Wiring Harnesses?

[marffeus 10+ year member]

I was wondering if it would be damaging to my radio unit to just reuse an old wire harness from a previous radio.

My old radio was a Premier DEH-P840MP and the new one will be a P880PRS, and since they're both pioneer I figure connection's will be the same and instead of paying for a new install I could just use this old wire harness.

Thanks for any input.

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[Prowler573 5,000+ posts]

As long as they use the same type of harness (and I will assume that Pioneer hasn't made any drastic changes to it in 3 or 4 years since the 840 was new) then it will not be a problem at all.

My current HU is attached using the harness that was provided new with the HU that was two installs before it (I had a KDC-X569 then upgraded to a KDC-X679 using the same installed harness and now my XXV-01D is on that same harness still //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif)

 

[maldecido33 10+ year member]

don't

 

[KaeZoo 10+ year member]

Pioneer actually has changed harnesses in the past few years, but if it's the wrong harness, it just won't fit into the plug. If it fits, the pinout should be correct.

 

[Prowler573 5,000+ posts]

don't

Why not? It certainly works fine for me. If there is already a harness wired in place that is the exact same as the one supplied with the new unit assuming that all the wires in the older harness are intact why wouldn't you use it rather than removing it and rewiring an exact replica in its place (which is a real waste of labor in my opinion) ?

 

[marffeus 10+ year member]

OK sounds good. One question though, my last system had alternator whine and I never did find anyone who could fix the problem //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif

I was wondering if a poor installation of the wiring harness can lead to any kind of noise in your system. The ground on the harness I have already hooked up is attached to bare metal so I am pretty sure that the ground on the harness is not the issue.

At my local shop they did say "wow, it's a mess back there (in reference to behind my head unit)"

I don't know a whole lot about the installation so I am not really sure what they meant but they clearly said they didn't want to mess with it. Deep down I'm hoping the whine was caused from bad grounding within the head unit it self (something older pioneer units have been known to have). If I still have whine once the P880PRS is installed then I will be pretty pissed.

 

[marffeus 10+ year member]

OK, well I've been looking more into the wiring configuration that the installer did years ago.

Something I found odd is that my stock radio harness is still in tact! All but 2 red wires are cut, but I don't see why they would of left my OEM harness in tact. I guess in case I ever wanted to go back stock or something.

Is this bad to have the old harness with 2 (red) wires still connected sitting out in the open behind my head unit?

Also, is using the factory ground a bad idea? I recall reading somewhere that it might not be a good idea to use factory head unit grounds.

 

[KaeZoo 10+ year member]

If it hasn't been a problem so far, it won't likely be a problem now.

Factory grounds are usually okay.