Dead Battery 2005
Thread Starter
Heel & Toe
Joined: Dec 2019
Posts: 24
Likes: 2
Dead Battery 2005
I have a Priority Start attached to my battery due to battery drainage. Until recently it has worked as designed. When a drain is detected it disconnects the battery which stops the drain. I can start the car.
Recently, when this disconnect has happened, the battery voltage has dropped to 10 volts and the car won't start. When I jump the car and start it, the radio and heater are on. After I start the car the voltage reads 14 volts, normal.
Every time I leave the car for only a day this happens.
Has anyone else experienced this?
Recently, when this disconnect has happened, the battery voltage has dropped to 10 volts and the car won't start. When I jump the car and start it, the radio and heater are on. After I start the car the voltage reads 14 volts, normal.
Every time I leave the car for only a day this happens.
Has anyone else experienced this?
Last edited by Pozzo6819; Feb 8, 2021 at 03:03 PM.
Team Owner
Joined: May 2000
Posts: 53,727
Likes: 5,612
From: Plantation Florida USAF(Retired) 1966-1990
U.S. Air Force
St. Jude Donor '05 thru '26
NCM Sinkhole Donor
You have to have short, first how old is the battery, might have a bad cell.
I have 2005, and it stays in the garage with no battery tender, for weeks and starts right up.
I would say you have draw on the system someplace, might be in alternates can look good, charge well, and still draw on the battery when sitting.
Good luck!
I have 2005, and it stays in the garage with no battery tender, for weeks and starts right up.
I would say you have draw on the system someplace, might be in alternates can look good, charge well, and still draw on the battery when sitting.
Good luck!
Thread Starter
Heel & Toe
Joined: Dec 2019
Posts: 24
Likes: 2
Thanks for responding. I replaced the battery in March 2019 with an Optima Red Top; 720 CCA
I'm surprised that your battery doesn't drain, as I thought all 2005's had Dead Battery Syndrome. Dead Battery Syndrome is the reason I installed the Priority Start years ago.
I suppose I do have a short. I know nothing about electrical systems so I'll bring it to my mechanic to check it out.
I just pulled the fuses for the radio and the heater to see if that helps.
I'm surprised that your battery doesn't drain, as I thought all 2005's had Dead Battery Syndrome. Dead Battery Syndrome is the reason I installed the Priority Start years ago.
I suppose I do have a short. I know nothing about electrical systems so I'll bring it to my mechanic to check it out.
I just pulled the fuses for the radio and the heater to see if that helps.
Melting Slicks
Joined: Nov 2007
Posts: 2,279
Likes: 550
From: Pittsburgh PA
St. Jude Donor '10-'11-'12-'13-'14
Direct from the Master:
Yep, the original firmware had problem with the modules not going into sleep mode, and GM issued updated firmware TSB reflashes for the 2005 cars.
Note, had a problem with the cd radio firmware as well (static) and even had a firmware update for the radio's too. Some of the update firmware's were corrected on the laster 2005 runs, will some of them where not corrected for another year instead.
If someone around you has TIS2000, it will have the latest firmware for both the BCM and the RCDLR that you want to flash into the these modules.
Also, since you already have the car hooked to TIS200, not a bad idea to just go through all the modules to see if there is updated firmware for them as well. Hence in TIS200, it will be only searching for the firmware for your Vin number, and easy to compare what is flashed in, verses the list of firmware by dates in the list that can be flashed instead.
As for disconnect, instead of solving the problem, will have to remember to re-index the windows and reset the time on the radio (if stock) when you power the car back up each time.
Lastly, the CTEK MUS 4.3 put out about 4.3 amp charge, so if its not keeping up with the parabolic draw, something is very wrong and its more than just a module or two not going into sleep mode the problem at hand.
Note, had a problem with the cd radio firmware as well (static) and even had a firmware update for the radio's too. Some of the update firmware's were corrected on the laster 2005 runs, will some of them where not corrected for another year instead.
If someone around you has TIS2000, it will have the latest firmware for both the BCM and the RCDLR that you want to flash into the these modules.
Also, since you already have the car hooked to TIS200, not a bad idea to just go through all the modules to see if there is updated firmware for them as well. Hence in TIS200, it will be only searching for the firmware for your Vin number, and easy to compare what is flashed in, verses the list of firmware by dates in the list that can be flashed instead.
As for disconnect, instead of solving the problem, will have to remember to re-index the windows and reset the time on the radio (if stock) when you power the car back up each time.
Lastly, the CTEK MUS 4.3 put out about 4.3 amp charge, so if its not keeping up with the parabolic draw, something is very wrong and its more than just a module or two not going into sleep mode the problem at hand.
Team Owner
Joined: May 2000
Posts: 53,727
Likes: 5,612
From: Plantation Florida USAF(Retired) 1966-1990
U.S. Air Force
St. Jude Donor '05 thru '26
NCM Sinkhole Donor
Instructor
Joined: Dec 2006
Posts: 208
Likes: 126
From: Golden Colorado
I have a question about the Priority Start unit. I also have a 2005 and find that if I leave the car off the tender for more than about 2 weeks I run the risk of a dead battery. With the Priority Start unit have you had any issues with the radio forgetting the settings, or the seat memory getting lost, or the windows needing to be reset? When/if my battery goes dead all of those items have to be re-done and it's a real pain. Does your remote door clicker still work when the Priority Start is in use and has disconnected the battery to keep it from going dead?
Thanks,
Richard
Thanks,
Richard
Last edited by w4rmk; Feb 13, 2021 at 10:23 PM.
Thread Starter
Heel & Toe
Joined: Dec 2019
Posts: 24
Likes: 2
The Priority Start is intended to cut off the circuit from battery to electrical circuit when it detects a large draw. This prevents the battery from going dead. If left long enough, however, the battery will still drain to the point of being dead.
When the priority start has cut off the circuit I can still start the car. I get into the car through the door cable in the trunk. I wake up the system, reconnect the Priority Start, by turning on an air compressor that I keep in the car. At this point the battery is still has enough charge and the windows index and everything is fine.
When the battery goes dead the windows won't index. I drive the car about 15 or so miles to reset the system. After that the windows index again. I don't have any presets on my radio so I don't need to reset.
When the priority start has cut off the circuit I can still start the car. I get into the car through the door cable in the trunk. I wake up the system, reconnect the Priority Start, by turning on an air compressor that I keep in the car. At this point the battery is still has enough charge and the windows index and everything is fine.
When the battery goes dead the windows won't index. I drive the car about 15 or so miles to reset the system. After that the windows index again. I don't have any presets on my radio so I don't need to reset.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
Le Mans Master
Joined: Jul 2010
Posts: 6,008
Likes: 723
The Priority Start is intended to cut off the circuit from battery to electrical circuit when it detects a large draw. This prevents the battery from going dead. If left long enough, however, the battery will still drain to the point of being dead.
When the priority start has cut off the circuit I can still start the car. I get into the car through the door cable in the trunk. I wake up the system, reconnect the Priority Start, by turning on an air compressor that I keep in the car. At this point the battery is still has enough charge and the windows index and everything is fine.
When the battery goes dead the windows won't index. I drive the car about 15 or so miles to reset the system. After that the windows index again. I don't have any presets on my radio so I don't need to reset.
When the priority start has cut off the circuit I can still start the car. I get into the car through the door cable in the trunk. I wake up the system, reconnect the Priority Start, by turning on an air compressor that I keep in the car. At this point the battery is still has enough charge and the windows index and everything is fine.
When the battery goes dead the windows won't index. I drive the car about 15 or so miles to reset the system. After that the windows index again. I don't have any presets on my radio so I don't need to reset.
Thread Starter
Heel & Toe
Joined: Dec 2019
Posts: 24
Likes: 2
No, I open the trunk with the key and then pull the cable that unlocks the driver's side door.
Page 2-15 of the owner's manual :"If your vehicle has lost battery power, open the hatch/trunk using the vehicle key. The key lock cylinder is located on the rear of the hatch/trunk lid above the license plate. Turn the vehicle key clockwise in the lock." Inside the trunk, on the driver's side, is a cable that you pull to unlock the door.
Page 2-15 of the owner's manual :"If your vehicle has lost battery power, open the hatch/trunk using the vehicle key. The key lock cylinder is located on the rear of the hatch/trunk lid above the license plate. Turn the vehicle key clockwise in the lock." Inside the trunk, on the driver's side, is a cable that you pull to unlock the door.
Team Owner
Joined: May 2000
Posts: 53,727
Likes: 5,612
From: Plantation Florida USAF(Retired) 1966-1990
U.S. Air Force
St. Jude Donor '05 thru '26
NCM Sinkhole Donor
I have 2005, and sits sometimes in the garage for 4 weeks, and starts right up, with no problems.
Team Owner
Joined: May 2000
Posts: 53,727
Likes: 5,612
From: Plantation Florida USAF(Retired) 1966-1990
U.S. Air Force
St. Jude Donor '05 thru '26
NCM Sinkhole Donor
I can also tell you, couple months ago I went to the range, and when getting ready to leave popped the hatch, than got in the car, closed the door, and hit the start button, car was completely dead, couldn't get the door to open, had to use the lever.
Just shows you battery can get weak or dead in hours. I only at the range for two hours, drove down for hour, and two hours dead battery, good thing a member had battery booster to jump. I never had reason my battery was going dead, only 2 1/2 years old.
Instructor
Joined: Dec 2006
Posts: 208
Likes: 126
From: Golden Colorado
My 2005 is a manual and I usually don't let it sit for more than about a week before I put it on the tender. If I try to push it to 2 weeks then I risk a dead battery when I go to start the car.