FM Radio Noise
 

Slightly different problem to the chap with the AM noise problems... I get a crackle on FM signals. Its 'random' but constant. Doesn't seem to be engine speed related and isn't the high pitched whine from ignition leakage.

I've checked the antenna and its within the specs in the books for resistance etc.

It does seem to reduce in level when the engine is on coast or overrun.

Not apparent when listening to CDs.

The vehicle wiring has been modified to fit ISO connectors rather than Ford's own and the Head Unit was fine when it was in the Land Rover.

I'm going to try some ferrite chokes and electrolytic capacitors to see if it attenuates it.

Any ideas?

Being that its a crackle and not something constant that can be associated with engine/ignition noise, I'd be checking connections ant the rear of the unit. Can't remember right now but I know there is a power feed for the OEM radio illumination that I never used on the aftermarket unit. If its connected to something or grounding to the radio casing you could "hear" that through the system. Its a long shot though. You'd most likely have blown the dashboard illumination fuse by now if that was the case.

Thanks Joe, I will check the wiring as I found a half disconnected connector hanging down the back of the dash from when the monkeys in CA fitted the JVC head unit that came with it so maybe there is something shorting or my crimp terminals are bad.

Simon