On my "75 4x4 I just replaced all the gauge cluster bulbs and the "Brake" light and "Low Fuel Economy" lights are always on. Where is the switch to activate the brake light? I do not see it on the e-brake pedal assembly. I was also curious how the fuel economy light was activated/deactivated. Is it something in the factory carb? I have an Edelbrock carb and was interested to see if this was causing it to stay on. Thanks guys.

 

The brake light is only tied into the switch at the proportioning valve, has nothing to do with the park brake. That didn't start until the mid 80's.
The low fuel economy light is likely just triggered from low/no vacuum. I bet there is a sensor somewhere that once had a vacuum hose attached to it, that no longer does.....

 

The low fuel economy light was a '75 only option. It was activated by a firewall mounted switch.
When manifold vacuum dropped below a certain point, the light came on to indicate low fuel economy.