ignition coil wiring

[olsluggo]

I have a 4 cyl.GM 181 engine with a external resistor between the coil and the distributer.I had a new engine block and wiring harness installed.My manual and new wiring harness both show the purple and purple&yellow wire going to the plus side of the coil.Neither diagram shows the resistor or where it is supposed to be wired to.The dealer had the purple wires attached to the resistor and not the coil.Can anyone help me.Thanks.

 

[rbezdon]

Re: ignition coil wiring

Cant tell you with a lot more specifics on the exact ignition type and coil etc. You didnt even post a year and since the engine was changed I am not sure if that is relevent any more. If they changed the block why did they change the wiring harness and ignition??<br /><br />For some clues see the posting I just put on the 5.7 electrical problems driving me crazy posting just below yours.

 

[olsluggo]

Re: ignition coil wiring

The boat is a 1972 Thunderbird.The engine went bad in 1996,hole in the cylinder wall.New block installed,made in Mexico,Mercruiser,with point ignition ,coil and resistor.I had the wiring harness changed,steering to rack steering so everything would be new.Head,manifold ,carb.distributer etc.were transfeered to new block.

 

[hoot]

Re: ignition coil wiring

sluggo, i have an older engine also (1978). i am confused on your resistor location. my resistor is in line from the key switch to the coil + post. it is a wire. based on your info, possibly this will help. the purple wire might be the resistor wire from the key. the purple/yellow might come from the starter solenoid and be on the + post also. do you have something between the coil and distributor? is it possible that you have a wire resistor and a ceramic kind also. can you check the volts at the + coil post with the key in the on position, not starting.

 

[rbezdon]

Re: ignition coil wiring

hoot - for the key on test to show anything you need to get the coil + volts with key on, no start with point open and points closed. This can be simulated by checking the coil + volts, if 12 points are open so coil - can be shorted to ground to simulate loints closed. With points close coil + should be in the range of half of what it was with the points open.

 

[Dunaruna]

Re: ignition coil wiring

 

[olsluggo]

Re: ignition coil wiring

Thanks for the info.I finally found a wiring diagram for the coil.The purple wire and the purple & yellow wire go to the ceramic resistor and the resistor wire goes to the plus side of the coil.

 

[fendersfender]

Re: ignition coil wiring

now im confused..i have twins in my boat ('85 searay with twin 3.8L omc) i never knew what that "white block" was with the purple wires attached to it...........BUT only 1 of the motors has it.........??????????????

 

[rbezdon]

Re: ignition coil wiring

white block is likely the ballast resistor and necessary for point type ignition with point type coils. The setup depends on your specific ignition set up and there is no garantee you have the stock set up. Also, are you sure the entire ignition setup is the same on both engines including the specific coil part number?? If not then I would assume some one has done some "repair". If your are not running a hot coil or burning points you are most likely OK.