Blown fuse 20amp fuse would could be the issue?

[gregbones777]

J88mslccc 1988 88hp spl Johnson. I just recently put some new parts on the motor. I put a new power pack on, a newer used stator, a new rectifier, and a new battery. I cleaned up the connectors on the wires to the battery. I can get the motor to crank and start up, but sometimes the fuse will blow. It’s happened to me twice now. The fuse is located in the red rubber boot in the picture that’s attached to the solenoid. Any ideas on how to trouble shoot this issue or what I can look for?​

 

[Crosbyman]

the fuse also feeds accessories and power trim relays

remove or at least turn off all accessories asa start and retry with engine alone

if OK bad accessory if simply turned OFF if still not OK could be accessory wiring shorting out B+ ...even if they are switched off... power wire to accessory may be shorting to ground

check under dash and recent work areas

possible bad accessory if fuse blows only when accessory itself is turned ON

inspect all wires carrying +12 for chaffing or grounding especialy if it blow as you turn the engine left or right ..... check harness wires


see basic wire diagram

https://maxrules.com/graphics/omc/wiring/88_89_88_110.jpg

 

[gregbones777]

the fuse also feeds accessories and power trim relays

remove or at least turn off all accessories asa start and retry with engine alone

if OK bad accessory if simply turned OFF if still not OK could be accessory wiring shorting out B+ ...even if they are switched off... power wire to accessory may be shorting to ground

check under dash and recent work areas

possible bad accessory if fuse blows only when accessory itself is turned ON

inspect all wires carrying +12 for chaffing or grounding especialy if it blow as you turn the engine left or right ..... check harness wires


see basic wire diagram

https://maxrules.com/graphics/omc/wiring/88_89_88_110.jpg

Okay thanks for the diagram! No power trim so the only other accessories I can think of would be the primer solenoid or the tachometer. The lights and everything are attached to there own power supply
With a on off switch.

 

[gregbones777]

So there is a couple things I’m gonna look into. That had had the vro disconnected at one point in its life but the wire is just hanging out still with a bullet connector on the end so I’m gonna cap that off. The next thing is looking at the diagram that was provided to me, my wiring on the terminal board does not match what I’m seeing in the diagram. So I’m gonna switch some wires around to Match the diagram and see if that helps my fuse issue.

 

[Crosbyman]

IF YOU ARE NOT FAMILIAR WITH ELECTRICAL CIRCUITS I SUGGEST YOU GET ASSISTANCE ....MOVING WIRES AROUND AS A TEST CAN BE VERY $$$$$ IF THINGS START SMOKING .

it is always best to REMOVE things which are possible low resistance loads or intermittent grounded wires ... start with a close inspections

a 12v -10 amp fuse would blow if the suspect load is less than 1.2 ohms or less than 2.4 ohms measured to ground for a 12v - 20 amp fuse. so look for a low resistance path to ground on the fuse output .

 

[gregbones777]

IF YOU ARE NOT FAMILIAR WITH ELECTRICAL CIRCUITS I SUGGEST YOU GET ASSISTANCE ....MOVING WIRES AROUND AS A TEST CAN BE VERY $$$$$ IF THINGS START SMOKING .

it is always best to REMOVE things which are possible low resistance loads or intermittent grounded wires ... start with a close inspections

a 12v -10 amp fuse would blow if the suspect load is less than 1.2 ohms or less than 2.4 ohms measured to ground for a 12v - 20 amp fuse. so look for a low resistance path to ground on the fuse output .

But my wires don’t match what is on the wiring diagram you provided so I’m just moving the wires to match the wiring diagram. My rectifier red wire is hooked on the same block that the red solenoid wire is hooked onto, But on the diagram it is showing those two wires in separate spots on the terminal board.

 

[Crosbyman]

the terminal strip has a link to connect both wires ... the rectifier RED output MUST reach the solenoid main B+12v from the battery post to backfeed charging current to the battery ...


if your wires are in fact together on the same strip bolt that is OK anyway ...that is what the link would do anyway.

again... I suggest you do not move thing around to much $$$$