No power to HU anymore

durado · December 26, 2004

No a truck butmaybe someone has some idea.

My son bought a system for my daughter's 2003 Grand Am. He started installing it the other day but could not get it to power up with the ignition in the run position. Worked with him tracking down the power and all fuses were verified good. The adapter pigtail plug appears to be wired correctly according to the wire color codes. We reinstalled the stock HU hoping to at lease get that back in for her. Unfortunately now this won't even power up. No codes on the display nothing. Any ideas???

GM-Tech · December 26, 2004

A Grand Am has a heads up display?

trout31 · December 26, 2004

Me thinks HU in this context means "head unit"

trout31 · December 26, 2004

Me thinks HU in this context means "head unit"

GM-Tech · December 26, 2004

Me thinks HU in this context means "head unit"

<{POST_SNAPBACK}>

I hate it when someone uses their own, made up abbreviations. Guess we'll have to wait to see what he meant.

sperry · December 27, 2004

Thar fault lies with many of us - another acronym let out of the cage...

The factory "HU" power isn't controlled directly by ACC-IGN, it is hot all the time and switched on with a "wake up" turn on code over the data bus. That also allows for RAP, so it'll remain on for a while or until a door is opened..

In order to provide switchable power for the aftermarket "HU" he would need to tap an IGN 0 source, similar to connecting to the "I" ("IPC/BFC" ACC) fuse in the left I/P fuse block.

It's a 10Amp, just above the relay (Driver door unlock relay) that's on the lower right of the fuse block. The "hot" source is on the right side of that fuse. Don't tap the left side, the problem with that is that it's a 10 amp fuse that feeds the BCM. You don't want to blow that one. If he pulls that fuse, the side that remains hot in acc mode is the right side. Tap that point and fuse it asap (before it heads off into the wilds of the car interior). Then re-disconnect the battery until the project is buttoned-up and ready to test. DONT cram a lwire in under that fuse, it'll spread the contacts and make it unreliable. It's one that is rather critical.

There are special taps to do this but I don't know the source(s) at this instant.

There is a dark green wire on the rear of the panel that is connected to terminal A7 of connector (1) It leads up to the ignition switch ("Natural" colored connector). You don't need to go there, that was to help identify it.

The C1 connector has 6 columns, and 12 rows, and is the lightest "gray" of the three

The rows count higher as they go away from the 4 smaller connectors. Column "A" for that connector, would be closer to the middle of the block, column "F" at the edge.

So A7 would be close to the inner middle of the entire fuse block. The Dark green wire is circuit 500 which is "hot" in ACC, IGN (& start) but not RAP.

By tapping the acc power there, a short in the aftermarket equipment wiring would only blow it's own fuse, providing a safe size selection was made..

If he doesn't have a voltmeter, get him one, they're cheap.

So there is my 1000 words that you would have fit with a picture. But I can't hotlink to a closed site, or upload a schematic here.... Sorry!

HTH!

...Steve

GM-Tech · December 27, 2004

Thar fault lies with many of us - another acronym let out of the cage...

My question remains... never saw a Grand Am with a heads up so, is it actually available in that model?

03blackburb · December 27, 2004

Thar fault lies with many of us - another acronym let out of the cage...

My question remains... never saw a Grand Am with a heads up so, is it actually available in that model?

<{POST_SNAPBACK}>

Hey GM-TECH. So please inform me as to what a "heads up" is and what it is installed in.

kirkRHughes · December 27, 2004

A “Heads Up” projects a holographic display of your speed and other information on the windshield so you don’t have to take your eyes of f the road to check. I think it came on some Grand Prix’s, mostly the GTP’s. It’s the same thing fighter pilots use for weapons targeting

GM-Tech · December 27, 2004

Hey GM-TECH. So please inform me as to what a "heads up" is and what it is installed in.

kirkRHughes gave a good description, but in cars at least, it is not a holographic image. The digital display is in the top of the dash and it just reflects off the windshield. Pretty much the same effect though. I know Grand Prix has this, as does Corvette, or at least it's an option in those models.