Master cylinder wiring harness?

[crowmeyocks]

The three prong pigtails coming out of the master cylinder—what does this do? Trying to see if I have an electrical issue worth troubleshooting here.

 

[crowmeyocks]

Anyone know?

 

[DaveBen]

It is probably the stop light switch wiring.

 

[snicklas]

That’s the cruise kill switch that’s part of the recall. The one that likes to burn trucks to the ground.

 

[ifrythings]

The only 3 prong switch would be the low fluid level sensor, you can test this by removing the cap and using something to push down the float in the reservoir.

If you unplug the switch the e-brake light won’t light up when the ebrake is depressed, the low fluid switch is also a jumper.

 

[jrollf]

That’s the cruise kill switch that’s part of the recall. The one that likes to burn trucks to the ground.

This switch is a pressure switch that is inline in one of the brake lines near the frame rail and the driver's floor board. At least that is where it is on my 1993.

1993 F350 Crew Cab Dually
XLT
7.3 Factory IDIT w/Banks Sidewinder
5spd Manual