Circuit Breaker keeps popping on 1983 Chrysler 90 hp outboard

[kcsguide]

I have a 1983 Chrysler 90 hp outboard Model# 906R3D, SN: 1003. I don't know anything about its history but when I turn the key to the on position, a circuit breaker pops. The breaker is located between the starter relay and the rectifier. I know the starter works as I jumped across the starter relay and it engaged. I replaced the rectifier with a new one but the CB still pops when I turn on the key. The ignition switch is new and I'm fairly sure that I wired it correctly as I used a Clymer shop manual that had the wiring diagram. Could the breaker be bad? A short somewhere? Any Ideas would be appreciated. Thanks

 

[jerryjerry05]

What to do: Start unhooking everything at the fuse panel, one by one.
Then the same on the motor.

 

[Frank Acampora]

Does it have Motorola ignition with the finned black box and distributor or prestolite ignition with two CD boxes mounted on a plate? Is it a three cylinder 90 or a four cylinder 90?

 

[kcsguide]

It's a 4 cyl 90. Prestolite ignition.

 

[Frank Acampora]

OK! The prestolite is/was a self energizing ignition, completely separate from the battery electrical system. THUS: we can eliminate it as a source of the problem. Now, if the short occurs only when you turn the key to the run position --that is, it is immediate and does not need to have the key turned to start-- then there are several places to look. First disconnect the wire at the "A" or "I" terminal of the switch. This wire supplies power to the dash gauges and accessories. (usually) If this solves the problem, then look for a short in these devices.

If this does not solve the problem, or if the problem occurs only during start position, then look at the starting circuit. Check the two yellow wires to and from the neutral interlock switch for shorts. Jump the solenoid from battery terminal to yellow. if the breaker pops, then the solenoid is internally shorted OR the yellow wire is incorrectly attached to the terminal with the black ground wire..

Incidentally, your 90 was originally rated as a 105. When the NMMA mandated that ALL outboard engines should be standardized by rating horsepower at the prop, Chrysler simply down-rated the 105 to a 90. Thus, we can assume that for this type lower unit, gear losses and water pump power absorbed amounts to about 15 horsepower.

 

[kcsguide]

I disconnected the wire frim the I terminal and problem solved! The rest should be pretty straight forward. Thank you for the help.