1987 Johnson 140 Rectifier/Regulator Problem

[bayprowler]

I just installed a new rectifier/regulator on my 1987 Johnson 140 since I was not getting any charge to the battery and the tachometer stopped working. After the install, I have charge to the battery but the tach still does not work. I have checked over the wiring thoroughly and may have found a possible problem. There is an "extra" wire that the manual and the new regulator instructions don't mention..it is the hot lead from the ignition switch (purple in color). All other wires on the rectifier/regulator are matched up to the appropriate engine side wires (red lead for power goes to starter solenoid, the 2 yellow wires are paired up to the wires coming from the stator, the 2 purple wires are matched and the 2 gray wires are matched - the tach sending wire). The "extra" wire I have led to the purple wire terminal since the regulator instructions say to make sure a full 12V is happening at the purple wires, which it does (13.03V). The gray wires have 0V which explains why I'm not getting any tach info, and the the two yellow wires have 12.25V and 12.33V. The battery is getting a slow and steady charge. I previously led the "extra" wire (ignition hot lead) to the yellow wires, gray wires, and the now the purple wires, just to test if anything will work. Maybe that damaged something? Also, when I first tried out leading the "extra" wire to the purple wires, the tach needle jumped up to around 800 when the engine first cranked and then returned to 0 just as quick. Now it does not do that at all. Any thoughts?

 

[etracer68]

Re: 1987 Johnson 140 Rectifier/Regulator Problem

Welcome, The new reg/rec have a extra wire, tape it off and dont use it. At least that is what I have read before. I think it is for newer motors. I changed my reg/rec last year on my 1987 90HP Jonhson with a 35 amp, and it too had the extra wire. Every thing works as it should.

 

[steve7676]

Re: 1987 Johnson 140 Rectifier/Regulator Problem

I have the same motor and the same problem. "TACH" I hooked black to ground, purple to "ON" hot, and gray to the gray signal wire. This motor is a 12 pole and from what I have researched you should divide that by two and that is what your pole settings on the tach should be set at if your using a old tach. So with it set on 6 I started the motor, the needle jumped up to 800-1000 then a little smoke. Now my Tach smells like burnt plastic. Also poped the 10am 32 volt fuse at the solenoid. Now now key power, replaced the fuse now its starts. The gray wire is suppose to be the signal wire. Does anyone know how to measure the strength of the power coming out of that thing? I thought it was suppose to be millie amps. I bumped into it and it lit the hair on the back of my neck. I put a test light on it and it started to melt the light.