The fact that oem harness was cut is where I would start. You can have a short on the negative side of the speaker channel and a multi meter will still show continuity. You can also have a positive from one channel and a negative from another channel mixed. This will cause static. A polarity test will not tell you this.
I would strongly recommend going back in and getting rid of the butt connectors for solder and heat shrink. As someone who has been in car audio for years and is very familiar with both Ford F-150 amplified and non amplified systems, you need to determine with certainty that your connections are solid and correct.
Please describe your signal chain in detail. From headunit to speaker.
I would strongly recommend going back in and getting rid of the butt connectors for solder and heat shrink. As someone who has been in car audio for years and is very familiar with both Ford F-150 amplified and non amplified systems, you need to determine with certainty that your connections are solid and correct.
Please describe your signal chain in detail. From headunit to speaker.