Transmission mechanical or electrical
 

1996 F150 XL SB 302. Drove the truck to the store with no problems. Got in, started it, stereo speakers would not work. Started driving and the gears would not shift. Pulled over, turned it off, restarted and speakers started working and gears shifted normally. This all happened during a heavy rain.

drive it some more and see if it does it anymore. if it does keep doing it then we will look more into possible causes

Now it is idling high and the transmission is making a whining noise.

it's starting to sound like a PCM issue

We had the transmission filter and fluid change in November, less than 2 months ago. We specifically asked that they make sure the fluid level was right. We ended up having to put a 1/4 quart of transmission fluid in. We have checked for leaks and have found none. I drove it several places this afternoon and it is running fine, and the gears are now shifting as smooth as butter. My 19 year old learned a valuable lesson about fluid levels today.

So, you are telling us that 1 cup low on transmission fluid caused your stereo speakers to not work intermittently, along with the sloppy shifting? You may not have seen the end of your sporadic rough shifting / speaker issues. The root cause is likely not yet found and probably not related to this very minor difference in transmission fluid level.

i was thinking the same. how in the hell can low transmission fluid cause malfunction in the speakers? lol

This is the only thing that will cause BOTH symptoms:

https://www.supermotors.net/getfile/...ail/07done.jpg
(phone app link)

LOL, that is what I said, and the truck ran great, until today! Now it is revving up without pressing the gas, and it is changing gears without pressing the gas. I was soooo wrong on this. I was hopeful that the speakers and the transmission were just a fluke that happened at the same time. Is the revving engine causing the problem with the gear shifting? This time, the speakers continued to work, but the gears were shifting all wrong. Turned if off, waited a minute, then it ran fan for a little while and it all started again. High revving and weird gear shifting.