I recently converted my '95 Lumina radio from the stock incandescent bulbs to LED's. This is not a simple task!! The bulbs are laid out in a number of parallel arrays in such a way that resistance must be calculated for each of the individual arrays. Then the location of the resistor must be determined for each of the arrays in place of the existing jumper wire. If anyone would like some help doing this, send me a private message and we'll talk. Should be relatively the same for procedure for AM/FM, AM/FM/cassette and AM/FM/CD; Blazer, Camaro, Caprice, Cavalier, Impala, Malibu, Monte Carlo, S10, Sonoma, some others. (saxonmor)
Addendum: I found out that the procedure is NOT the same for the AM/FM/Cassette as it is the OEM CD player; the circuit board is a different layout and I had to retrace all of the circuit paths prior to replacing the jumper wires with resistors and installing the LED's.
