Alternator and charge light both not working

What has happened to idle speed since then? Ford engines do normally idle rather high for a long time, especially when you're not used to that. Other brands of that era had an "idle flare-up" to 1500 RPMs at start-up that lasted just a few seconds, then it came down to normal right away unless the engine was real cold. Ford's idle flare-up can last 20 - 30 seconds, and it comes down rather slowly.

GM and Chrysler use the same "stepper" motor to adjust air flow past the throttle blade to control idle speed. Ford uses a different type of voltage-adjustable solenoid to vary the size of that air passage. Carbon build-up in any of those systems can cause idle speed problems, With Ford's solenoid, the plunger is spring-loaded to return to a lower speed. If you find idle speed is wrong and doesn't change very much as the engine warms up, that assembly may have carbon build-up inside it. Idle speed should drop very low if you unplug that solenoid while the engine is running That would show if it is working or not.

As a side note, temperature sensors have extremely little problems because there's just one component inside them. The one notable exception was Ford's coolant temperature sensors from the early to mid '90s. I actually saw one for myself where its resistance would bounce all over the place while the ohm meter was solidly connected with a pair of small jumper wires. The engine's idle speed varied widely all over the place, and you could see the coolant temperature bounce all over on a scanner. This was on a former student's car, then we learned later that this was a real common problem. The fix was a new sensor, and it was an easy diagnosis once you knew what to look for.

If you think a vacuum leak is the cause for high idle speed, use a hose pinch-off pliers to pinch various vacuum hoses as close to the intake manifold as possible. If that lowers idle speed, move further down that hose until you come to a "tee" or spice, then block each one to figure out which one to follow. There will be the correct vacuum hose routing diagram on the emissions sticker under the hood for your engine. That will show all the hoses so you don't overlook any.

We have better experts for transmission problems, but you need to start a new question for that, otherwise they will not get to see what you posted or have a chance to reply. The new question will also get cataloged in such a way that others researching the same topic can find it and perhaps be helped by the solution.

Here's the link to post a new question, if you need it:

https://www.2carpros.com/questions/new

Very happy that you solved the charging problem. Please keep me updated on your progress.

Here's everything I found related to the transmission.