What are these plugs and yellow box?

[Sam Im Is]

My taillights are not working. I believe its due to lots of extra things being hooked up under the dash and the fuse box being tapped a lot. Any way found some plugs that were not connected and a yellow box and would like to konw what they are. The plugs have a relay on them, then to the right there is a small white plug, to the right of the plug you can see another plug that looks identical to the ones that hook to the brake switch(by the way which plug is one that needs to hook to the switch, i have about 3 and i have cruise control so i have the two prong switch but im removing the cruise and going to the single prong switch. anybody know how many go into the plug and what wire colors.) The other is this yellow box. Says AMC on it (assuming its american motor co. and its factory) Has a low speed ADJ, cetering control and sensitivity adjust. What is this. Also if anyone can shed some light on where the wires should go from the brake pedal switch and fuse they go to on the box would be nice. And if anyone has a fuse box in a 90 XJ laredo or and equivelant of the same they could post a pic of that would be great, mines been tapped a lot. I wanna see whats factory and whats not. sorry the pics are not more clear.

 

[5-90]

Box should be your cruise control "brain box."

The other stuff isn't very clear, and I don't like guessing anyhow on electrical stuff. See if someone local to you can help you go through the stuff, and clean it up (it certainly does LOOK nasty, and I don't think it's all due to the blurry pix...)

5-90

 

[Sam Im Is]

Sooo if im taking out the cruise control its safe to disconnect this box, everything will still run fine correct.

 

[5-90]

Should. I haven't bothered yet, but I've got a couple rigs I've pulled cruise out (underhood) and I can try later...

5-90

 

[Matthew Currie]

When I first got my 87 with factory cruise, it didn't work, and neither did the brake lights. I dimly recall that the setup used two brake switches, and there had been some confusion with the previous owner about which switch connected to what, and also that the wiring was arranged in a way that almost guaranteed that continued use of the brake would unplug the wire if it was routed wrong. You might have to check the brake switch wiring. Otherwise, you can safely yank the cruise control out. I also dimly recall that the cruise control tapped into the fuse panel. It was a sloppy arrangement.

 

[Nevada City Sparky]

Just got through going thru this on my 89, which is the same.

The brake light switch is located at the end of the booster rod on the pedal arm. There are two connectors there, one goes to the brakelights, one goes to the cruise control. Above that, mounted on the bracket that pivots the brake pedal, you'll see a switch that also has a vacuum line going to it. The vacuum line connects to the cruise control servo and works to release pressure when the brakes are applied to disable cruise control. The wires go to the transmission control unit where (I think) it controls the unlocking of the torque converter.

On mine, the lower brake/cruise switch was pretty funky. I replaced with a "normal" style (from a 96 I believe) switch mounted in the hole in the bracket next to the other switch, which is probably usedfor a clutch interlock. I then welded a tab to make brake pedal to activate the switch. Nice and clean and no more funky switch.

Hope that helps.