mustang interior led

Question for all you LED guru's. I have an 07 mustang. I wanted to change the map lights to blue LED's. Not the lamps, but add through hole LED's. When I first installed them they would not work, I then moved the resistor from the positive side to the negative, that made them work just fine. Since doing this My car electronics are a little screwy. I removed all I did and the same thing. Why would the led work with the resistor on the anode (-) and not the cathode(+)? Thanks, this has been bothering me for 3 days now.

There is no significant reason. It is most likely a bad connection - internal break etc. I presume you are using a single LED with (say) a 470 - 560 Ohm resistor? And that it is connected across the bulb? I'd try with a new LED & Resistor.

Sorry for the lapse in response. They were not "across" the lamp. I used the hot side of the lamp and a common ground that all of the lamps went to. Thanks, I will keep you posted on my finds.

Electrically speaking, that is "across" the lamps - ie, in parallel with them. (Unless I still misunderstand.) But the a single LED across ~12V without a resistor should blow....?!