Metalhead140

Hey guys. I haven't started chasing this much yet, was wondering if there are some common things I should check first. My battery dies after a couple of days without running. I tested it and I have a half amp parasitic drain. I disconnected the alternator with no change. I have the interior light bulb removed as I've been working in and out of the car. Haven't spent much time on it yet, but hoping to sort it out this weekend. Seems suspicious for perhaps a 5w bulb somewhere? Any suggestions? I know the process, in terms of going through fuses etc to see what kills it, but figured it would make things quicker to check any known common faults first.

Pretty sure this has been an issue with my car since I bought it - I've normally gone through periods of using it daily (for which it's fine - alt works well), but then having it off the road a month or so to work on it, at which point it's dead. Now that I've been using it with shorter breaks, it's dead after 2-3 days so I started looking into it. Also, the previous owner had a disconnect on the battery terminal, reinforcing the likelihood it was an existing fault!

Thanks in advance...

Street Rat

The courtesy light timer seems to be a popular culprit of current draws. Some posts here somewhere.

NewbVetteGuy

I remember seeing that on here and the factory alarm too- apparently the alarm can go off when you have a problem with the alarm speaker and it will slowly drain the battery, too.

-I use a method to t-shoot unmarked breakers in my house you might use, too:

1. Remove half of the fuses and see if your problem goes away (if so, it something connected to one of those fuses; if not it's something connected to the other half of the fuses)
2. Now remove half of the remaining possible half and see if it goes away
3. Rinse and repeat -it dramatically reduces the number of tests required to get it down to a single circuit



Adam

OMF

I've read on this site that it's a good idea to work your way through the fuse panel pulling a fuse-check to see if the draw is gone, if it isn't, replace fuse then move to the next one.
When you find the fuse that gets rid of the draw, use the wiring diagram to trace each component in that circuit to find the problem.

Good luck

Metalhead140

Thanks everyone! Not looking forward to crawling under the dash to pull fuses, but it has to be done I guess. My car has had some wiring hacks at some point too, though I think I've removed most of them now.

Easy Mike

Do you have a vanity mirror on the passenger's side? Might want to check the lamps.

speedreed8

Glove box courtesy light.

jim in oregon

I believe your '79 has the anti theft alarm system operated by inserting the key in driver's door and turning it counterclockwise..then back to top and removing the key. IF you have an owner's manual, read the instructions on how to set it AND how to deactivate it.. Make certain you use the key to deactivate it. .by turning the key from 9:00 to top and then all the way right..then back to top for key removal..Door is unlocked by turning key to right..3:00 position and the back to 12:00 and removed..I lock my doors by simply pushing the lock button in and closing the doors...not with the key.Jim( no electric door locks)

SwampeastMike

The alarm is part of the CTSY circuit. This seems to be an extremely common problem that begins with a faulty key switch that sets off the alarm continually. The first reaction to this is to disconnect the horn (it's sort of underneath the power brake booster). Unfortunately merely removing the horn doesn't solve the problem as a relay in the center console just behind the astray is still energized when the alarm is triggered.

You may or may not be able to stop the draw by fully unlocking the driver door using the key. Using the driver door key is the ONLY way to arm/disarm the system in a '79. The switch involved is EXTREMELY finicky.

If this is indeed the problem and you don't want to get the system functioning again there are two easy ways to completely disable the alarm system:

1) Remove the driver side carpeted console trim. Remove the electrical connector at the relay just behind the ash tray. Wire colors are orange, yellow, black, light blue and dark blue w/white stripe.

2) Remove the headlight override panel below the steering wheel and the A/C duct. Fish around for a four terminal connector with dark blue w/white stripe, black, yellow and light blue wires. Disconnect that connector.

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If the draw proves to be in the CTSY circuit another fairly common problem is the courtesy light delay timer. To get to it, remove the glove box interior and you'll find it taped to the wiring harness to the right. It is in an orange plastic box.

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New arm/disarm switches and courtesy delay modules are readily available from the vendors. At least one of them sells only the circuit board inside the delay module (you re-use your existing plastic box) at a substantial discount compared to the completely module.

jim in oregon

YEP.. there are Many components involved in the factory alarm system.t top connections, hood, doors..and relays and switches and wiring harnesses.horns..the list is long..
Nicola Tesla would have fun troubleshooting and repairing the system..:
I virtually disabled the system in my '78..inner door panel harnesses, t tops, relay beneath console..etc.
I NOW have a simple but effective 'alarm' system..a black box, 3/4"x2" with an on off switch, 9v battery, and a blue flashing led light. I set it in my ashtray and turn it on at night when the car is parked.About 6.00..lasts forever..Most of the better car alarm systems have a blue indicator light.Won't deter a professional car thief..but NOTHING really will..Jim

Metalhead140

Hmm, thanks for the suggestions guys. My drivers door is dodgy to lock/unlock with the key, so the alarm idea sounds promising...

SwampeastMike

Then if you verify that the draw is from the CTSY circuit I highly suggest my #1 alarm disconnect option as the easiest way to both confirm and solve.

Metalhead140

Will do, thanks! If that turns out to be the problem then I will have to decide if I want to repair, remove, or replace...

SwampeastMike

If that arming switch is the problem and you go the repair route be aware that while replacing the switch (it will come with an attached harness) isn't too bad of a job getting that finicky switch adjusted properly around the cylinder can be a real pain. Before doing this be CERTAIN that the dedicated alarm horn is both connected and working! You want to be sure the switch is installed properly BEFORE you button everything up again!

I must disagree with the poster who said that Nikola Tesla would be proud of the alarm system due to its complexity. Whoever said that knows little about Tesla or that alarm system. The system is actually very simple and primitive. It is nothing more than 5 switches (each door, each t-top and the hood) that give a path to ground, arming and tamper switches at the driver door, a SPST relay and a horn. Combined with some improvements that made it difficult to "hot wire" a start it is though reasonably difficult to defeat. A substantial improvement came in '81 or so when the system incorporated ignition kill.

Other than the lack of ignition kill the main flaw I find in that factory alarm system is that while it incorporated the "long needed" T-top protection it also became impossible to arm the system without the t-tops installed. I'm about ready to make improvements to my '79 that solve both of these problems but am having surprising difficulty finding suitable relays.

gkull

My 79 began killing batteries after a completely new hot rod motor install. I eventually traced it down to my aftermarket digital multi spark and dizzy setup.

My fix was to install a battery shut off switch.

http://www.batterymart.com/p-battery-cut-off-switch.html?utm_source=Bing&utm_medium=C PC&utm_campaign=PLA&utm_term=keyed%20bat tery%20shut%20off%20switch&creative={cre ative}&device=c&network=o&matchtype=e

jim in oregon

Swampeast Mike..

I know much more about TESLA than most people.and I DIDN'T say he'd be PROUD.. of the system..Jim I am a retired degreed electrical -mechanical engineer..and Tesla was one of the most amazing men.

Q:I must disagree with the poster who said that Nikola Tesla would be proud of the alarm system due to its complexity. Whoever said that knows little about Tesla or that alarm system. The system is actually very simple and primitive.

SwampeastMike

Sorry for being snarky Jim. I have a pinched nerve in my neck that's gone bad and it's put me in a rather foul mood--in large part because I can hardly do any work rather it be fun (like the Corvette usually) or for profit. Yesterday was when I found out that my insurance (being self-employed the exchanges a.k.a. Obamacare is my only choice) is running out the clock for a much-needed MRI as they're leaving my state at the end of the year and I'll be with a new company. It's much cheaper for them to pay for narcotics than the MRI and ensuing surgery.

jim in oregon

Mike..no worries..hope you feel better soon!
When the world finally gets hold and employs Tesla's genius.. MUCH will change for the better..Jim

jim in oregon

Mike..no worries..hope you feel better soon!
When the world finally gets hold of and employs Tesla's genius.. MUCH will change for the better..Jim[/QUOTE]

SwampeastMike

[/QUOTE]

I couldn't have said it better! We've employed much of his genius but not his ultimates. While this may be wishful thinking, I believe that the purpose of Wardenclyffe was to open a direct transmission line between the earth and the upper atmosphere. That's why the sphere had enormous highly focused UV arc lamps. He then intended to set up a dual resonance--one at extremely high frequency that would transmit via the air and the other at a lower frequency that would transmit via the earth. I suspect the third or "extra" coil in his famed Tesla coil was the link. Combined with an array of similar stations it was to be a worldwide wireless source of usable energy and carrier for nearly unlimited data.