Rockford Fosgate POWER 250x2 problem

[chemhaz]

Hi all, I've got a problem with my RF 250x2, I just got it back from my repairer, installed it and it worked welll for about 5 minutes, then all of a sudden there was a constant buzzz from my speakers... however the speakers are run off a Phoenix Gold ZX450.

Here are the symptoms, had a Kicker ZX240 running the subs, no issues then I installed the RF to run the subs, all seemed well then this constant buzz when the lights are on, I turn the lights off and the buzz disappears, so I then turn the engine off and the lights back on..... the buzz comes back, its it's not engine/alternator whine becase I reved the engine with no effect on the noise. I unhook the remote from the RF, same problem, I unhook the RCA's from the RF and the PG stops buzzing. I tried a lot of different scenarios to troubleshoot but the only think that worked was to fully disconnect the RF,

I've now put the Kicker back in to run the subs, and there is no buzz however, I really want my RF 250x2 back in. It was at the repairers because I accidently connected in reverse polarity after one of my many mix and match sessions.

Any assistance will be appreciated, thank you.
I know I'll need to take it back, but would anyone here know what's causing the problem?

[Pano]

You fixed this, right? Just pop a quick note here to tell us what you found. Thanx!

[Perry Babin]

With nothing connected to the 250x2, what is the resistance from the RCA shield on the amp to the ground terminal on the amp?