Interior Switch Identification

[Skitzo]

My buddy has a 71 and I have a 72 and we can't for the life of us figure out what the hell these switches and/or lights are on the drivers side. I'm sure you guys can clue us in and I hope I don't feel dumb when I find out, .



Thanks much

[69rangerf100]

the one on the lower dash is the brake light and the other is a safety light

[BobbyFord]

The one in the door jamb is the ambient sensor for the TRS system.

[69rangerf100]

dumb question what is the TRS system i have never heard of that

[BobbyFord]

Transmission Regulated Spark control. http://www.fordification.com/tech/image ... /trs04.jpg

[Skitzo]

Brake light? Is that a low brake warning light or something? Wow, so weird I was just looking at the TRS system wondering what the hell it was. Killed two birds with one stone on that one, but I have a question about the TRS system (thread steer). Is the vacuum line going to the carb from that part #12A170 constant or does it go to the timed port? As of now on mine it's to the timed port on my truck and that doesn't seem right. I'm going to slap on a new BG Demon Jr. carb to it and I'm wondering about that vacuum line. Thanks guys, this forum is so much help!

[fordman]

the brake warnign light is for a brake fluid imbalnce in the brake fluid system. if the brakes ever go low in either the front or the rear the brake block will trip to one side. and the system will be imbablanced. so the light will come on to tell you the fluid is imbalanced.

[sargentrs]

the brake warnign light is for a brake fluid imbalnce in the brake fluid system. if the brakes ever go low in either the front or the rear the brake block will trip to one side. and the system will be imbablanced. so the light will come on to tell you the fluid is imbalanced.

Please forgive the hijack but, how is that triggered? The PO of my truck put a toggle switch in that hole for some reason I have yet to figure out. Nothing's hooked up to it. I always thought he drilled it in there for fog lights or something. It would be nice to hook it up for it's original use. What kind of switch actuates it? Thanks!

We now return you to your previously scheduled programming.........

[70_F100]

There's a switch in the distribution block that trips when the pressure drops in either the front or rear brakes (split system).

[seattle67]

On the frame of the truck, below the master cylinder, is a brake fluid distribution block. It has a differential pressure switch in it that senses a difference in pressure between the front and rear brakes. So if you lose brake pressure, say in the front brakes, it will activate the switch. The switch then sends a ground signal to the lamp on the dash and voilà, you have a light.

[sargentrs]

Cool. Thanks guys! I'll checkthat out.