Brake Switch Adjustment

I am swapping in a dual diaphragm brake booster from a 95 XJ into my 90 XJ without ABS. I'll post some pics but basically I got a switch on the push rod itself and a switch above it. I did not put any spacers between the booster and firewall as I saw others have done.

So what is the function of the second switch? And how are they adjusted? I got the lights to come on but intermittently. I cut the hole in the push rod larger to the size of the old one and I cut the flat spot on the end.

BTT

Hmm either goes to the TCU, to enable, disable torque converter lock up IIRC, or it is to the crusie control. One is the one you asked about, the other is way up above, higher in the dash but also attached to the brake peddle hardware. I forget which is which.

The white switch up top is for the trans computer to unlock the t/c. Should have a vac line to it as well if you have cruise control.

lawsoncl said:

The white switch up top is for the trans computer to unlock the t/c. Should have a vac line to it as well if you have cruise control.

Click to expand...

So back to OPs question, what is the second set of wires on the brake switch itself for?

On the brake switch, one connector is for the cruise control, and the second is for the brake lights. The vac line way up top is supposed to be the backup method of ensuring the cruise disengages. It's tee'd off the vac line that goes to the cruise vacumn servo and breaks the vacuum when the pedal is pushed.

I think that fuse dangling in the foreground is the inline fuse for the cruise control. Looking at the 88 FSM wiring diagram, it shows the power to the stalk switch is fed from the brake switch, through the inline fuse to the stalk.

That makes sense that the second one up top is for cruise control, but that is the one with the adjustment. And also I noticed on the 95 that I took the booster from that it doesn't have the one on the push rod the closer one, just the one up top only without the vacume line.

So how is close one adjusted? Or is it adjustable?