So, one day I get into my camaro, turn the key to start it, and the entire electrical system shuts off. Well I assumed it was the VATS freaking out, it does that about once or twice a year. For years the car has randomly displayed a steady security light without issue.

After 10 minutes I tried again, but the car wouldn't respond. A clicking noise began to happen behind the glovebox. Research indicated this was a relay in the BCM. Leaving the door open with the key in the ignition would cause the chime to distort along with the clicking of the relay.

The instrument panel only displays the air bag light and the service engine light when turning the key to start. Everything electrical no longer works.

The battery discharges itself on the relay clicking over time, I've recharged it several times already. The voltage is good. At a loss. Do I need to replace the entire BCM?

 

If you have a spare battery, try it, at least to remove any doubt.
A bad battery can still register 12 volts, but not have the sufficient amps to crank the engine over.

 

Its not a matter of cranking power. The car is suffering a complete electrical failure, including accessory electronics.

 

Something to check and clean then would be your connections at the battery, positive battery connections at the junction block, and your grounds.

 

The terminals are clean, the battery is good, the electrical problems are scattered. Most everything does not work. SOME VERY SMALL THINGS continue to operate, such as the red security LED in the defrost vent, the air bag light when the key is turned, the check engine light when the key is turned, as well as a relay in the BCM that clicks rapidly while the door is open, which also distorts the key in lock door chime.

Everything else does not work as in does not respond at all. Amps are good, voltage is good. I believe I traced it to the BCM but my problems seem to be much, much more involved than other BCM issues I've read about on the internet (intermittant windows and radio, I've never had that issue)

 

check the voltage at the power juction. gotta find where its losing its amps. have you tryied unhooking any aftermarket amps? sure sounds like a poor connection somewhere, did you clean the battery terminals, sometimes they can get a layer of carbon or something and it looks sorta like the lead and will let a light flow of amps through but if you put some juice to it it fails. sooo if you cleaned it with wire brush or one of them terminal cleaner brushes then your good to go there. ive used a pocket knife in a pinch. wire brushing the wire ends on the wires to the junction box is a good idea.

 

hmmm, me thinks the rationale behind your comment was missed. I'll cut and paste your statement a few times because it must have been hidden within your lengthy post


If you have a spare battery, try it, at least to remove any doubt

If you have a spare battery, try it, at least to remove any doubt

If you have a spare battery, try it, at least to remove any doubt