The PRNDL dim or not lighting at all is usually a problem with solder joints on the seven SMT resistors to the Left of the cluster plug.
The traces and pads are fairly thin and they will easily delaminate from the circuit board if you use too much heat.
If you don't have a decent temperature controlled soldering iron and some experience with repairs like this then I'd farm this one out.
Look up the user behind the jeffescortlx YouTube channel. Instrument clusters are his thing. If I didn't do my own electronics repairs I'd contact him.
Here's one of his fixit videos...
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1959 M35A2 LDT465-1D SOLD
1967 Dodge W200 B383, NP420/NP201 SOLD
1969 Dodge Polara 500 B383, A833 SOLD
1972 Ford F250 FE390, NP435/NP205 SOLD
1976 Chevy K20, 6.5L, NV4500/NP208 SOLD
1986 M1008 CUCV SOLD
2000 GMC C2500, TD6.5L, NV4500
2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263
2009 Impala SS LS4 V8
RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials...
Please include at least the year and model in your threads. It'll be easier to answer your questions.
And please let us know if and how your repairs were successful.