Static Cracking Noise from Speakers - 1998 Ranger - Ignition off

[sahasranshu]

Hello Enthusiasts,
I became owner of a 1998 Ford Ranger 2.5L RWD with 93K miles last week. It was a one owner vehicle which wasn't driven much and sitting on the owner's backyard. When I purchased this truck, the owner mentioned about a intermittent static noise from speakers even with ignition and keys off and this apparently drains the battery too. To tackle this owner had installed a kill switch on battery and taken off the fuse from the Radio.

Today when I put the radio fuse back, I heard the static cracking noise even with the ignition off and no keys.

What could be the reason for this? and how shall I troubleshoot/resolve?

The radio works fine when the vehicle is running so I think Radio is good and it has something to do with electrical connection wires.

Secondly, I read on a forum that sometimes the cigarette lighter is the culprit which drains the battery and keeps drawing current to a stage where it melts. Co-incidentally the driver side cigarette lighter is not present in my vehicle.

Requesting members for help. Thank you all for your time.

 

[pjtoledo]

on both AM and FM bands?
does it respond to the volume control?
factory radio?
have rodents been chewing on wires while it was sitting in a yard?
try grounding the radio case.

frayed wires under the dash? try wiggling all the wires or smacking the dash.

with hearing the noise with the key off, check where the radio is getting power from. if it's not factory stuff.

 

[sahasranshu]

Thanks for your suggestions. The matter is now resolved. It was the broken cigarette lighter and positive/negative terminals shorting the circuit which was causing the issue.

Although the truck was sitting in a yard the wires underneath the dash look good. I am yet to check the wiring in the engine bay though.

It was stock radio with cassette player, but I found another stock radio with CD player from local junkyard and ended up swapping it. I took off the broken cigarette lighter and swapped it with another 12V socket.

So now my truck has two 12V sockets instead of one 12V socket and one cigarette lighter.

Lastly, I am yet to do a parasite current draw test to check if there is any current leakage.

Anything else that you would recommend checking if all wiring is good?

The engine bay has lot of wasp nests which I have to clean as well