wiring question.

[lime73]

what under the hood has 12v with key in on position and also while cranking?  reason i ask is i am wiring MSD box and cleaning up unnecessary wiring and need a constant 12v signal even while cranking for box.   Thanks in advance for your help.   

[mopar12372]

the msd is very finiky. make sure it has its own circuit . if you are not useing the ac that circuit is perfect . some times there are fuse openings with only the hot on one side check your fuse box for blank spaces and check the jot run with key switch , do it with a volt meter to make sure your getting the correct voltage in the circuit your working with.

[Chryco Psycho]

You will have a dark blue run 12v & a brown wire 12v cranking at the ballast resister , connect them together to the red trigger wire for the MSD

[lime73]

Thanks Chryco worked like a charm...   LIGHT EM UP BOYS !!!!!!!!!!

[Chryco Psycho]

 

[Kevin71]

Chryco
Are you talking about wiring all three together.  I take it this will illminate the balast resistor.  I have 2 wires coming in and 2 wires going out of my ballast resistor.  What do I do with the other 2 wires?

[dodj]

Chryco
Are you talking about wiring all three together.  I take it this will illminate the balast resistor. 

Yes it does. The MSD does not require the resistor.

[Chryco Psycho]

Exactly , wire the Blue , Brown & red MSD trigger wire together , the other two wire out of the Ballast power the ECU which is replaced by the MSD & the coil feed which is also eliminated as the coil is fired by the MSD , so the ballast goes bye bye too