Originally Posted by Pilot
Thanks for the input sleepyboy I have found out through Crutchfield whom I purchased the amp from that due to the Head unit in the 2013 foco that this amp the GM-D8604 may not be compatible due to a constant data signal coming from the computor. The amp has an auto turn on through the RCA plugs that were supplied with the amp for splicing into the line level speaker wires the head unit has no rca output only line level speaker wireing. As far as the amp turning on even Ford is confused why this should happen when a door or even the hood is opened. I think but dont hold me too it that it is a function of the computor warning system when a door or the hood is unlatched that shows on the information screen. Talk about the twilite zone Ha Ha.
I have an lc2i(lineout converter) that has the same signal sensing turn on. It powers on both my amps but I don't get that pop. Powers on whenever i open the doors etc.
Do you get the same pop when you turn on the HU with the car "off"?
And I don't want to question your install but your your HU doesn't have a direct connection to the speakers right? like you cut/disconnected the speaker wire, then soldered a new speaker wire from the headunit-side speaker wire to the amp? Not just piggybacking the signal from the speaker wire.
When you mentioned the OEM HU has line level input...did you mean speaker level output(which I believe are High level)? I'm assuming you are using the high level input connector on your amp?
Try connecting disconnecting the speakers from the amp and connect the oem speaker if it still happens. If its ok, then check your speaker install. If not then its probably the amp. Another thing is high level inputs aren't the best and you may what to try using a line out converter to convert the headunit output signal to line level.