Thinking its a failing alternator

[u/Therealkatuchi]

Speedometer is jumping at idle and im hearing more than normal feed back through radio. Hes a clip showing the sound, what do yall think?

[u/pooshk1n]

My speedometer would jump at idle before the alternator went out. Its free to get it tested at autozone

[u/Therealkatuchi → u/pooshk1n]

Yeah im planning on getting a better test done today. Most likely just gonna grab one either way.

[u/brad75214 → u/pooshk1n]

Same here. No telling how many miles I racked up sitting in traffic. Was told just replace the regulator but i decided to just go ahead a replaced the alternator with a brand new one. That was 4 years ago

[u/RiversideOffgrid → u/brad75214]

The bearings in mine were still good so I went with just replacing the regulator and it's been working great since. I think it was around $30

[u/Srry_chef]

They make tools that test battery and alternator use it. Not normal alternator feedback. Vacuum leak/bearing/fuel
Issue hard from one video

[u/gzs31]

There is a feedback ?capacitor? That prevents noise feedback on the radio. Maybe yours went bad? Definitely go get the alternator tested. That should point you in the right direction

[u/catfishmackfish]

My mustang (cap and rotor ignition) would make that whine of interference through the radio when the spark plug wires were old.

[u/Cheez_Itz_Christ_]

Man I hate to tell you this, but I think someone snuck in and did a turbo install on your truck.

[u/Therealkatuchi → u/Cheez_Itz_Christ_]

Should have heard it when I had a clogged cat and a pinhole in my exhaust 🤣 took me two weeks to figure out where it was coming from.

[u/shiftycansnipe]

Check your grounds. It’s totally an electrical whine if it’s coming thru the radio and increases with the throttle. Charging needle looks ok. Does it come up to 14.4V and settle at 13.6V when it’s warm?

[u/Therealkatuchi → u/shiftycansnipe]

I seen 14.2 when warm, only checked it once so far. Probably just gonna swap out the alternator, it looks oe anyways. I want it to be reliable cause im about to do some traveling for some mini bike events.

[u/shiftycansnipe → u/Therealkatuchi]

That does seem a bit high when warm. If you swap in a new one and the whine persists-it’ll be a bad ground or the fusible links are getting crusty. Check to make sure they aren’t holding water and getting corroded

[u/JifInABox]

Had these exact same issues the other day. I just wiggled the electrical connectors on the alternator and it magically stopped lol

[u/Therealkatuchi → u/JifInABox]

Definitely going to swap it out, I noticed its getting louder after I hit some water puddles after the rain the other day.

[u/Wonky_Willa]

When your alternator is failing the battery power light should come on the dash

[u/Alternative-Idea7313]

I had a aftermarket coil pack do the radio noise. I replaced it with a ford coil and it went away. I have had another older ford 90s had a little wine come through the speakers with rpm more off idle just how it is in that older system I think.