BrianG

I need some troubleshooting ideas before I commit to big $$$$$.

I own a 1997 F-150, Extended Cab, 4.6L (280cu in), 168,000kM (104,000 miles). After market accessories include CD deck and a electric boat loader.

I recently noticed significant static through the AM radio. Tuning the radio to the low end at 530 makes it more obvious. Use of electrical accessories is very audible: blinkers, flashers, electric windows, etc. I can also hear a noise that I can associate with acceleration. Alternator?

Radio reception on the AM band is bad in areas where previously it was not a problem. Otherwise, I might not be aware of anything wrong!

Ignition wires, sparks, and speed sensor have been replaced this year.

I've had someone hold the antenna to ground it to see if it a faulty antenna, but no change. Valid test?

Any suggestions?

B.

Heathd

what do you mean by hold? I know that sounds like a dumb question, but a proper ground is metal to metal, so if they were just holding it with their hand, it would be a valid test.

wde3477

Antenna unplugged or not seated securely into radio, antenna coax cable damaged, incorrect spark plugs and/or ignition cables used, radio and any amps not grounded properly (typically specified to be grounded to the same point?), excessive solar activity (usually see news blips about communications problems) are some things that come to mind.

BrianG

Thanks all for replies!

I assume you mean it would not be a valid test. Good point. Maybe holding the antenna and touching exposed metal elsewhere on the truck.

The sparks and ignition wires were replaced by an automotive business - for 19 yrs - that continues to be voted best in the city (Langley - Pop ~ 100K). The owner owned this same model for a few years - 1997 F-150. Sooo.....99% sure sparks and wires are okay.

B.

BrianG

I've had a mechanic check the Alternator, rectifier, diodes, battery etc. No problem detected. He cleaned the battery terminals just in case too. Still have the whirring noise through the radio and all the clicks and buzzes associated with using accessories: blinkers, windows, dome lights, brakes, etc.

Sooo...next step is to have a radio expert check the radio. Radio is stock, except there is an aftermarket CD deck on it.

Bit of a relief because I do not want a electrical failure on a fish out!

B.

Ty

I would say that you have the wrong kind of spark plugs, I know if you want to use a communicator on a snowmobile you have to be able to get a special set of resistor (right?!?!) spark plugs so you don't hear the plugs firing over the radio.

I know that most trucks I have driven if you tune to an am station where there is no signal, you will hear all of the electrical pops and clicks. for that mater, every time I turn on my directional, or turn my lights on or off my swr meter on my CB radio will jump.

finally, I know that am stations come in better when there is dense cloud cover, and poorly when it is a bright clear day.

terrydwaters

I have the very same issues with my AM radio reception that began suddenly and recently with no changes in the vehicle. I suspect we've both developed bad grounding somewhere but don't know where the grounding straps are located.

terrydwaters

OK, I fixed the problem. It was the ground strap that runs from the intake manifold bolt to the firewall just to the left of the air intake. I loosened the bolt holding the strap to the firewall and re-tightened it to scrape a better connection and all that extra noise went away.

While I was at it I cleaned the contacts of the ground strap from the cab to the frame located just under the passenger door several inches behind the front wheel.

I can listen to AM with the engine running again!

Terry
97 XLT 5.4 Tow pkg

BrianG

Terry!!!!

Thanks! I'll check it out on the weekend. Have a few days already prioritized.

I'll let you know.

B.

terrydwaters

By air intake I mean the center of the intake manifold. Probably a better description of it's location would be on the firewall directly back from the oil fill cap.

I drove around today and could clearly listen to a favorite AM station I haven't been able to hear since the problem started.

Good luck.