Gloryhog

Today I hooked up a test light to confirm a voltage drain on my 66, and I got a rhythmic on and off light together with what sounded like the turn signal flasher going on and off in time with the light. It stopped when I replaced the negative cable back on the terminal. Very strange, no? Does anyone have any idea what this might indicate? Thanks

DUB

I have no clue because I do not use the 'test light' method of finding a power drain. A test light is not conclusive....because it can not actually tell you how many amps the system is drawing. And going by the intensity of the test light bulb...does not work either because I can show that if I use it on a 1984-1996 Corvette...the test light would 'say' that i ahve a huge drain..when in actuality I do not.. That is why I use a tool made for this specifically so I can see how many amps the system is drawing.

DUB

Gloryhog

I'm just curious--How does your answer move the ball forward?

65GGvert

Does your 66 have a four-way flasher?

DUB

By possibly using the correct tool for the job and see if it reacts the same....and you will know how many amps the system is drawing.

Having your turn signal flasher making noise...as you described it... but did not confirm it...makes no sense...because the turn signals are not on when the ignition key is off....so....thus...they can not drain the system...if it is still wired correctly.

The ONLY circuits that can drain a battery are those circuits that are HOT all all times....meaning they do not require the ignition key to be ON to operate....such as headlights, horn, brake lights, interior lights and others depending on year model.

DUB

Gloryhog

No four way flashers.

Duck916

Do your turn signals work correctly?

You did this because you have a current draw somewhere, right? I'm thinking it's somewhere in the turn signal circuit. That might be why the draw of the test lamp causes the flasher to operate. Just a thought....

Gloryhog

Yes and Yes, they operate properly. I'll see if I can pull that fuse (if there is one), and see what happens with the test light.

GUSTO14

In the past many folks added 4-way flashers to their Corvettes before they became standard in 1967. Back in the 60's most auto parts stores offered a generic kit that could be wired into most vehicles of the day that didn't have them. These are typically wired directly into the battery so the circuit is hot all of the time.

It's possible that someone did this to your car in a "previous" life and it is no longer functioning. You mentioned in your first post "a rhythmic on and off light together with what sounded like the turn signal flasher going on and off". If you did hear a clicking sound, you might try to see if you can run down the location of that sound and see if you may have the remnants of an earlier 4-way flasher mod in the car.

Additionally many of the early alarms that were offered as add-ons by many auto parts stores used a similar flasher type device to activate a horn (alarm) when the alarm was triggered.

Finding the source of the sound you heard may reveal the source of the drain.

Good luck... GUSTO

Gloryhog

Thanks. I will add that to my action plan today.

6T7L71CPE

The original clocks, also always powered, have a solenoid ratcheting mechanism, not sure how fast the cycle is compared to your s.

Gloryhog

Yes, my clock has been rebuilt and keeps almost perfect time. This is something completely different. It's quite vexing to me that it quits when I replace the negative cable on terminal. So, what is it about hooking the test light between the negative cable and negative battery terminal that sets off this effect? Why doesn't it "click" when full connection is made?

6T7L71CPE

Maybe not enough amperage though the bulb to fully operate what is drawing the current. I'd pull all fuses and disconnect the clock and try your test again.

Gloryhog

Tried the test again, and when I opened up a door to find the source of the clicking, the courtesy lights came on, the test light went solid, and the clicking stopped. The clock struggles to run when the test light is hooked up, but the clicking is definitely coming from close to the fuse block.

I also discovered that the combination of my large age-stiffened body and a tight cockpit is preventing me from getting a good look at the fuse block. I'm going to either have to get myself a young wiry assistant or disassemble the car. I'm off to find a multimeter and an assistant.

Gloryhog

UPDATE:
After being schooled by DUB, I went and got a multimeter and slapped it on there in place of the test light. Lo and behold there was no clicking, and the clock ran smoothly. After everything settled down, the steady draw was .11mA, which I believe represents just the clock.

Now I have to consider the heretofore unthinkable----no voltage leak at all but a failing Optima red top which is less than a year old and cost a small fortune. Additionally, since I had aftermarket A/C installed, I will have to practically disassemble the car to get it out. I bought the Optima to avoid just this situation. Silly me.

Thanks to all who contributed to this ill-fated thread, especially DUB who first set me upon the path to a conclusion. I wonder if there's a way to drop that sucker out the bottom?.......

Duck916

Before you go and dig out the battery, have you verified that the car is properly charging it while you're driving? Forgive me if I'm wasting your time, but I'd make sure that my charging system was producing a solid 13.5-14.2 volts when the car is running and/or I'd charge the battery with an external charger and see if it holds the charge.

Gloryhog

That is good thinking. New high amp alternator installed when I had the air put in. Gauge shows it charging even at idle with air running. I have charged it several times and then found it down after a few days with no driving involved. I will double check the output to be sure.

C-1 Generation 2

Is it possible that your AC compressor switch is not wired through your ignition switch and you left the air on? A friend with a 32 Ford had his battery run down after just sitting a short while at a car cruise before because of that.

6T7L71CPE

Do you have Vintage Air? Read this post: https://www.corvetteforum.com/forums...-valve-x2.html

Gloryhog

Thanks for the heads up. Mine is Classic/Old Air.