Electrical Issue?

Hello.

I just installed a new amplifier and subwoofer in my 02 XLT Explorer. Everything is fine when the engine is off. When the engine is on all speakers but the front left are distorted, the sub is fine. I removed the inline fuse to disable the amp but it still turns on with the engine.

Any suggestions? Tips?

Thanks,
Ansy

I would need quite a bit of info to properly diagnose the problem you are having, but some preliminary thoughts are to double-check your connections of power, remote turn-on lead, and ground. For proper connection, you must connect a dedicated power supply cable of sufficient wire gage size for the wattage of your amp or amps, directly to the positive battery terminal with an appropriately rated fuse or circuit-breaker as close to the battery as feasible. The ground cable should be the same gage size and be securely fastened to a good ground (bare metal) on your vehicle. The other terminal of the power connections on your amp should be labeled "rem" or "remote" or "turn-on". This remote terminal should be connected to a switched source of 12-volt power, typically your radio's power antennae lead, or amp turn-on lead, at the back of the stereo, this wire is almost always blue. Once you verify all those are correct, we can tackle the problem of the noise from certain speakers when the engine is running. I'll need to know which inputs you are using on your amps: the speaker-level inputs, or the line-level inputs(RCA type connectors)...

The wire running from the amplifier to the battery, and the ground wire, are both 8guage. About 6 inches from the battery connection is an inline fuse.
The ground wire is running to a metal bolt and post in the rear compartment where the jack is stored.
The third terminal (labeled Remote) is connected to the remote lead behind the head unit, a blue wire.
The amplifier is a mono amp running low-level RCA cables from the head unit's "Sub LR" RCA outputs into the amplifier.

OK, thanks for the info, and hope you didn't feel like I was thinking you were a simpleton or something... Just always have to make sure the basics are done right.
I don't know for sure why the amp would still be coming on when you have removed the fuse, but here's a few things that could be the case: shorted fuse holder; a short to another power wire somewhere downstream of the fuse; Maybe the amp isn't actually turning on and just appears as though it is (Weird design of power indicator circuitry on amp that lights the power-on indicator any time there is 12v present at the remote turn-on lead); circuitry in amp is fried and allowing power to back-feed from remote turn-on lead. I placed those ideas in the order of which would be most likely to least likely.
As for the noise in the output, make sure your signal cables(RCA connectors) are routed as far as feasible away from power wires of any kind, especially the amp's power cable, as they will induce "alternator whine" in the signal from the magnetic field created by power flowing through the wire. Also, make sure each speaker has its own dedicated positive and negative speaker wires running contiguously between the amp and speaker (no grounding of negative speaker wires or using a common negative terminal on amp, each one must have its own positive AND negative.)
Hope this information is helpful to you, but if you still have issues after checking these things, feel free to post back another reply and try to be as specific about your problem as possible, i.e. what any noise sounds like, whether all of your speakers are powered by an amp, or you have some of them running off the stereo head-unit and some on amp.

Don't worry, no offense was taken!

While having lunch today I hypothesized that power must be constantly coming into the REM connection somehow, and sending too a current back to the head unit which then distorted the door speakers. I thought this was happening either from behind the head unit or at the terminal on the amplifier. I knew that I used heat-shrink tubing on the connection behind the head unit and there were no loose wires, so I revisited the terminal at the amp. Thanks to shining daylight (it's been very dark, cloudy, and snowy these last few days) I discovered that I had loose copper way extending from the REM sleeve and it was making contact with the Power/Battery terminal!

I then disconnected everything, refitted all terminal connections so that there were no loose wires and voila - everything works like a charm! The car speakers are also functioning as they should.

Silly me, I should've had no loose wires from the get go.

I sincerely thank you for your assistance 4WDriver, I really appreciate it!

Happy to help, glad you got it working right. I'm a firm believer in the concept that everyone deserves to have quality audio reproduction when jammin' their favorite tunes! :-D