Docking lights resistor?

[robertglines1]

noticed on my docking lights there appears to be two resistors inside housing. What do they do? bulbs are 12 volt. But all other lighting on the coach is 12v also. They do come on when turn signals are activated on that side.  had one missing and replacement from Bosch doesn't have them:do I need them?   Bob

[eddiepotts]

Bob, check your voltage. I know mine are 24v. I use a resistor on my license plat light so I can use an easy to find 12v light. Someone may have installed easy to find lights.

[stevet903]

Bob - I think those are about a 1 ohm resistor wired in series with the light.  I'm guessing, but I think the intention is for it to be a current limiting resistor.  When an incandescent light is turned on, the filament is cold and almost a dead short.  There is a short spike of current that can be many times the steady state current until the filament heats up and the resistance increases.   The resistor in the circuit limits the current during the start up spike - they could have done this to be able to use a smaller circuit breaker or to keep it from tripping when the light is turned on.  I'd keep it....

Steve

[robertglines1]

the replacement doesn't have the two resistors so think I will go to elect supply house and get a couple.makes sense about sudden load..there are 4 of them on coach 55 watt each. you can turn all 4 on for parking or two come on when you put on turn signal for cornering.  sort of neat when backing in a camp spot at night.Bob

[PP]

"sort of neat when backing in a camp spot at night.Bob"
BUS BLING