No spark without hotwire, 80-280SL

[meltedpanda]

helping another MB guy , only way to get spark is running a hot wire to the coil,then motor runs fine, fuel system is fine.
I am thinking coil or ICU, I think there is a way to check the ICU but I cant find the link? I think that may be the issue , could it be coil? What about block resistors?

as always all ideas welcome

[Tomguy]

Are you saying you need to hotwire the (+) to the coil or the (-)? Usually the (+) is constant to the coil when the ignition is on (someone correct me if I am wrong please), so it could be a blown fuse or a bad wire and/or connection to the coil.

[meltedpanda]

Sorry out of town. Positive to make it run

[meltedpanda]

Can anyone give me the connections to the two ballast resistors. The from and to?

[pop & blow]

hot wire comes from the switch wire from the ignition , then to ballist resister and then to the POS side of the coil. has to come from the switch for power usually a purple wire with white stripe, check and make sure it works only with the switch on.

[meltedpanda]

thanks , so perhaps this circuit is bad or could the coil or ICU be bad as well . Ways to eliminate??
I have read where others had this issue but the thread just stops before resolve is noted

[have mercy]

Originally Posted by meltedpanda

thanks , so perhaps this circuit is bad or could the coil or ICU be bad as well . Ways to eliminate??
I have read where others had this issue but the thread just stops before resolve is noted

The way it looks to me res. blocks lower the voltage , so the points do not have 12 volts, this is to make the points last longer,I have 2-3 complete withthe wires/res. still attached that I removed will send pic if needed.

[meltedpanda]

would love to have picture