What I'm missing. Removed that Alternator red wire. Removed the wires from the Horn relay. Removed all the fuses under the dash. Unplugged the 2 leads plugged into the fuse box. I know one is for the power windows. Not sure what the other is used for that plugs into the middle connector.

Also removed all the power leads that were connected to the battery. Those are for the Stereo, AMP and vintage air. Switch for the Wipers is OFF.

The shop that did all my work that I'm not going back to replaced the rear harness. From what I can tell it looks like a clean job. Everything works.

I'm just using a Test light right now and it's bright red. Battery will be dead in a few days if I don't keep a charger on it. WHAT I'm I missing to look at???

 

Is this a continuation of an earlier thread?

You need a meter and a plan.

you unhooked a lot and still have a drain?

 

Nope but I followed some of it's advise. At this point its sitting with everything unplugged.
I'm going to unplug the wiper override switch just to make sure. Starter too but everything works well.

 

ok, I am lost.
one thread turned out to be bad battery.

All I can say is hook everything up.
place an amp meter between pos bat post and
pos bat cable.

this will give a baseline of how much drain there is.

with everything connected first
disconnect pos wires from alt/
check the meter for amp drain.
no difference from baseline, hook back up alt.

next would be wiper motor.
unplug pos wire at wiper motor.
check drain on meter.
no change, hook back up.
unplug wiper fluid pump connector.
no change, re plug.

harbor freight has a great meter for a reasonable cost capable of checking many things, amp use is just one.
https://www.harborfreight.com/electr...ity-61593.html

 

Can you describe how you are using the test light? Or, better yet, take a picture?

A multimeter, like the one @calwldlife shows, is a much better option, then we'll have some real data. Or you could remove your battery entirely, and hook the car up to a power supply. Then you'll get a current measurement without risking any fuses (including the one in the multimeter).

 

Auto dome light on will cause a draw. Need to pull the fuse for that circuit. My '80 has it but maybe yours does not?

Hope you have a digital multimeter that can measure 15 full amps DC. INNOVA makes a decent mid range model for a fair price. No need to go crazy here.

Start by disconnecting the positive battery cable and hooking up the multimeter across the positive battery terminal and the loose end of the positive cable. Pull 1 fuse at a time and see what the amp draw on the battery does each time. If no change, put that fuse back in and keep going with the next fuse in the fusebox etc. Repeat until you find the circuit that has a draw.

 

I have them all pulled, all the fuses so no power to the domes, clock or lighter. My meter still shows 2.1 when set to 200m
That's 2 amps correct? This had not changed from before I started disconnecting.

Can't seem to find what is energized. I'll disconnected the wiper motor tomorrow. Everything I've touched is still unplugged for now.

I was using a test light so I could see it from laying under the dash.

 

Check that the 'BLACK' ground wire near the starter is connected to a bell housing or starter bolt and not on the top post on the starter solenoid.


Did you install Vintage air? If YES then disconnect the power to it.

 

Post a photo! When set to 200m it will read up to 200 milliAmps. 2.1 is PROBABLY 2.1 mA, or 0.0021 Amps. The clock draws more than that.

Or it might be 2.1 milliVolts. Or 2.1 meters. We won't know if you don't post a photo, or at least describe how you are using the instrument.

 

First picture is no load. Second is with the headlight switch turned on.

 

put meter on 10amp setting

 

Exactly. You don't know what you're reading right now. The 200 mA setting requires use of the other port.

 

OK 10A shows .21

 

Just for your knowledge as a Flooded Lead Acid battery "ages" they tend to get more thirsty for water replenishment of the electrolyte and their "Self Discharge Rate" will slowly INCREASE. As FLA batteries age they have a habit dropping lead from the plates onto the bottom of the battery. As this lead builds up on the bottom of the cell it can and will short out the bottoms of the cells nearest it. There are many stories about batteries exploding in the car while running, I have seen it myself in an old Dodge Van where it splattered acid all over the engine and engine compartment.

Before going to deep into testing it I would pull the battery from the Corvette, check the electrolyte level and top off if needed (with DISTILLED Water). I would then clean the battery terminals and then attach it to a fairly powerful (more than 15 amp) battery charger. The idea is to charge the battery up until it starts gassing off which should happen at about 15.0 volts. Gassing does two things, it remixes the electrolyte and breaks any stratification of the acid in a battery. Charge that battery up completely and then re-install it in your Corvette. Clean the battery connectors and re-attach them to ensure a good solid connection. IF you have any battery grease you can put it all over the lead and the connectors from the outside as it's job is to keep any water or air from getting to the connected surfaces.

Our older C3's were designed for using a FLA battery and that is the type I still use. There are other options but none as perfect as our good old FLA battery. AGM batteries are a good substitute but retain the possibility that you might make it pop the seal if it overcharged. Lithium batteries are not quite up to speed yet.

ANY time you buy a new battery ALWAYS Charge it before attempting to install it. I like to buy my batteries from shops that sell zillions of them to assure a fresh product. Look at the dates of Manufacture which is posted on many battery lines by the manufacturers. I always buy the most recently made battery. But I will always take it home and charge it until it gases and then let it sit for 1 hour, the new open circuit voltage should be around 12.5-6 Volts.

 

This is a new AGM that I replaced after I got the car back. The old battery was dead after a few days too and it was 10 year old. I thought that may be the issue.

Of course the new battery may have issues too but it charges and holds 12 volts. I returned the battery once and they said there is nothing wrong with it. It's labeled Duracell.

Is .21 considered a lot? I'm don't understand the math to .21 on a 10A multimeter.

Quote "A normal amount of parasitic draw for newer cars is between 50-milliamp to 85-milliamp current draw. A normal amount of parasitic draw for older cars is a reading less than 50-milliamp. Anything past these amounts indicates an electrical issue and should be addressed by a mechanic.Jun 20, 2017?

 

Leave everything disconnected that you have and pull all the fuses. post a pic of your battery connections.....is there any other wires on the terminals other than the lugs?...if not, fully charge your battery then disconnect the leads at the starter and the starter solenoid and reconnect the battery and positive cable. All the battery power runs through the starter. at the starter use the meter between the lug and the starter and see if there is a drain. IF not connect it and see if there is a drain between the solenoid and the solenoid wires.....if not disconnect them all again and See if the battery dies...If it does the battery is bad because there isnt a connection other than the positive and negative leads at this point.
If it doesnt, connect everything back to the starter and disconnect the red leads at the horn relay and test those connections. You should be able to figure out at this point if its inside the engine compartment wiring or inside the interior of the car wiring excluding the lights and wipers.

 

".210" if accurate is 210mA (milliamps). It takes 1000mA to make up a 1 amp draw. Most good parasitic draw readings are around 20mA (.020 amps) or less. The first order is to perform a test is to verify your test equipment before you start isolating the circuits in your car. Start by rolling your drivers window down and closing the door. Hook up your meter in series with a battery terminal to cable. Its always the safest choice to choose the negative terminal is possible and leave the positive connected. Observe the current reading. Next create a known draw by turning on the parking lights only, no headlights or opening the door and observing light operations The reading should increase by 5-6 amps for the exterior for a non led car or a couple amps for the interior lamps non led. Start there and report back on what your finding are.

 

the 10 amp scale setting reads at amp scale.
so .20 is 1/5 of an amp.
too much.

good luck

 

Last October, I suspected my battery of doing the same thing. It would start and drive just fine and one day, I got home and it wouldn't start at all. So I charged it overnight with a trickle charger and that went well. Started right up and then when I got back from my local watering hole, it wouldn't start again. The battery had a four year warranty and I was only two years into it, so I pulled the battery (Everlast) and brought it to Walmart and it tested bad, so they gave me a new one and I put it in. Being the **** retentive, non-trusting SOB I am, I still wanted to test it for a battery draw and found a good you tube video and I got the results I wanted.

So, seeing your predictament, I went out this morning and did the 'Parasitic Draw Test' just to show you. I do auto electrical on the side, so it was easy. My '74 has a lot of electrical mods, like dual electric fans, an MSD, Holley Electric Fuel Pump and an AEM A/F ratio gauge. It all runs off an auxillary Painless 7 Circuit panel that with it's own relay, makes for four relays in my '74. So here are the results. I'll also put a diagram on how it should be hooked up.

'74 with key off = 0.00 amps



With the Headlights on:



Blipping the Holley Fuel Pump on for a second or two:

 

I just drew this, I know, totally crude. But the leads should be in series between the Negative Battery Cable and the Negative Terminal on the Battery. In the pictures, the Red Lead is hooked up to the Negative Battery Cable with the white clip and the Black Lead is hooked up the Negative Battery Terminal with the Green Clip. Just want to make absolutely sure you're doing it right.