Canned Benz
Member
After three years of ownership I think I've finally got to the bottom of why I keep having to change my dizzy cap, rotor arm and points every year. When looking into ignition coil upgrades I realised that my w114 280CE has been fitted with a Bosch blue coil. The blue coil is a 12v coil with an internal ballast resistor. My car has two external ballast resistors designed for a 9v coil. So I've been giving my 12v ignition coil a 9v feed resulting in a weak spark causing the points, cap and rotor to burn out.
Rather than doing away with the ballast resistors I've decided to order a Bosch red coil, which is a 9v coil designed to use external ballast resistors. I've read the red coil should have 1.8 ohms of ballast resistance. My car is currently fitted with two 0.4 ohm ballast resistors, the ones with a blue clamp.
My question is are these resistors connected in series? In which case do I need two 0.9 ohm ballast resistors (the ones with the gold clamp)? Or are they for two different purposes? In which case do I need one 1.8 ohm ballast resistor (the one with the red clamp) for the coil and to leave one of the 0.4 ohm resistors where it is?
Sorry it's long winded. Any help would be much appreciated. I think anyone with experience of an m110 fitted with D-jetronic could be able to help.
Rather than doing away with the ballast resistors I've decided to order a Bosch red coil, which is a 9v coil designed to use external ballast resistors. I've read the red coil should have 1.8 ohms of ballast resistance. My car is currently fitted with two 0.4 ohm ballast resistors, the ones with a blue clamp.
My question is are these resistors connected in series? In which case do I need two 0.9 ohm ballast resistors (the ones with the gold clamp)? Or are they for two different purposes? In which case do I need one 1.8 ohm ballast resistor (the one with the red clamp) for the coil and to leave one of the 0.4 ohm resistors where it is?
Sorry it's long winded. Any help would be much appreciated. I think anyone with experience of an m110 fitted with D-jetronic could be able to help.