Specifically need the turn signal circuit. I have no turn or flashers. Wire 55A seems to have a very poor connection when I hit it with the test light. Not sure whats feeding it. It vanishes into a harness into the dash. I have a set of manuals for this truck but the electrical section is crap. Looks like you need an expensive supplement manual for the electrical.
Here is a link for the electrical manual: 99 4000 electrical.pdf drive.google.com
THANK YOU! I googled for an hour last night and was only able to find new manuals!