Re: 1969 Johnson 85 HP Amplifier?
Purple goes to POSITIVE 12 volts, black and white goes under the flywheel to the points, blue goes to the coil, and grey is just a tachometer lead that you can ignore.<br /><br />To test it, connect the blue wire to your coil. I am assuming the coil has remained in place, bolted to the motor and is well-grounded to the motor. Ground the case of the amp well to the motor. If you're mounting the amp on its normal mounting plate on the back of the motor, make sure the plate is well-grounded to the motor with a grounding strap. Make sure all the grounding connections are clean & tight. <br /><br />OK, pull the fat wire from the coil. [This is the fat wire that goes from the coil to under the flywheel.] Find another plug wire somewhere, put one end on the coil and one end near the block (within 1/2 inch). You're going to see if a spark jumps here. <br /><br />Now connect the NEGATIVE pole of a 12V battery to the a good ground on the block, and connect the POSITIVE terminal to the purple wire. I was writing in CAPS because if you do this backwards, you may blow your amp. OK? Now momentarily ground the black-white wire to the block. Every time you touch the black-white wire to the block, you should get a spark at the end of the fat wire.<br /><br />All the OMC points amps interchange (1968-71 55 & 60 hp triples, 1969-72 85hp V4, 1971 100hp V4). They sometimes have different part numbers because the connector styles are slightly different - that's all. The higher hp V4s also had a battery-powered CD system, but it was sensor-triggered, and those boxes won't work. They're shaped differently, so you can tell them apart. <br /><br />I believe the replacement boxes (both OMC and aftermarket) are more robust than the original equipment OMC boxes. I have yet to see a failed replacement box - doesn't mean it doesn't happen. Nonetheless, in order to make sure your's lasts, you need to be sure it's getting good clean power from the battery - no spikes or ripples. This means a big battery, clean terminals & wiring, and clean (no intermitted crappy connections) wiring throughout the hull. The big battery acts to damp out the spikes. Be real careful not to connect the battery backwards (don't let your buddy hook up the battery for you), and do not disconnect the battery while the engine's running.<br /><br />Have fun!
