Easy way to check Ignition Coils

[Recreational_Anxiety]

I was working on the bike the other night and I thought of a much easier way to check the ignition coil resistance (as the coils tend to be a pain in the ass to get at without removing the tank).  All you need to remove is the seat and the left fairing (rear); and of course you'll need a multimeter of some kind.   Below are a couple of pictures I took with the bike apart (you can do this with the tank still on the bike):

Note:  My bike is a '93, so I'm assuming the wiring will be the same for pre 2001 models.

Locate the large wiring harness beside the ignitor unit (black box).  There are 4 wires that go into it (Black/Yellow, Orange/White, White, Black/White)



It's the one located right in the middle of all the connectors in this picture:


You can either disconnect the harness or just probe the back of the connectors to get your readings (use the lower half of the connector for all the tests):

If you disconnect the harness, insert your multimeter probes into the slots that correspond to the correct wire comming out of the back:



This photo shows the probes in the proper location to check the primary winding of the left ignition coil:



This photo shows the probes in the proper location to check the primary winding of the right ignition coil:



You can also stick your multimeter probes into the back of the connector to the corresponding wire:




+==========================================================================================+
|                  | Expected   |               Wires to Measure Between                   |
|                  | Resistance +-------------------------+--------------------------------+
|                  | (in Ohms)  |   LEFT IGNITION COIL    |    RIGHT IGNITION COIL         |
+==========================================================================================+
|  Primary Winding |  3 to 6    | White & Orange/White    | Black/Yellow & Orange/White    |
+------------------+------------+-------------------------+--------------------------------+
|Secondary Winding | 18K to 30K | White & Spark Plug Wire | Black/Yellow & Spark Plug Wire |
+==========================================================================================+


This photo shows testing the secondary winding in the right coil:



This photo shows testing the primary winding in the right coil:



If you find that your resistance is excessive for any of these tests you can then check resistances directly at the coil to discount problems in any of the wires going to the ignitor box.

[KJB (10/15/07): Re-aligned the chart]