OK -- this one has me seriously stumped.

I've killed two batteries in the last month trying to find this electical draw.

The procedure that I've read here is to unhook the negative battery cable, attach a test light between the neg. cable and the neg. terminal, then pull all the fuses until the light goes out (making sure the door ajar and courtesy lamp pins are in).

Well, right now I have *every* fuse out of the fuse box, both doors are closed, and the test light is STILL on.

The only time the light did anything is when I pulled the clock/lighter fuse, then the lighted "dimmed" but didn't go off.

It makes sense that the light would dim w/o the clock fuse because the clock is supposed to have power with the engine off. Still, the test light stays on even with every fuse removed.

So -- can any electical gurus tell me what the next step here is? Is there any other way to test for a draw?

Thanks - please help I can't afford any more batteries!! :crazy:


[Modified by Corellian Corvette, 12:57 AM 3/9/2002]

 

What year? Some altanators with builtin regulaters can cause a drain [faulty reg.] or exturnal regs. you would hear it click when you remove the batt. cable

 

It's a '73. The alternator is new -- just replaced because my old one was bad.

Thanks!

 

does the 73 have a builtin reg. I cant remember ? even new could still be a problem. Did you try unplugging the alt.?

 

This is me!

I killed 2 batteries :cuss - they got completely drained while the car was sitting in the garage over the course of a few weeks max. I cured the symptom via a switch at the battery terminal. I hear a "click" everytime I connect the battery - sounds like a relay.

Thanks for the alternator idea :) - will test this when the weather gets better.

Chris

 

The electrical system in a car is really quite simple, bitch to get to, but simple just the same.....
so first thing is, pull the connector to the horn relay, the black/green wired thing under that terminal block on the driver's side fender liner, under the outer fender....the one that looks like the distribution power block, it's a dual funchion unit...distrib and horn relay...dumb idea really...
what may be is the horns are bad, and the horn button circuit is drawing current closing relay but horns don't blow....
another thing is the alternator, pull the power output wires, and the 2 pin connector....does light change significantly???
another spot is the starter, where the large battery cable is connected there is another wire there, goes to the electrical circuit...and maybe two small wires, for solenoid controll and ignition....
if the car cranks ok, the 2 small wires are correct....
NOW there is also a large loop end black heavy wire, that goes to ground, engine block, NOT the battery positive at solenoid....common mistake when changing starter....among other things this grounds the heater motor frame and the wiper motor assy.....
pull/test these wires and lemme know what you find...individual email is best as I may not check this post again...depends....
you may also check the brake lights, make sure the pedal switch is adjusted right....
you may also unplug the rear wiring harness by the connector up under the driver's kick panel...rectangular connector, about 6-8 pins per side...maybe a dozen wires in all....
you could unplug the flasher/turn signal wires also...that long flat connector under the steering wheel....

since the fuses are pulled, and the drain is still there, the latter suggestions make NO sense in a stock wired car, but someone in 30 some years may have gronked the system.....hard to say....

GENE

 

Instead of using a test light, use an ameter to measure your current draw. It will be much more accurate than a test light. Most lower-cost multi-testers will allow up to 10 amps of current measurement.

 

The alternator posts may be pointing in right direction. I'm NOT an electrical etch but I've heard this same thing before ... and I've heard it can be cured by putting an external Radio Shack diode inline with one of the alternator wires. Acts like a one-way gate for current flow. I've never done it ... but would like to know the details. Maybe some of the elec techs can chime in here on the diode trick?

More info: A diode (1A-100V) goes inline with the smallest alternator wire (usually brown).


[Modified by jackson, 4:26 PM 3/9/2002]

 

Man -- this sounds like it's going to be a lot of work. :crazy:

OK, so using an ammeter, what should I be testing for and how do I do it? Do I test the terminals at the battery or someplace else?

Is there an acceptible amount of draw? What parts should be getting power?

 

UPDATE!

Ok, I found out what was keeping the light on -- it's the two lead wires going into the top of the alternator (the Brown and Black ones). When I took those off the light died.

I have the brown wired going into the right terminal, and the black one in the left terminal.

Does that mean anything? What are my next steps here? The alternator is new (about 2 months old).

Thanks!

 

I'd say its time to bring the alternator back to where you got it ;)

 

did you check to make sure the alarm system is off? I had a similar problem and it was the alarm system drawing current. The horn was rusted solid so it want making any noise. But when you say you connect the battery and hear a click, that could most likely be the click of the alarm relay. I heard the same click. Is the click comming from around the shifter area? Because that is where the alarm relay is... hope this helps...

 

Okay now this is getting interesting :D All the above answers we're real good I thought for sure it was in the horn relay or alt. Now lets look at what has power all the time not fused...... tic tic.... Factory alarm switch on fender?? neatral safety switch in counsel..... solenoid.... You did remove batt cable at alternator.... not just the plastic plug... dam I'll sleep worse than you tonight. :D

 

Yeah this is interesting!

OK, I have now put everything back together with the exception of the clock fuse and the two wires on top of the alternator.

The light is still off.

I don't here a click when I put the battery on. The Alarm system was repaired but I haven't used it in about a year. I'm not ruling that out as a possibility.

Since I know there is supposed to be power to the clock, I'm not surprised about that.

Now, If I want to take the Alarm system out of the equation, where would I disconnect it to see if it's the cause of the draw?


[Modified by Corellian Corvette, 3:25 PM 3/9/2002]

 

More info: A diode (1A-100V) goes inline with the smallest alternator wire (usually brown).


The 73 came with an internal regulator (which has its own diode that may've failed). You changed alt about 2 months back ... since have had battery probs.

Best bet: exchange the alternator

 

I certainly don't rule out the alternator as a problem, but I was having this draw before hence why I replaced it. So, It's possible they both have the problem.

When I return the alternator what do I tell them? I know they can test so what are they testing for?

Thanks!

 

If you had this prob before alt R&R then may not be alt ...but still could be because your old alt may've had same prob. Fresh ones can too. But, it's not so difficult to remove alt ... take it back ... tell them you suspect internal reg is bad. After only 2 months, they'll probably give you another. If it doesn't solve the problem then you're not out so much time trouble. Just trying to help.

 

Good point. I'll try that this afternoon.

Also, I removed the wires from the Alarm relay in the rear compartment. Light still stays on with the alternator connected. So, doubtful it's the alarm unless that's not the right place to disconnect.

Thanks!

 

Sorry to keep posting on this.

I just replaced the Alternator. Same problem - as soon as I plug the sensing wires in the top the light goes on. Even if the rest of the alternator is unhooked.

Now I'm really stumped here.

MrVette suggested that I might have the wires crossed. Does anyone have a good diagram?

Right now I have the BLACK wire connected to the counter clockwise pin closest to the fender (which I believe is the POSITIVE lead), and the negative lead (closer to the engine block) has the BROWN wire attached.

Still, all my other gauges and everything seem to work fine.

What would happen if I reversed them? Would a draw be the only problem?

Is there a good wiring diagram to look at?

Thanks again!!

 

I would not recommend reversing those wires without a drawing. You could damage the alternator. My guess...since this is the third alt. is that something in line with one or both of those wires is shorting...but its the alt. that is making the circuit good when its connected. Follow the wires back and look for bare spots or anywhere it may be touching metal. This may take some effort..depending on how well they are loomed or where they go, but I think I would do that. I have found many shorts in car wiring that way.....gremlins chew the insulation and such. I think you can safely rule out the alt at this point. My guess....the wires them selves. Just my 2 cents.

Ron