View Full Version : Ignition Coil with points - yellow wire disconnected?


1st 67 SS/RS
Oct 30th, 07, 05:45 AM
I have what looks like a stock points and stock coil. I have replaced the distributor cap and rotor with a new stock looking Accel cap and rotor kit (brass connectors). I purchased a MSD Blaster 2 coil to replace the current one along with new Accel race wires and NGK XR5 plugs. The engine was and still is running fine with the new cap and rotor. My question before switching coils, is that the coil has the one wire on the - and the original resistor wire (white cloth covering) running to the +. The yellow wire from the wiring harness has been cut and is just hanging by the firewall. I have read that it goes to the starter R terminal to give the coil full voltage. Can the coil operate with points and the yellow wire disconnected? Should I use the wire with the new coil? I am going to track the other end of the yellow wire to the starter and make sure that it is still connected. This engine was replaced by the PO and I have fixed a few shortcuts that they did. What are some of the problems or drawbacks that occur from the yellow wire being disconnected? Thanks for the advice.

MLL
Oct 30th, 07, 06:07 AM
The yellow wire "bypasses" the resistor wire so you have more voltage going to the coil when the solenoid/starter are engaged. When the solenoid engages it sends battery voltage to the + term. of the coil. Since the starter motor turning over the engine puts a high load on the battery dragging the voltage down some, having only the resistor wire going to the coil and dropping the coil voltage even more can make for a weak spark and make the car harder to get started. The ONLY time the yellow wire comes into play is when the solenoid is engaged when starting so it would have no effect once running. The only problem that you'd have with it disconnected is a weaker spark when starting up which may make it a little harder to get it going.

1st 67 SS/RS
Oct 30th, 07, 06:50 AM
Thanks, that's the answer I was looking for. It does take a little while to get the car started if it sits over night. If it has been running it cranks up fine. I appreciate the help.