1978 Johnson 4HP outboards Service Manual, Page 39Get this manual
eTo test for shorts to ground, calibrate the ohmmeter to high ohm scaleConnect the black meter lead (-) to the armature plate (ground)Attach the red meter lead (+) to the "C" terminal jumper wire in the connectorSee Figure 4-16Any needle movement indicates the sensor coil or leads are shorted to groundA shorte, sensor must be replaced, or the grounded lead repaired to remove the shorted condition _ 8
bInsert jumper wire to terminal "0" in the armature plate end of the connectorSee Figure 4-17cTo test the resistance, connect an ohmmeter (calibrated to high ohm scale) between the two jumper wiresThe charge coil resistance is good if the needle indicates 575 75 ohmsSee Figure 4-17dTo test for shorts to ground, calibrate the ohmmeter to high ohm scaleConnect the black meter lead (-) to the armature plate (ground)Attach the red meter lead (+) to the "A" terminal jumper wire in the connectorSee Figure 4-18Any needle movement indicates the charge coil must be replaced, or the grounded lead repaired to remove the shorted conditione00 not remove the jumper wires from the connector, and continue the troubleshooting procedure 83073