Battery open short damage

**Steve-S** · 09-25-2016, 06:56 AM

I was using a lithium ion battery which open shorted during operation . I replaced the rectifier and the battery back to a regular lead/acid type and all was fine for a little while . Now I have a "no crank , no start" and the trim does not function . The battery voltage is 13.2vdc . The motor is a 2011 20hp 4stroke Merc w/ a 4000 gen 2 remote control box . I can't remember if there is a OEM fuse inside the control box or not . I had also contemplated if the switch box was damaged . But , does the switch box relate to the starter and the tilt function ? All other electrical is operational . When the ignition switch is turned to the on postion I have power from the control out (turns on instrumention) , if the fuse in the box blew I figure it would not power the instruments ? If the ignition is turned to "on" I can bypass the the starter relay at the motor and the starter cranks . It seems I'm going to have to open the control box trace the current through the components ...PITA for sure .

Any insight would be apreciated .

Steve

**pointer** · 09-25-2016, 08:12 AM

Not up on the 20 4 Stroke, but am 95% sure there is no fuse in the controls.
There is usually a fuse under the cowling that if blown will cause loss of start and trim.
I can't say for sure if the key on will power the dash with it blown.
If you have the owners manual check to see about that fuse.
If you have a trim sender, check the wires to the sender.

pointer

**Steve-S** · 09-25-2016, 09:32 AM

I had pulled the fuses under the cowl and visually inspected . There are two fuses ; one on top of the rectifier and one just aft of the starter relay . Visual inspection , they all looked good held up to the sun light . I decided to start over , this time I used my Power Probe 4 tester (I highly recommend ; these are wonderful). I found no contenunity on the fuse at the starter relay . I replaced it and problem solved !

In 30 plus years of repairing electrical this is the first time I have come across this ... The fuse looks fine but suffered a failure . It was odd that this was intermitant before failing . Even with a magnifying glass I can see no signs of failure , odd ...

Thanks for your input Pointer .
I'm off to the lake ,
Steve

**j_martin** · 09-25-2016, 08:16 PM

Originally Posted by Steve-S

I had pulled the fuses under the cowl and visually inspected . There are two fuses ; one on top of the rectifier and one just aft of the starter relay . Visual inspection , they all looked good held up to the sun light . I decided to start over , this time I used my Power Probe 4 tester (I highly recommend ; these are wonderful). I found no contenunity on the fuse at the starter relay . I replaced it and problem solved !

In 30 plus years of repairing electrical this is the first time I have come across this ... The fuse looks fine but suffered a failure . It was odd that this was intermitant before failing . Even with a magnifying glass I can see no signs of failure , odd ...

Thanks for your input Pointer .
I'm off to the lake ,
Steve

A fuse can easily fail from a mechanical crack. If it is lightly loaded, it won't cause any of the burning or melting impressions we are all used to seeing. It can easily be intermittent as well.