illumination lights only getting 6 volts..

[modulation]

When I turn my interior lights on the illumination lights are very dim.This includes the cluster lights/AC lights and lights on my all my buttons.

When I check them with a volt-a-meter they are only getting 6v instead of 12..

Yes I've messed with the dimmer switch and tried to turn it up to it's brightest setting but it doesn't so anything.

I've replaced my dimmer switch with another and same thing..I've done all the checks in the FSM for illumination lights and it says I should replace my TCU.

But before I run off to the junkyard I thought I'd post and ask if anyone has ever had this problem.

When I unplug my dimmer switch and leave it unplugged the lights are still very dim (nothing changes.) What does your car do if you unplug the dimmer?

Anyone think that a bad TCU could cause this?