Gary Maurizi

I'm wiring an aftermarket Sony HU into my 1999 Camaro z28 convertible. I have wired up the crutchfield harness metra part 70-1858 exactly as it is meant to be wired, wiring this to the harness that came with the sony HU.

First when I did this the way crutchfield says to do it, the sony HU has a blue/white wire coming from the harness that is the amp sense wire to turn the monsoon amp off an on, this got wired to a solid blue wire on the metra part 70-1858 wire harness, but this solid blue cable plugs into a pin-spot on the harness that goes to a BLANK PIN SPOT on the STOCK HARNESS, so doing it the way crutchfield says equivalently leaves the blue/white amp sense wire coming from the sony HU connected to absolutely nothing on the stock harness?

I read the monsoon faq, and did see that the monsoon amp is supposed to be signal-sensing, does this mean it does not need the amp sense wire connected?

I also read the stock pinout for the factory stock harness and saw that there IS AN AMP SENSE WIRE ON THE STOCK HARNESS, BUT IT GOES TO AN EMPTY PIN ON THE METRA 70-1858 harness? See this line in the Monsoon Audio FAQ:

11 - GRAY - (Convertible) amplifier sensor

Does this mean i need to do something special for the convertible model only, that is different than the t-tops? the crutchfield order form did not have an option to select convertible or t-top and i think this metra part harness is a generic peice?

So what is the deal here? it looks like the crutchfield instructions are intentionally leaving the amp sense wire from the HU disconnected from the monsoon amp?

I personally spliced into the stock small grey amp sense wire on the stock harness, and the blue/white on the sony harness, and connected them with a jumper just in case... but what is up with this? did crutchfield send me the wrong stock adapter wiring harness? or is the amp sense wire supposed to be disconnected?

I am asking this because ever since installing this sony HU my battery has been draining over-night, and I have meticulously gone through my solder joints and even put tape over the heat shrink, checked continuouty on the harness, checked that there are no shorts, all of this three times over. After doing all of this, I realized that the way crutchfields instructions say to wire it up with the harness they provided, the sony's blue/white sense whire goes to the metra harness solid blue, then to an empty pin on stock harness (not connected).

Sorry for the ranting, this is day 5 and I have not got this figured out. Any help is much appreciated.

Thank you so much,
GM

WhiteBird00

iTrader: (4)

First, there is a difference between an amp sense wire and a remote turn-on wire for an amp. An amp sense wire tells the head unit when an amp is connected. A remote turn-on wire signals the amp to turn on when the head unit is turned on.

The Sony head unit has a remote turn-on wire as does the Metra harness adapter. This wire is unused in a Monsoon system because the amp uses signal sensing to turn on.

The factory head unit has an amp sense wire (convertible only). This wire is also completely unnecessary for any aftermarket head unit installation.

Besides, even if either of those wires was needed for your installation (such as when using an aftermarket amp), they would not cause the problem you describe... quite the opposite, the amp would not power on at all without the remote turn-on signal so there would be no battery drain.

The most common cause of the problem you describe is connecting the constant (battery) power and ignition-switched power in reverse. The red wire in the harness adapter is ignition-switched power which goes to the yellow wire in the factory harness. The yellow wire in the harness adapter is constant power which goes to the orange wire in the factory harness. Normally, aftermarket head units will use the same wire colors as the harness adapter so it's a simple matter of matching the colors for connection. But I'm not sure about Sony - especially after you mentioned that they have you connecting the blue/white (remote turn-on) wire to the blue (power antenna) wire.

Greg99LS1

iTrader: (1)

I'm having the same problem with our '99 Trans Am convertible after a Pioneer AVH-4100NEX install. The battery and alternator have been checked and are both good.

After sitting overnight, the battery is completely dead, so there is a slow power drain, I suspect the monsoon amp. I showed this topic to the guy at the stereo shop, he didn't seem to think anything of it regarding the constant/ignition-switched wires, but I think it may very well be the problem.

If it is the issue, I'm not sure how to switch those wires as described. I saw how the harness adapter connected the factory harness to the wiring pigtail supplied by Pioneer that plugs into the back of the head unit.

Does the red wire from the Pioneer plug connect to the yellow wire on the harness adapter?

Does the yellow wire from the Pioneer plug connect to the orange wire on the harness adapter?

This is aggravating, to say the least....the unit looks really great in the car:

WhiteBird00

iTrader: (4)

Yes, Pioneer harnesses use the same color scheme as the adapter harnesses from Metra and Scosche - the color scheme is a standard in the auto audio world.

So, if you were splicing the Pioneer harness directly to the factory wiring (not a good idea) then the red wire in the Pioneer harness goes to the yellow wire in the factory harness and the Pioneer yellow goes to the factory orange.

If you're using a harness adapter then the wires in the Pioneer harness get matched color-for-color to the adapter harness (red to red, yellow to yellow, etc.).

Greg99LS1

iTrader: (1)

OK, thanks! I'm using a Metra harness adapter, modifying (mangling) the factory harness was out of the question.

Knock on wood, we seem to have the problem solved, the car started up strong just a few minutes ago, no hesitation on ignition.

HappySalesman

iTrader: (3)

Your issue is that the monsoon amp is not shutting off. I've dealt with this issue dozens of times in it he signal sensing amps from monsoon (in looking at you Volkswagen).

What you need to do is wire an interrupt in the constant power for the amplifier. This is easily done with a relay. Put pin 85 to ground and 86 to the remote turn on wire from the deck (blue/white). Find the constant for the monsoon amp and cut it. One side goes to pin 30 of the relay, the other goes to pin 87. Now whenever the deck turns on, it'll activate the relay and send power to the amp. As soon as the radio shuts off it kills the amp

1999nbmZ

+1

Follow HappySalesman's instructions, and the draw from your amp will be gone.