I have a 06 Roush that the instrument cluster gauges are dim but but radio time display and all other non Roush dash lights work perfectly and work as should when you use dial to dim and brighten. The white backing on Roush gauges seem like they don’t light at all! The red u see in photos do dim and brighten. See photo of them at full strength. Fuses are fine, was thinking headlight rheostat but lights do dim and brighten turning ****. Anyone else have this problem.

 

 

Unless somehow the Forum operation and access is causing your problem ..................
You are in the wrong section. You need to post questions about your Mustang in the proper section. There is section just for the S197 (2005-14) Mustang. Someone with mod powers in this section will have to move your post to the correct section.

Welcome new member, please take time to learn how the forum structure is set up

 

Moved to tech.

 

I think something on the gauge cluster itself is bad since the needles do light, and that comes through the same cable assembly. You could pull and test the gauge cluster to find out is a single LED is blown or if a circuit trace fried, but it may be a better option to pick up a used GT cluster off ebay with a similar mileage (or pay them extra to program the mileage accurately). When you get that you will need to pull the needles and remove the cluster applique sticker and put the Roush applique sticker on the replacement. I would tend to put it in without the applique sticker first just to make sure it is in working order then replace the needles and applique.

You could send it to Roush for service/replacement, but I'm guessing that would not be covered under warranty anymore.