Stupid cluster is dimming when I hit the brakes
 

1993 SC300 manual. Does anyone have a suggestion on where to look first on potential source of this issue? I assume this could be a ground problem, but hoping somebody has run into this before and can save me some time troubleshooting.

Do your headlights dim when you hit the breaks too? Check your battery grounds, chassis one can get kinda sketch after all these years. Hopefully it's not an alternator problem. My cluster would slightly dim when I used the turn signal, don't know what I did to solve it or if I saw somewhere that it was kind of the norm. :uh: lol

Also try using the search, I'm sure this has happened to others and it would be quicker to do that than just wait around until someone gives you some suggestions/answers.

Try digging in here, I know O.L.T didn't have the dim cluster problem and it's the 1UZ/Auto but maybe you can use something in here to solve your problem.
http://https://www.clublexus.com/forums/performance-and-maintenance/302959-lol-i-have-a-voltage-issue.html

Normally a sign battery and or your alternator is going bad get them checked.

It's a bad ground on the battery terminal. Inspect INSIDE the terminal, not just the wire going to it. Look into where the wire goes in the terminal for corrosion. When the lights din it shows a lack of POSITIVE, not negative, in the electrical system he whole car is a ground so the grounds to the body in the harness would be sufficient for the cluster) due to a bad ground on the negative of the battery causing a positive battery voltage potential issue.

Electrons flow from the ground to the battery. If the battery has all protons it biases itself positive due to lack of ground. If the lighting, which has grounds in the harness, are dimming they are low on protons, have plenty of electrons. It's visualizing itself as low battery voltage, but it's really just low battery potential because the battery isn't receiving enough electrons. Inspect that ground on the battery and to the frame DAMN GOOD on the terminal, inside the post clamp, and inside the wire itself.

This situation is slightly different from a bad ground because while a bad ground is causing it, you have plenty of ground to the lighting. THere is a possibility a bad alt and or battery can mimmick these symptoms, but by the electrical flow chart you do this first.

Great input, thanks for the help. I'll come back on what I find when I get a little time to spend with it.