Engine won't turn and out of ideas :(

[Intempestivi]

Hoping someone on here can help.

We have a Peugeot 106 and it was working fine one day and simply died the next.

We replaced the solenoid, however, that hasn't fixed it. We noticed that the glow plug light wasn't coming on and have replaced the relay box--the light's still not coming on and the engine is still not turning.

We're wholly out of ideas. We can't bump start it, it's got a new battery, new solenoid and new glowplug relay box. We can't see any fried wiring, however, we have checked and it would appear the glow plugs aren't getting any voltage.

Before all of this started, there was some issues with the turn signals--they would intermittently cut out, but it was overridden by briefly pressing the hazard light button.

I should also note that the engine is trying its absolute hardest to start, it's going "rrr-rrr-rrr" and physically rocking back and forth in its efforts to start.

Can anyone help, please?

Thanks for your time.