Later cars have a resistor in parallel whith the bulb, so that if the bulb burns out, current can still flow, BUT that resistor is on the instrument cluster. No cluster, no bulb OR resistor, no current, no battery charge. the problem with the alt light needing to be in line for the alternator to charge--they wired it differently. I think '87-88 cars don't have to worry about that. I wonder if I can do it in my '88?