes and reinsert it, the clock will wind during which you'll see a current draw. It typically takes about 1 sec. Then the current draw will go away until the wind is required in about 2 minutes.
When you had the clock out it was probably repaired so that it would run. Correct????

[Dennis M.]

Re: C3-'71 Battery Drain

Steve--The clock movement was replaced, and appears to work. Except that is around 50 K of resistance on the line from the fuse, tested with the clock running, and the batt disconnected. When the clock runs down, the points are closed, putting the selenoid in the circuit, waiting for the batt to be connected, and initiate the wind cycle.

I emailed the clock repairman, and asked if he had ever seen this problem.

I'll have to tear the dash apart again, so I can reach up and pull the power connection from the clock. That will tell me if it is the clock, or something else bridged onto that line.

Dennis

[Dennis M.]

Re: C3-'71 Battery Drain

Steve--Thanks for your input.

I'm at a dead end here. The fuse that is labeled "clk-ctsy-lighter" is the circuit that has the problem.

I have disconnected the clock, lighter, and with courtesy lights off, still have the problem. I have examined the wires as best as possible, and don't see any thing obvious. I'm going to qive up, and rely on the batt disconnect switch to keep me from running down the battery.

I've found that sometimes more problems can be created by tearing into these things, instead of leaving them alone. Getting into the guage cluster, and shift console is a bear, and I'm going to re-assemble everything before I mess something else up.

I don't have a wiring diagram, but next time I get a chance to look at one, I'll see if there are any other circuits fed from that fuse.

Thanks, Dennis

[John H.]

Re: C3-'71 Battery Drain

Dennis -

That circuit also feeds the rear compartment courtesy light and the glove box light (in addition to the under-dash courtesy lights, clock, and lighter).

[Dennis M.]

Re: C3-'71 Battery Drain

OK-Problem solved. Thanks to two members who pointed out that the glove box lamp ison the same circuit. Switch not turning light off every time. Slight adjustment took care of the problem.

Thanks all,
Dennis