im hooking up an amp to a factory HU. im using the high level input on the amp. there is an extra wire that says 'signal ground'. it is black and the instructions dont say anything about that wire. do i just ground it? its in the harness with the L and R speaker inputs

 

Who makes this amp and what is it's model number? Does the HU use a common ground for the speaker connections? In other words do the speakers each have their own + wire and a - wire that gets connected to chassis ground? If that's the case you cannot use the amp and HU together.

 

its a crossfire tek752. each speaker has its own + and -. the amp is wired for that but it has an extra signal ground wire just like the line output converters ive seen.

 

I've never seen an LOC that had a signal ground wire like that. All the LOCs I've seen have a + and - wire for power and ground and then the wires for connecting the speaker level inputs and the RCA outputs. I don't see why there would be an additional wire for "signal ground". Hmmm

 

i agree i've never seen that either.
i would call the crossfire tech line as this may be somthing new to their amplifiers.

 

found out by calling the supplier of a LOC. they said its a ground for IF you are picking up engine noise