# No 12V constant at stereo wiring harness



## 2001SentraGXE (May 28, 2006)

Hey everyone. I really enjoy the forum and have found a lot of useful information on here. I've been reading/searching and haven't found an answer to my problem so I figured I'd post my question. Bear with me as this is my 1st post.

Car = 2001 Sentra GXE
My problem as the title says is no 12V constant power at the factory stereo wiring harness.
About a month ago I started to have problems with my factory CD player/radio. It would work intermittently shutting off (no radio/cd player or clock) and then turning back on. Finally it just died and would no longer come on. No radio or clock. My dash lights, head lights, hazards, dome light and all other common electrical components in the car still worked so I figured the radio just died and needed to be replaced. 

So I went off and purchased a new aftermarket JVC MP3 head unit, a wiring harness and a trim kit (New factory radio is $280). I installed the new stereo disconnecting the (-)ve battery terminal and ensuring all of the connections were good (butt end crimping) and the new head unit was properly grounded. I reconnected the battery terminal and went to see if the new unit worked. Nothing.

Nothing out of the ordinary occured when installing and everything else in the car still works. I got out my multimeter and started checking continuity and voltages. First thing I noticed is that the 12V constant gave a reading of 0.3V when referenced to the chassis ground. The battery is reading 12.6V which is weird as the constant is supposed to deliver 12V regardless. Next I tested the switched 12V wire and it gave +12V with the key in the ignition on position and +14V with the engine running. All of the continuities in the factory harness to the new wiring harness were good and the stereo was grounding to a mounting bracket which is attached to the chassis. I'm guessing this is my original problem. 

I figured I had a fuse problem. Checked every fuse under the dash and under the hood both visually and with the resistance function on the multimeter. They are all fine. I even replaced the old 15A audio fuse under the hood with the spare 15A. Still nothing. Did the same with the 2-10 A electical parts fuses. Nothing.

I 've been working on this for over a week and been frustrated as I can't find the problem. I noticed the 15A audio fuse only controls the 12V constant and has no effect on the switched power. I checked continuity from the +ve battery terminal to the right side of the audio fuse terminal and it was good. However there is no continuity after the terminal (to ground). The lengths of the leads on the multimeter are not long enough to check continuity back to the 12V wiring harness wire. I've read and many suggest testing fusible links. I know these are under the hood in the fuse box next to the battery but I've never seen one so I don't know what they look like or how to get at them? Do I have to pull the fuse box apart? are they underneath? I see some strange looking larger rated amp fuses in plastic casings (30, 40, 75, 100A). Are these the fusible links?

Sorry for being long winded but thanks for the help. The dealer wants $85/hr to find the problem so I'd rather fix it myself.


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## wickedsr20 (Aug 8, 2002)

You could always take the easy way out and run a fused line from your battery to the radio for the 12v constant. Save the diagnostic fee for some speakers.


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## 2001SentraGXE (May 28, 2006)

Yeah, I've read that on here and actually thought about it. However, I wouldn't want the problem to be a more serious underlying electrical issue that if I end up ignoring and run a fused line becomes more shows up after time. If anyone else has any other suggestions I'm all ears as I've tried just about everything. Could it just be a bad fuse terminal or a bad connection b/w the fuse box and harness? I've eliminated a short since on a constant voltage line that would likely drain the battery? Thanks in advance.


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