SC-901 Radio case earth?

Post by **scot850** » 08 Mar 2016, 23:01

I recently fitted a USA SPEC PA-11VOL ipod/phone adapter with AUX input to my son's 06 XC70. I wrote about it on the P2 section.

I now plan to do the same on my P80 SC-901 head unit but using a USA SPEC PA-HON unit. There are only 2 wiring connections required (other than swapping out the 6CD changer cable to the one for this unit) and one of those wires is an earth. On the HU head unit for my son's car there is actually an earth screw on the rear of the casing.

My question (as a non-electrical person) is, is there a similar screw I can use on the rear of the SC-901 head unit? I've added a picture of the rear of the head unit below, so how would I know if I can use any of the screws on the rear?

: Rear of SC-901 Head unit

Appreciate any guidance on this.

I have an option on a used unit as I refuse to buy a full priced one when the manufacturer is not sure if it works with a Volvo Head SC-XXX unit with multi-CD changer built in. They have already told me the one for my son's car worked for SC-XXX head units but it doesn't. So having already bought one on their advice I don't plan to buy another until they can confirm it will work, although at the price I may take a chance to further our knowledge for anyone else who may want to add these features in. I'll let you know how it works out.

Neil.

Post by **Ozark Lee** » 09 Mar 2016, 08:23

As far as I know all of the Volvo headunits have chassis ground whether it is marked or not. An actual wire being run to the chassis is not necessary, however, since there is also a ground wire in the harness. If you do have a ground wire that needs a place to go any screw will work but some of the screws often have a corresponding nut on the inside of the radio to hold things like a heat sink or a connector shell.

...Lee

Post by **scot850** » 09 Mar 2016, 10:22

Thanks Lee, I will check on one of my spare units by pulling the top cover. I am aware of the ground wire in the harness, but I have heard some people who fitted these units complaining of noise when using the ground wire itself. When I fitted the unit to my sons 06 XC70 it had no issues with static noise or interference so that was why I wanted to use the radio unit earth knowing it is well earthed through the unit itself.

Neil.

Post by **BEJinFbk** » 09 Mar 2016, 13:59

I'd recommend going with power and ground off of the harness.
Keep it all on the car side of the connector. Much easier for popping
the radio out if you need to work on it or the dash. Keep it simple.

Post by **scot850** » 09 Mar 2016, 14:36

A good point! Hadn't thought about that as I have no plans to re-move the 06 XC70 head unit anytime soon, it was ok to use the head unit earth, although for all the time to remove one screw? Mind you, I do have a harness for another recently liberated amp that the clown who removed the radio at Pnp cut the connector off. I have planned to re-attaché the connector (which I found in the back of the car!!) so it would be easy to splice in the wires and not waste damaging a good harness (as you may know they are obsolete now).

Hm, seems like more investigation is falling at my feet. I'll update how it all works out for all to see!

Thanks,

Neil.