No hazard voltage

[Vic Butler]

I've double checked the wiring diagram for the late rubber bumper B's and the flasher relay is fed from the direction indicator switch by a light green wire with a brown trace. A green wire runs from the relay to the hazard warning switch. The light green wire with a brown trace runs to the hazard flasher unit. A brown wire from there runs to the starter solenoid and in this wire is an inline fuse . If this is fitted to yours then that could be the problem. I've asked for my other workshop manual back but I think the early rubber bumper cars had this inline fuse and it's in the engine bay near the fuse block.
I missed this on my first look at the diagram.
Edit. I checked on my MG and the inline fuse with the brown wires is right under the starter relay. It's in a white plastic holder which unplugs at one end.
I did a check and with the fuse removed the indicators work but not the hazards. With the fuse replaced the hazards worked too.
Apologies for the mix up but I misunderstood your first post about the brown wire from the starter relay because there's also a brown wire from the starter relay to the main fuse block on the diagram I used

[Tom Brearley]

Things may be different for US cars, but the inline fuse was located behind the centre console when hazards were first fitted as standard here.

[waltmgb]

The turn signal issue has been resolved. Bad switch. Right turn works intermittently while jiggling switch, left not at all. I will check behind the console to see if the fuse is there. As the picture somewhat shows there is no fuse below the starter relay. And all the fuses in the block are good, voltage where it's supposed to be on both sides. Thinking about running a new wire with fuse to the hazard flasher. If, as the wiring diagram shows, the original was one wire with no other connections from the starter relay through a fuse to the flasher then bypassing with the same circuitry should be fine.

[Vic Butler]

Try spraying the switch with electrical switch cleaner.

[Not_Anumber]

I went through the pain with the indicators on my 1979 BGT a year or so ago. I found I had two faults. the first was a faulty indicator flasher unit. I replaced both flasher units with new electronic ones that are not load dependent. (That way I can change to LED bulbs at any point in the future). I remember they needed an extra earth / ground wire running to them.

I then discovered a second fault that turned out to be caused by dirty contacts within the hazard switch. It took a few checks of the circuit diagram to work that one out as it wasnt otherwise obvious the path for the normal indicator function runs through part of the hazard switch. It proved easy enough to open and clean as they are quite robust inside. Just dont let anything drop out and get lost on the floor.

[Vic Butler]

I've had the same problem with the hazard switch. It was down to corrosion on the H shaped contacts inside iand it's dead easy to strip down. I removed mine from the dash using a very thin screwdriver to prise it out gently.
Another candidate for switch cleaner.