QuestionHi there I currently bought a new deck for my vw jetta 03. I got the wiring harness to make a quick easy install that I thought I could do myself. Everything was going good until I went to turn the car off and the cd player decided not to. What is it that I did incorrectly?
AnswerWe are probably talking about 3 wires, unless you are using the remote wire, ect. If hooking it up as-per instruction does not work, you are concerned with ground, power and memory, first. Since it is turning on I will presume that the ground is ok, for now.
It is very likely that either you have the memory wire (which needs 'constant 12v') and the power wire (which needs 'switched 12v' via the Key) from the headunit reversed or the adapters wires are reversed to the headunit.
If the settings and radio presets are lost after the key is off for a bit, this is probably the case.
You may have hooked both of the mem and power wires to the same (always hot, constant 12v) lead on the adapter kit. Do not do this.
The kit should have separate wires for each of the headunits' separately fused wires.
Double check your connections from the decks' power and memory wires to the adapter wires and you should find a resolve which should get you towards normal, very soon.
Also, you may want to Ground the headunits' ground wire directly to the vehicle metal chassis. I generally never trust a factory headunit ground and I rarely advise a novice to use one since they can be extremely problematic to the less-than-experienced. So, unless it is not feasible/possible to run the ground wire directly to the vehicle metal, you should refrain from using the adapter ground, imho. Some people might say "If the factory ground works and there is no system noise.. why bother" but since I always look ahead to future upgrades, I am not one of those people.
Good luck and thanks for the question.
jm
