1971 100HP Johnson Electric Shift Problem

[cbkellogg]

The neutral and reverse solenoids to my lower unit have no resistance (0 ohms on the VOM). I have the proper 12V signals from the shift switch. The lower unit shifted fine last year. However. I did have to put the spare lower unit on last year when the original stopped shifting. At that time I did not spend a lot of time to find out why the original quit. Now I chect both lower units and in both cases, both solenoids have no resistance.<br /><br />Before I go to a lot of trouble to find new solenoids, I would like to know what condidtions could cause these solenoids to short out.<br /><br />I am using Johnson lower unit oil specifically for electric shifts.<br /><br />This winter (I live in the Boston area where it can get well below freezing)I drained the lower unit in case there might be any water in it it could not freeze. I then filled it with proper fluid to find no resistance. The wires started to get very hot due to the direct short.<br /><br />Any suggestions to the cause?

 

[OBJ]

Re: 1971 100HP Johnson Electric Shift Problem

Lily-pad....the solenoids won't show much resistance....6 ohms at best with the solenoids laying on the bench. I'd like to know more about the "hot wire" you experienced and which lower unit was it, the one that's on now or the old one you changed out. If our getting the right voltage to the shift wires when shifting, I'd look for a short somewhere in the lower unit or cable. Thanks.

 

[cbkellogg]

Re: 1971 100HP Johnson Electric Shift Problem

I noticed the hot wire on the lower unit currently mounted on the motor.<br /><br />I have a good VOM and tested both leads to a good ground on the motor. Both showed 0 resistance. I also tested the leads one to the other and found 0 resistance. I presume that for this to be the case, either both coils are fried and shorting directly to the case and thus lead to lead or the leads to both coils would have to be shorted to the lower unit case.<br /><br />Then I tested the spare lower unit (it had originally been the lower unit on my motor until I swapped it last year). I found the exact same conditions. Now, since the lower unit is off the motor, I can see that the leads are not damaged. This unit also shows 0 resistance from lead to case and from lead to lead.<br /><br />Thank you for your reply. I am baffled.

 

[OBJ]

Re: 1971 100HP Johnson Electric Shift Problem

Hi lily_pad...trying to keep up with your post.<br /><br />Do you have a service manual with wiring diagarams? The only wires going to the lower unit should be a green and blue wire. What is this "hot" wire your mentioning in your last post?

 

[cbkellogg]

Re: 1971 100HP Johnson Electric Shift Problem

Which ever lead (blue or green)is energized from the powerhead with the 12V becomes hot. So in neutral the one lead (I can't remember which color)gets hot. If in reverse, both leads get hot.<br /><br />Chris

 

[Buzzy McGraw]

Re: 1971 100HP Johnson Electric Shift Problem

you should have 8 ohms to ground from each-16 ohms between the two. If not-brocken wire(s)

 

[Joe Reeves]

Re: 1971 100HP Johnson Electric Shift Problem

Lily.... Should you find that you need the complete solenoid assy kit, I do have one new one left in my remaining stock. I can send you a picture of the assy etc via e-mail. Just remind me what we are speaking of. ReevesJ32@aol.com