Rear lights low voltage

[Mr-C]

I seem to have a weird lighting problem. I kept getting rear left bulb failures coming up. So looking at the bulb it was on but very dimly then would flicker and go out. I swapped to a new bulb and same again. I checked the other side and noticed that the bulb was dim. I checked the voltage and on the rear lights I am only getting circa 9.5v but checking other sockets on the same clusters I'm getting closer to 12v!

The lights that are in the tail gate are working fine

HELP!

 

[hades-]

the holder may be ****** I just had to fit one to my daughters car as bulbs were dim

 

[Mr-C]

the holder may be ****** I just had to fit one to my daughters car as bulbs were dim

We that was my thoughts but to be honest the cluster circuits looks fine

 

[hades-]

they did on here
I cleaned them etc and as a last chance I tried a friends and it worked so bought one.