Audio Systems: Deck turning off when parking lights turned on, volt source, ford taurus

Question
I feel almost embarassed asking this. This is the 8th deck I've installed in my cars and they always powerup on the first try.
I'm installing a deck into an '89 Ford Taurus and I know the Ford wires codes are hopeless., but I've found what they are, comparing various colours with what they should be and where the wires actually appear on the harness. The speaker harness is obvious but the power harness is the one I'm doubting.

Here's the problem:
Key's in on Position or Accessory. - deck power is on only showing clock and dimmed so (it's not actually powered up). So I turn the power on from the deck...it powers up and I can do anything on it. Once I take the Key out, and put it back in, it's likes the deck didn't keep the memory.
When the decks fully powered up and I turn on the parking lights with dash board lights. The deck shuts off. and I have to turn the lights off to get the deck to turn back on.

I wired up everything except for the Dimmer wire. I tested each wire too before actually hooking them up to make sure. Varified the Constant 12V - always showing 12V's

Memory-Acc 12V - only 12V when key's in On or Acc position.

Ground - always nothing.

Dimmer - it ranged from 1V to 6V's depending on what you select with the dimmer dial. (this of course dims everything - all dash lights).

It seems to me that something is grounding out. or maybe one of the wires is changing polarity (Positive to Negative or vice versa). Should I wire up the dimmer wire with one of the 12V's? (probably the 12V Accesory?)

I'm baffled..:s . It's ironic that my first car was a '90 Topaz (which I still have) and the wiring should be the same?)

I know this is probably a simple answer....lol


Answer
Matthew,
The memory wire (yellow)from the stereo must be connected to a 12 hot at all times and the main power wire (red) must be connected to a 12 volt source that is controlled by the key/ignition. measure the ground wire with a volt meter and check to be sure that the ground stays at ground when the parking lights are on. If you turn on the lights and the ground wire? that you are using changes from a ground to any other level/voltage the wire that you are using for a ground can't be used. You can ground the stereo to the metal firewall of the car. The dimmer wire in the harness for the stereo can be connected to the dash dimmer circuit or it can go to the parking light circuit.


TOM,
T&D ELECTRONICS
tdeser@zoominternet.net