Karl Townsend wrote:
I bought a brake controller that uses a sensor in the brake line. Today, I
took the brake line apart at the master cylinder, installed the "T" and
sensor. Had my better half pump the brakes while I bled. No big deal, I
thought.

Well, as soon as I started the truck, the brake warning light came on. So I
had the better half pump the brakes while I bled a whole can through the
front wheels. No joy.

I called "the Kid". He said to get a vacuum device from bumper bumper for
only $20. Well, it was $50. But I got it and bled a can through each front
wheel. No sign of bubbles at all. Note: the sensor is on the front set on
the tandem brakes

Still no joy. I got a brake warning light. I just got ****ed and called it a
day. What do I do tomorrow?

Karl

Karl, hazy recollection of this on earlier Fords.
Should be a block on the left fenderwell area with brake lines, 2 in (F
& R) and two out (ditto).
Little capped boss top center, with a wire sticking out. When the
differential gets upset, the sliding valve in the center of that block
moves to one end or the other, and turns on the light.
IIRC, you have to center that piston, leave a tool in there to hold
the piston centered. Bleed the lines, then then reinstall the sensor.
Light should be off then, good to go.

I have a 1996 F350, but it's not where I can look at it right now.
Besides, it has ABS. Not sure your 1993 does. But that may not make a
difference WRT to above procedure, as I think the ABS they used was a
downstream setup.