i am considering removing my HU-850 stereo from my Volvo V70 T5, 06 plate and replacing it with a pioneer avh3200dvd. I have read some forums regarding the removal procedure and one thing keeps coming up -is it necessary to disconnect the negative terminal before staring the remove the unit. i would like some clarification if someone can advise please?

 

You don't have to disconnect the negative terminal to just replace the HU unless you disconnect the climate control module. I just replaced my HU-650 with a Pioneer AVH-4200DVD a couple of days ago. There is enough slack in the CCM cable connection to leave it connected, but on my 06 V70 I had to disconnect it in order to modify the rear of the factory radio housing. Basically, here is what I did.

1. Turn key to position 2 and move gear selector back (to allow room to remove center stack with radio/CCM).
2. Pull center stack out far enough to disconnect radio (leave CCM connected for now).

At this point, I discovered the factory radio housing in the center stack only had cutouts in the back to allow enough room to connect factory connections, so I had to cut out the back with a Dremel tool in order to allow enough room for the connections to the Pioneer.

3. With center stack hanging to the side, put the car back into park and turn off.
4. Wait approx 10min after shutting off key before disconnecting neg battery terminal to allow all systems to store settings.
5. Disconnect CCM after disconnecting neg battery terminal and remove center stack from vehicle.
6. After getting the aftermarket headunit kit installed in the center stack, connect the CCM.
7. Put key in pos 2 before reconnecting neg battery terminal (I read this somewhere in Volvo tech database) in order for all modules to startup properly.
8. Move gear selector back again to allow room to install center stack and connect radio.

If your not aware, your HU-850 uses an external amp under the passenger seat which can be hooked up to your aftermarket headunit using the following adaptor avail on eBay from seller briang9525.
http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEWAX%3AIT

Hope this helps!

 

Wagonman,

thanks alot. It should help. My worry was the disconnection of CCM, which i understand could involve a factory re-set if things go wrong.

The whole removal of this beast is a right dog's dinner, why Volvo designed this in the first place I will never know - probably to avoid replacing their stereos with after sales units.

Out of interest is the Pioneer noticeably better sonically? The connections to ipods, SD cards etc are very convenient but does it sound any better?

 

Mr B,
Yes, the Pioneer is noticeably better sonically. The 7 band EQ really lets you adjust everything nicely. The speakers seemed to come to life after swapping in the Pioneer.

 

looking forward to replacing my stereo now, probably after Christmas. Thanks again for the advice.

 

Another question re: radios. My mechanic says my current one is fried. Anyway to double-check this?
Also, if it is fried, I'm going to just replace it with a regular V-70 radio,cassette,cd player. Any advice on opening up the panel to remove old unit?
I think I understand previous instructions, but not sure about opening up panel to being with.
Thanks c.

 

C,
It's a little different depending on the year. The instructions above apply to 2005+, but getting started on the removal is pretty similiar. The first thing you have to do is remove the trim around the gear selector. Once it's removed, there are two screws at the bottom of the center stack that have to be removed. Once they are out you can pull out the center stack.

 

Since starting this thread i have invested in a Haynes manual

- ISBN_ 978 1 84425 878 9

It has directions in there showing how to remove the gear stick casings etc. It covers the V70 from 2000 - May 2007 and the S80 from 1998 to Feb 2006. the pictures are ok for black and white, but the written instructions make up for any confusion. I also found another good link to an different installation for an IMIV and the starting point is the same:

http://forums.swedespeed.com/showthread.php?128247

The photos here are better. I found this, simply by typing in HU-850 removal into Google.