Replace HU-850 with Aftermarket HU

njohnson10 · Post by **njohnson10** » 04 Dec 2012, 18:13

Hi everyone,
I apologize in advance if I have somehow missed this answer. Or if I've found the answer, but have been intellectually unable to make sense of it.

Background: I have a 2005 V70 2.5T with the factory HU-850 head unit with the amp under the passenger seat. It is the Bose setup with the front speaker. The HU-850 has been glitchy (goes nuts switching between sources every so often) for a while and I have decided to replace it with a Pioneer AVH-P8400HB HU.

Concerns/Questions:
1. Should I bypass the factory amp as Crutchfield recommends?
- If so, do I have to run all new cable all the way to the speakers? Can I run speaker wire from the Pioneer HU to the existing speaker wire connecting into the factory amp? If so, what wires connect to which wires?

2. Should I get one of the ebay Volvo factory amp adapters? Like This One.
- Is there a specific one you'd recommend for my exact setup?

Will the factory amp be as good as the Pioneer unit? I've always loved the way the stereo sounded, just want reliability and more features.

Thanks in advance... I hope I haven't embarrassed myself with my NOOBness.

NJ10

timmyc · Post by **timmyc** » 04 Dec 2012, 18:26

I'm no expert, but I know that you can get an aftermarket harness for the new HU that will plug directly in to the factory plug (You will have to wire it to the new HU). And your new HU should have enough power to run the speakers as they are typically pretty low RMS values. Although, if there are still 8 speakers in the newer cars as there are in the older 850's, you may want the extra punch, I know I would!

Personally I would go with the eBay adapter. Looks simple and straight forward and is apparently made to do just what you are looking to do!

Good luck!

njohnson10 · Post by **njohnson10** » 06 Dec 2012, 08:47

Thanks Timmyc! I'm having to wait for my missing but, "supposed to be in the box" bluetooth mic to be shipped to me(bought the unit "as new" open box for a nice discount), but the BT mic wasn't in the box. I'm still happy the seller made good on support, but I have a bit more time before installation while waiting on the shipment.

I might still take it to a local installer, but for the purpose of this thread I do agree that I think that the aftermarket HU -> factory amp cable will work for this application and I will use it if I do the install myself. I have your information and the ebay seller confirms the cable for the HU850 factory amp setup in the 2005 V70.

Thanks again!
NJ10

njohnson10 · Post by **njohnson10** » 07 Dec 2012, 10:16

More related questions...

The Pioneer has an Orange/White wire that must be connected to the "lighting switch terminal" to be able to dim the unit when the lights are on. The wiring harness I have does not have a place for this connection. The V70 has automatic headlights...

Where should I connect the orange/white wire in order to have the unit dim when the headlights turn on?

Will I have to manually turn the lights "on" to make this work, or will the unit dim when the lights automatically come on?

I'm not very good at reading schematics, any help will be greatly needed/appreciated!

Thanks!
NJ10