I have a 69 XR7 Conv. w/ factory cruise and AC, power brakes. I have never used the cruise in my 20+ years with the car as my turn signal lever with the cruise engage button was broken when I bought the car and I could never muster the courage to buy a replacement for $500+.
I have brake light issues and I'm wondering if this unit might be the culprit- Turn Signals work, tail lights work - Brake lights do not, Rear Hazards do not (front do).
I just replaced the turn signal switch because of other sequential issues which were resolved with the replacement. A short time later the brake lights failed. I have current at the break switch on both sides when applied. I have no current at the sequential box on any line when brakes are pressed. I suppose it is possible the turn signal switch I just put in has a defect. It worked for a week or two if so... Is there a way to test the terminals on the switch to confirm it's working properly?
I have looked everywhere for the brake circuit breaker. I have the whole upper dash and instrument cluster out. I have traced the lines from the brake pedal switch. At no point under the dash do they meet a circuit breaker however...
I heard a contact closure clicking out under the hood by my cruise control unit when I applied the brakes. There is a relay (two actually) hidden underneath the cruise control. One clicks (part# FoMoCo C8ZA-9D737-A) when the brake is applied that looks a little similar to the circuit breaker. I see you have that part here as the brake release relay. Makes sense. Does anyone know how I can test the function of this unit? I don't know where current is supposed to flow, and since I don't use the cruise, I cant tell if it's properly cancelling anything. I'm wondering if this unit has failed, perhaps it presents the same pass through problem as a bad circuit breaker, not letting current back to the tail lights?
The green/white (maybe faded Green/Yellow) line on terminal 4 gets current when the brake is applied. No current passes out Black/Yellow on terminal 2, pin 1 is ground - must be grounded to click.
I'm not sure what the other "relay" next to the cruise cancel unit is for. There is no part number stamped on it, just yellow wire on terminal 1 and a red wire on terminal 3. None of these seem to pass enough current to illuminate a test light at any point. Photos of the parts I'm mentioning are here
https://photos.app.goo.gl/98F8DQhbA6eXhQDY7
Thanks for any help you can offer diagnosing.