On my bj7 the blinker will work for about 30 seconds, then not at all, any ideas the cause of this issue?
A couple of things to try first.
Remove all the connections into the brake switch over riding relay on the inner wing on the car - one by one and clean up the terminals, use some petroleum jelly or similar when replacing the wires. If you feel capable remove the lid of the unite and clean up the contacts with some fine 'Wet and Dry' paper - used dry, blow any dust away.
Check all the bulbs and their connections, especially the ground wires, including the indicator light in the dash.
If that does not sort the problem then go to the flasher unit itself, you may have to get a replacement one. There is a test outlined in the workshop manual if you have one -
Check that terminal B is a battery voltage with respect to earth using a voltmeter
connect the flasher unit terminals B or (X) and L then operate the direction indicator switch - if the flasher lamps light and stay lit then the flasher unit is defective. If the lamps do not light then there are more tests to do on the brake override relay.
Temporarily link relay terminal 1 to terminals 2 & 3 - left lamps should flash -
Temporarily link relay terminal 1 to terminals 6 & 7 - right lamps should flash
If the lights do flash under this test then there is something wrong with the brake switch over riding relay.
Clean and check all connections first though - this could be the cause.
Bob