1985 140 hp Johnson - Tach is not working

[Bobby D.]

I looked at my Seloc manual on how to check the rectifier it sounded simple, maybe a little too simple. I removed a black box held in place by 3 bolts. It has one ground wire and five wires with plug in connectors on the ends. The numbers on the side of the sealed unit are CD4/8L 582530 OA 9T 24. Is this the power pact, rectifier or something else. I have an ohm meter. Can I check this unit? If so, how? There is no change in battery voltage at rest or with the motor running. Thanks

 

[wilde1j]

Re: 1985 140 hp Johnson - Tach is not working

The regulator/rectifier is water cooled. The piece you describe sounds like a powerpack. Do you have a shop manual? If not, I would suggest getting one (OEM is the only one worth owning). If the tach is not working, chances are the regulator/rectifier is bad and or the stator. The stator may be checked by measuring the AC voltage to the rr. Not sure of the value, but it needs to be something a least 18 to 20 + VAC. If you have voltage from the stator and the DC voltage across the battery terminals is not at least 13.5 to 14.5 VDC with the motor running, you need a new rr. Do NOT run motor with any leads disconnected and never remove leads from battery terminals with the motor running.<br />Good luck.