And the fuel gage reads normal, it goes up when filled, and goes down with use.
The warning light stays on 100%.

The Light has a foil path to the Anti Slosh Module.

Is this part available from ford, or generally good from junk yard / ebay.

1999 Ranger XLT 4.0

 

I'd try removing, then re-installing the slosh module first, to see if that clears it. They are available off of ebay for around 35 bucks. I bought one, as my gas gauge was completely inoperable. Then I purchased a new (used) Explorer (white backround gauges) cluster, and it had a working slosh module in it. I removed this cluster however and went back to the original cluster, because half of the dash lights did not work in the Explorer cluster ($%#@!)!

PM me if you are interested in my spare slosh module.