I have 2008 C6. It has a battery draw traced to the radio circuit and I was told to replace the radio. If I pull the fuse there is no draw. I changed out the radio to an aftermarket pioneer stereo and have the same problem. I put the factory original back in and have an appointment with Macmulkin to diagnose and maybe repair. Since they are the largest corvette dealer in USA, I would expect them to have a tech knowledgeable enough to diagnose it. I’m 3 hours away from them. Is it worth it? Any comments?

 

You say that you have a battery draw on the radio circuit with two different radios. If you have no radio installed, do you still have battery draw? If so, that draw should be pretty easy to find.

 

I wouldn’t expect much from a dealer Tech to diagnose anything especially when it comes to electrical !!…find an auto electric shop in your area instead…they can diagnose any parasitic draw on any car…Corvettes aren’t special in this regard.

 

I had an auto electric shop diagnose, find the issue and it was the radio. I was told to replace the radio, find a new factory radio, nav, cd player etc. same as original. That would take care of the issue. Temporarily he jumped the radio to a circuit that only powered with the car running. That worked but you lose memory etc. I opted to go with an aftermarket radio so I could have a back up camera and Bluetooth. A friend of mine swapped out his radio so I used the same model etc. he had no issue. New radio didn’t work.

 

How many milliamps does it draw with the power off?

 

if I unplug the radio there is no draw.

 

Walk in the park,and spotty communication from BCM to radio/after market radio adaptor , will bank that its at the X206 splice block.

So here,


And the splice block that all the wires on it are pushed into it, is to the left of the Bose amp, and is the glowing white thing on the top left of below photo.


So unclip the splice block from the plastic is clipped to, turn int upside down, Douche the wires going into the splice block with electrical contact cleaner (get cleaner into the block as well), then one by one, push the wired into the block slightly deeper, then lightly tug back on them to make sure they have a good connection to the splice block connector clips of the splice block bar, and see if that solves the problem. If no, and still have parabolic draw from the after market not going into sleep mode when BCM tell it to, then after market radio adapter is either defective, or not on the most current firmware.

As for oem radio, could have been the splice block with signal from BCM to radio, or could have loose connection in the radio from header pin to control board via one of the ribbons. The fact that oem radio and aftermarket radio having same problems, points to the splice block in the first place; if not a low voltage problem between the Radio connector to BCM for power, or BCM back to engine fuse block on those connectors instead.

 

And just a heads up, half the time you have problems as the X206 or the BCM connector is all due to a clogged HVAC drain line being clogged.

When the HVAC is on (happens in the winter time as well, since heater will turn HVAC on to pull the humidity out of the air on start up, heated air going to the windshield, so it does not fog the inside of the windshield), Hence the HVAC coils are pulling humidity out of the air, that humidty drop as water from coils to the bottom of box, and if drain line is clogged, then water build up to the point in the HVAC box that is just dumps to the BCM area out of the ducts there.

So while checking/contact cleaning the X206 splice block (after you have check to make sure box drain line is not clogged from under car), Good idea to disconnect the car battery, so you can pull the BCM connectors to spray electrical clean them and the BCM pins as well.
Both 2 Blue lock connectors,and the center red connector with 7mm retainer bolt as well..

 

With everything off with meter set at Ma .003 varies too .002.

 

No I dont

 

.003 to .002 Ma

 

3 milliamps is not an excessive draw. That's actually very low. There is nothing wrong with your car.

 

[QUOTE=Dano523;1608908605]Walk in the park,and spotty communication from BCM to radio/after market radio adaptor , will bank that its at the X206 splice block.

So here,


And the splice block that all the wires on it are pushed into it, is to the left of the Bose amp, and is the glowing white thing on the top left of below photo.


So unclip the splice block from the plastic is clipped to, turn int upside down, Douche the wires going into the splice block with electrical contact cleaner (get cleaner into the block as well), then one by one, push the wired into the block slightly deeper, then lightly tug back on them to make sure they have a good connection to the splice block connector clips of the splice block bar, and see if that solves the problem. If no, and still have parabolic draw from the after market not going into sleep mode when BCM tell it to, then after market radio adapter is either defective, or not on the most current firmware.

As for oem radio, could have been the splice block with signal from BCM to radio, or could have loose connection in the radio from header pin to control board via one of the ribbons. The fact that oem radio and aftermarket radio having same problems, points to the splice block in the first place; if not a low voltage problem between the Radio connector to BCM for power, or BCM back to engine fuse block on those connectors instead.

 

Dano523, I believe you solved my problem. I’ve left the battery untended since Thursday and still reads over 12 volts. I should have taken an amp reading before I did any of your recommendations, only after. Readings were at the 2 to 3 reading after, they were much higher when I first started having problems months ago. I’m going to put it all back together and start using it again. I still have to check the AC drain tube. I’ve been chasing this issue for months. Thank you, thank you. I hope it stays, I’ll let you know.

 

Agree, with a 2-3 milliamp draw there’s nothing wrong…what was the draw before ??…if there is no service information stating your max current draw it is usually the RC (Reserve Capacity) of the battery divided by 4 so a 100 minute RC is 25 milliamp…don’t know why you are chasing 2-3 ???