So last night I changed the intake manifold gaskets, and fuel pressure regulator on my girlfriends 02 Monte, 3.4. Disconnected the ground from the battery, before I did anything. Get her all buttoned back up, hook the ground back up, and call it a night. I go back out there this morning to put coolant in it, fire it up, and I have no guages or radio when the key is in the on position. The gauges don't run their little test to see if they work when I turn the key on, they just kick up a tick. If I turn the key to accessory, the gauges will read fine, and the radio works. As soon as I turn the key back to the on position, the gauges cut out, and the radio turns off after 5 sec. I've checked every fuse in the engine bay, and inside. I have no clue what the problem is, I'd greatly appreciate if someone could lend a helping hand. Thanks.

 

Would I be correct to assume that the gauges run through the radio? Then I would just have to figure out why the radio won't work with the key in the on position.

 

Does the engine run? Maybe a disconnected alternator wire? Don't know what that would do, but just a thought. More likely a bad ignition switch. Is there any clicking or lights flickering?

 

Could be the security system was never disabled, and a security relearn needs to be done?
See the post Rickomatic JUST put up:
https://montecarloforum.com/m_84729/tm.htm

 

It starts, runs, drives. No gauges, no radio.

I don't think the red light on the radio has ever blinked, which would mean it's disabled, correct?

 

I'm now about 63.43% sure that it's the BCM.

 

Maybe the radio is locked (?). Mine is an '02 and the radio is supposed to be disarmed/disabled before removing the battery cables because it can lock the radio. I don't have the code to unlock it so if it happens, I'll have to drop $100 to hook it up to a Tech II machine to get the code. If a thief steals the radio all they'll get is a big paperweight because without the vin# they can't get the code (that's what I was told anyway). The older models are easier to get the code.

 

There's some combination of buttons to press to get the code out of it, pick up a haynes manual it's in there somewhere under radio stuff I believe. The car runs and the radio works, but not at the same time, so it can't be that. I just got a new BCM from GM for $160, I'm gonna put that bad boy in when I get home from work.

 

I never found it in my Haynes manual for my type of radio. Found lots of stuff on the net about getting the code from the older style but not mine. When I asked at the dealer when I took it in to get the catalytic converter replaced, the guy said he'd get it. Then later told me mine would have to be hooked up to a Tech II to get the code, couldn't do the button thing on it.

But you are probably right, it shouldn't work at all if that's the case. Good luck and let us know.

 

Changed the BCM, and the damn radio **** kicked on! Cycled the ignition, and bypassed it- EVERYTHING WORKS!!! Well minus the radio. I'm about to call my buddy and see if he can sneak me in at the dealer and get it sorted out.

Thanks guys.