snksknr94

Everybodys an expert on the internet , do whatever you wanna do. Lee I'll find you a place to pick up 12v under the hood. I replace BCM's quite frequently, more so than any other module in a vehicle. So I personally wouldn't start probing wires coming out of the BCM, but what do I know.

snova031

Never said I was an expert at anything

Don't know what the attitude is for...all I know is that I've tapped into the 12v in the BCM on a ton of newer GM's and I've yet to have a problem...but what do I know.

SoCalHHR

How to "play nice" on a web forum and that counts for something!

"It's a cruel, cruel place...ChevyHHR.net" (our new slogan?)

snova031

lol

snksknr94- didn't mean to come off as being an ass or anything...just giving my personal experience on the subject.

snksknr94

**** it, I'm done trying to help people on this site.

Lee there is a post terminal at the fuse block that has power coming to it directly from the battery, yuo should be able to pick up 12 v there, I'll varify after lunch. This maybe the one you already tried though. I'll try and put a load on it and see if it goes dead.

Lee3333

I tried both of the terminals outside of the fusebox. I even tried connecting the compressor directly to the post for jumping the car, but it only gave a weak sound. I believe this indicates not enough current. I don't understand why it wouldnt work.

My first attempt at hooking up the airhorns was to use the post for the powersteering. It worked for a while (in the driveway), then suddenly stopped (while I was driving). Perhaps the additional strain of the horn and P/S was too much for the circuit? But after that, I could not detect any power in any of the connections at the fuse box (but mysteriously everything still worked). Just as strangely, one day I checked and the power was back. My siren began working again. It is all too wierd.

snksknr94

You should be able to pick up 12 volts at the front post to the left of the fuse block, the one under the red cover. I did notice that the post seems to be coated, I had to scratch my test lamp around a bit before it would light. Maybe take some steel wool or fine grain sand paper and rough up that post, and try it again.

Lee3333

Thanks. I'll give it a shot later, and let you know what happens.

Lee3333

I tried tapping into the terminal for boosting the car with the same result-nothing. It gets 12 volts as shown by test light, but will not drive the compressor. When I tried both the test light and the compressor at the same time, the light went off when the compressor was connected, indicating serious draw. Note that the compressor was hooked up directly (with fuse) but bypassing relay and switch, eliminating any variables.

What gives-what is wrong with this connector? I did this at my friends auto stereo/alarm/custom installation shop with a very experienced tech. He suggested running a test line direct from the battery, first ground then power to see which connection is not adequate, although we are both reasonably sure it is the positive end. But if the boost terminal on the HHR were actually connected directly to the battery, then it would work. So something is in there blocking the power.

SoCalHHR

You are correct! There is a circuit breaker there. When it detects serious draw, it disconnects to prevent excessive battery drain. I'm not sure where you are going to pick up a 20A circuit from the underhood fusebox without encountering this problem.

You can tap from the center console fusebox - off the main red wire entering the BCM, but this would necessitate running a "hot" wire through the firewall grommet (near steering column), to get it underhood. I'd only do that as a last resort, as having a hot wire ground on the firewall could cause a nasty short!