Toyota 08 headlight earth

[Willybb]

My right headlight and high beam is dim. I’ve changed the globe and also changed the headlight plug. Problem still exists. From reading up the most common cause of this is a poor earth connection. After following the earth wire from the headlight it just joins up with the main harness and isnt earthed on the car body close to the headlight. It appears to enter into the car interior with the rest of the harness. Can some body help me with where it may be earthed? 
The left hand side headlight works fine and there seems to be no other electrical issues anywhere I’m aware of.

Edited July 22, 2021 by Willybb
Additions

[Hiro]

It's pretty typical for headlights to actually be earthed through the combination switch, which is why the wires would be going back in to the cabin

[campbeam]

On 7/22/2021 at 8:16 PM, Hiro said:

It's pretty typical for headlights to actually be earthed through the combination switch, which is why the wires would be going back in to the cabin

I recall another post from a Hilux owner where he cleaned the earth connection which may have been a grounding point for the wiring harness inside the cabin. 

[Willybb]

On 7/22/2021 at 6:16 PM, Hiro said:

It's pretty typical for headlights to actually be earthed through the combination switch, which is why the wires would be going back in to the cabin

Okay thanks mate. So this would involve removing the steering wheel to access the earth point on the combination switch. Is this the only access?

Edited July 25, 2021 by Willybb
Fixed

[Hiro]

On 7/25/2021 at 7:49 PM, Willybb said:

Okay thanks mate. So this would involve removing the steering wheel to access the earth point on the combination switch. Is this the only access?

The earth point may not be on the steering wheel itself, but checking the combination switch pins would be the first port of call.  Try and get a copy of the wiring diagram for your car to work out exactly where the earths will be in the circuit