Last week, the vette wouldn't start. I figure it's a dead battery, since I don't know how old the battery is, and it wouldn't take a charge from the charger. I bought a new battery, put a trickle charger on it, and forgot about it, until today, when I went to start it up. The trickle charger was hot to the touch, in fact, it felt like it was hot enough to melt. It indicated it was charging, too. I tried starting it, and the battery is very low; it won't start.

I'm going to start at the battery, work my way up to the starter, then the ignition wire, etc. I have a bad feeling about this. I also have a huge car show I'm supposed to be at tomorrow. #$%$@#@!!!

Time to dust off my memory from high school Auto Shop.

Any suggestions appreciated

 

Battery Drain Test-easy to do with pics

There seems to have been alot of battery drain issues lately.Thought I would write down this fairly easy way to check for battery drain and share it.All you need is an inexpensive 12 volt test light and a short piece of wire. A test light like this one will be very useful for other 12 volt electrical issues.When you go to this link put in your Zip code. http://www.partsamerica.com/productd...egoryCode=3391 Use a bulb type of test light for this test procedure not an LED type.

If you have a C3 and “DO NOT” have delayed courtesy lights and your courtesy lights work this is “my” way to check for battery drain Put both windows down and make sure everything is turned off. Disconnect the negative battery cable and put your 12-volt test light between the (-) battery terminal and the (-) battery cable. Here is a picture to help. With the driver’s door open the test light should be lit. Make sure everything is turned off and close the driver’s door. Wait several minutes (clock step). If the test light stays out completely (no low glow) you have no battery drain.
If the test light is on or even a low glow you have a drain on your battery. (bright bulb is heavy drain ,dim bulb is low drain) First thing I do is push on the doors and watch test light then lean in through the window and push on things with lights like the glove box door, visor light, map lights and the rear center compartment and watch to see if test light flickers or goes out if so you have found your drain. Second thing I do is open the drivers door and remove the courtesy light fuse, if the test light goes out then the drain is in the courtesy light circuit. If the light remains lit continue to remove fuses until the light goes out and that will be the circuit with the drain. If the test light doesn’t go out then the drain is in a circuit not protected by the fuse box.

“Clock step” Info-clocks can be a pain.
Above when you closed the door if the test light went out but came back on shortly afterwards it’s the clock trying to wind and its drawing too much. Disconnect the power to the clock and retest.

If you determine your draw is in the courtesy light circuit disconnect the power to the clock and retest. If this doesn’t eliminate the draw you can now move on to other items on the courtesy light circuit.

OVERNIGHT CLOCK TEST-I use this alot on mechanical clocks on cars that have intermittent power drains.Leave test light hooked up as above and let clock continue to run through the test light all night.If you come out in the morning and the light is off then the clock is in good shape.If the light is on the clock will have stopped and you should have the clock checked or replace it.


If you have a C3 and “HAVE” delayed courtesy lights and they work and turn off after 30 seconds this is “my” way to check for battery drain. Put both windows down and make sure everything is turned off. Disconnect the negative battery cable and put your 12-volt test light between the (-) battery terminal and the (-) battery cable. Here is a picture to help. With the driver’s door open the test light should be lit Make sure everything is turned off and close the driver’s door. The test light should still be lit because the delay relay is engaged. Now (and lets call this the “jumper” step) lean in through the driver’s window with a small piece of wire to use as a jumper (white wire in the pic.) connect the jumper from the (-) battery terminal to the (-) battery cable. Your courtesy lights will come on and the test light will go out --wait for your courtesy lights to go off --remove the jumper lead. Wait several minutes (clock step). If the test light stays out you have no battery drain. If the test light comes back on you have a drain on your battery. Just to be sure do the “jumper” step again to make sure the delay relay was off. If the test light came on again open the driver’s door and remove the courtesy light fuse, if the test light goes out then the drain is in the courtesy light circuit. If the light remains on continue to remove fuses until the light goes out and that will be the circuit with the drain. If the test light doesn’t go out then the drain is in a circuit not protected by the fuse box.

“Clock step” Info-clocks can be a pain. Above after you removed the jumper the test light went out but came back on shortly afterwards it’s probably the clock trying to wind and it’s drawing too much (plus it reset the delay relay). Disconnect the power to the clock and retest as above.

Interior light delay relay –The “jumper” step turns the relay off but the relay will reset and try to turn on the interior lights at the drop of a hat causing the test light to come back on. Any draw will reset it. If you find that removing the courtesy light fuse eliminates your battery draw then the “simplest” way to continue testing is to disconnect the delay relay. In the 5 wire connector you pull off the relay are 2 white wires- connect a jumper between them. This will make your car temporarily a “non-delayed interior light system”. Now you can test using the “DO NOT” have delayed courtesy lights procedure above. If you choose not to bypass the delay relay you will have to use the “jumper” step every time you trigger the relay.


Multimeter Testing—In my opinion you don’t need the multimeter to check for battery drain down to very acceptable levels. However if you want to use one in place of the test light you need a multimeter that will take a heavy amp draw or you will smoke your meter or blow the internal fuse and you must be on the amp.setting not volt setting.

 

Go to sears and get their best computer controlled charger. Disconnect the battery and put on the charger until it says its good. put the battery back in and see if it will start.
If it does, THEN proceed to the troubleshooting.
There are several culprits to the battery discharge problem:
Alternator
Delay timer for the int lights
alarm
stereo
Horn circuit

Do a search for Rogers test thread, he has a good proceedure to track it down.

See where that gets you

 

Ahh, there he is now

 

DW + Six - thanks for the replies. I will get right on it and let you know what I find. I haven't run the car since I bought the new battery, so it's not an issue of the alternator not charging. My alarm system is disconnected. The only new things I've done to this are: installed quartz movement for the clock, and a new stereo. I'm off to troubleshoot now...

 

Geez, I'm an idiot! The power drain was caused by the courtesy light being left on - the headlight switch was turned all the way to the left, leaving the interior light on the whole time...

The reason I guess I didn't notice it, is because my shop if brightly lit, and the lighting inside the car just isn't that bright. In fact, while driving at night, I have found the interior lighting to be worthless. So, I am going pull the fuse on the lights and just not use them at all.

Thanks again for the replies. Sometimes the answer is right in front of me...