You will have to check all the door sensors.
On a 1999 GEO Tracker, a bad fuse can cause the headlights and dash lights to blink. A bad voltage regulator or alternator can also cause lights to blink and flicker.
err....American workmanship ?
Check all of your blinker lights. There are two in each tail light, one in each center signal, and one at the corner of each headlight, a total of 8 lights should blink when you have the flashers on. If a bulb is burnt out, it will increase the blink rate. Also, installing LED's in the tail lights will cause the blink rate to increase.
There probably is only one cause for your interior lights to go on when you apply the brakes. There probably are brake light wires and interior wires that have warned together.
Most likely poor wiring.
bad headlight switch.
probably the fuse is blown.
ford van 2013 E250 inide lights wont work
On your light switch there is a dimmer for the dash lights . if you turn it all the way to the left your interior lights should come on , turn it to the left and see if that works otherwise it might be a door switch .
Press dome override button 3 or 4 times till you here a beep to put headlights and interior lights back on auto
Blinking lights on dash and exterior lights may indicate a bad ground wire or a faulty headlight switch. Both would cause those problems.
The dimmer switch when turned just past high, turns on the interior lights. There are switches in the door opening that turns the lights off when the door is closed. Either one of these can cause the lights to stay on if they fail.