72 johnson 125 shorting out

[rickdog67emtp]

I noticed when I left ma bettery hooked up, it died. Continuity test revealed 325 ohm between + and powerhead. Any suggestions?

 

[rickdog67emtp]

Re: 72 johnson 125 shorting out

PS Is coastal marine lower unit oil the proper lube for my lower unit? http://www.coastalunilube.com/heavy/marine.htm

 

[Joe Reeves]

Re: 72 johnson 125 shorting out

Rick... You will always get a reading between the battery and the positive cable if you're using a ohm meter.<br /><br />Remove the main positive cable and all other cables from the positive battery terminal. Make sure the key is in the OFF position. Hook up a VOLT meter between the battery positive terminal and the cables that normally connect to that positive cable. Have the volt meter set to the lowest reading posible.<br /><br />Any voltage drain will register, showing in volts what amount of drain is present. From that point on, it's a matter of elimination... disconnecting items while watching the meter.

 

[rickdog67emtp]

Re: 72 johnson 125 shorting out

I unhooked the stator/rectifier diode assenbly (#1, #3, and the remaining purple green wire at terminal 10). The short went away. The stator checked within limits with ohm meter, but Im not sure what the other component is exactly. Book says either a clipper circuit or rectifier/diode. It is some type of assembly sealed in a type of liquid electrical tape or epoxy. It has a yellow wire at #1, yellow/gray at #3, and purple/green at #10. Im assuming this is the prob. It doesnt have any type of metal case for a ground like the book says, just some type of component covered in this glue/epoxy that hangs by the wires. This may be causing the problem I have with the intermittent ignition fire I posted earlier that went away again. Any suggestions?

 

[Joe Reeves]

Re: 72 johnson 125 shorting out

Rick.... If that component isn't surrounded by a metal case, but is rather an expoxy glob, it's a shift diode.<br /><br />A clipper circuit and also a rectifier has a surrounding metal case.<br /><br />You can test that shift diode with an ohm meter. <br /><br />1st Test - With the RED ohm meter lead connected to the "Purple/Green", touch the Black ohm meter lead to the "Yellow" wire, then to the "Yellow/Gray" wire.<br /><br />2nd Test - Now, reverse the connection by having the Black ohm meter lead connected to the "Purple/Green" wire, then touch the Red lead to the Yellow wire, then to the Yellow/Gray wire.<br /><br />You should get a reading with one test but not the other. Any deviation from this such as a reading in both directions, or no reading in either direction (on any wire) indicates the diode is faulty.

 

[rickdog67emtp]

Re: 72 johnson 125 shorting out

I have now narrowed it down to either the rectifier or the clipper/diode part I described earlier. Ihave no way to test the unknown part,the manual says I need a known good one, I havent got one to go by(manual also stated either clipper is grounded are has a ground wire, mine has neither). On the rectifier, the yellow and red have absolute continuity both ways, contintuity one way between yellows and ground are around .690 m ohms.

 

[rickdog67emtp]

Re: 72 johnson 125 shorting out

sorry joe, didnt see youre reply...thanks

 

[rickdog67emtp]

Re: 72 johnson 125 shorting out

shift diode tested good. one way on each circuit was .390 and .387 m ohm. however, no continuity between the yel and yel/blue either way.

 

[rickdog67emtp]

Re: 72 johnson 125 shorting out

yel/blue is yel/gray, sorry

 

[rickdog67emtp]

Re: 72 johnson 125 shorting out

The shift diode doesnt have anything to do with shorting + and -, does it? When I hook the battery up, it sparks with or without harness hooked up.

 

[rickdog67emtp]

Re: 72 johnson 125 shorting out

Any other thoughts? Thanks so far for the replies!

 

[rickdog67emtp]

Re: 72 johnson 125 shorting out

I unhooked each one as per joe. Stator isnt it. either shift diode or rectifier, either unhooked stopped the short.

 

[rickdog67emtp]

Re: 72 johnson 125 shorting out

I have replaced the rectifier with no short now( and charging), except now, after running for appr. 1 min., motor just cut off. Its doing the same thing as it has been doing sporadically. No power to coil. No spark when sensor wires jumped. Any way to repair pulse pack? ( I'm almost dead set on this ford electronic ignition though )I just got to find out how much it draws. I also thought about goin points route. What should I do?