Any Idears?

On my 70 the brake warning lamp was there..

Andrew

 

My 73 has the same plug in the hole.

 

My Fairway Green '73 CJ-5 (back in 1973) had one too. Fairway Green is one of my favorite Jeep colors.

I suspect it's vestigal from the brake warning light. I recall we've discussed this before - and the '72 has a light there, but Jeep moved the warning light to the cluster for '73. Goes along with the other dash and instrument changes for 1973 (chrome bezels, new knobs, heater controls, etc.)

Might work well for tachometer cables, if you mount the tach on the column. My '73 had a column mounted tach, but I brought the wires up (in some heavy spaghetti tubing) with the turn signal harness.

How are your heater controls doing, Steve?

 

What is the "brake warning light"?

 

I don't seem to have that plug, or a brake warning light on my '72 dash. Makes me start to question how close to original my dash is.

 

I believe the brake warning light indicates if you have a problem with fluid loss. There is a switch that is normally "centered" (for lack of a better term) on the distribution valve and when it goes off center due to fluid loss in either the front or the rear, the light that is wired to the switch indicates a problem.

 

Here you can see it in the 1974 sales brochure.

 

If i'm correct the Brake warning lamp light to tell you that hand brake is apply....

 

yup or the fluid is gone...

 

Multifunctional, IIRC.

 

I can't swear on this particular year of CJ but on most vehicles the red dash mounted brake light serves two functions. One to alert the driver the park brake is engaged, and two to let the driver know of a loss of fluid pressure or low fluid level.

The switch referred to above is called a pressure differential switch. It has a shuttle valve in the middle that is hourglass shaped with a switch mounted so the plunger extends into the narrow part of the hourglass. The hourglass shaped valve is mounted horizontally typically. The front hydraulic system is on one side of the valve and the rear hydraulic system on the other side. Loss of pressure on one side allows the pressure on the opposite side to push the valve towards the system with low pressure. This closes the electrical switch completing the ground circuit turning on the dash warning light. On late model vehicles with ABS this will also typically turn on the amber ABS warning light and disabling the ABS system, but I digress.

The switch that turns on the red warning light for the park brake is typically mounted to the pedal assembly and is a simple grounding circuit switch (momentary contact).

 

IIRC, my '75 also has the plug in the dash. I'd have to double-check to be sure, though.

 

My '70 has a hole in the same place. I'm sure it was original, as it has a little notch at the top of the hole for indexing whatever was supposed to be there (IDK if they used that brake light in 70).

 

My 75 has it and as timgr commented I used it to route the tach wiring...

http://i259.photobucket.com/albums/hh307/mofus22/tach.jpg

Mike