1975 Johnson 70HP stator question.

Hi,

I have a 1975 Johnson 70hp 3 cylinder outboard. I have had issues with the engine charging the battery last summer. I took off the hood and measured the OHMS (resistance) across the yellow and the yellow grey stator wires. The manual says it should be 1.0 +/- 0.2 OHMS resistance. My measurements are 1.5-2.0 in resistance and i am wondering if that means that my stator has gone bad.

I have also checked my rectifier (which i changed last summer because it was bad) and it is still good. So no problems there.

Is there anything that i am missing or should I be checking the load across the positive battery terminal to check to see if the amp draw is greater than 6 amps. (6 amps is what the stator is rated at)

Is there anything else in the boat that could be draining the battery quickly while the boat is NOT running but the battery is hooked up.

I was thinking that the power trim/ tilt could be drawing power if it was shorting out or something to that effect. Also, does anyone have a wiring diagram for the power tilt/trim for my year and make of engine. i do have the original service manual for my motor but does not give any wiring information for the power tilt/trim assembly.

Thanks for all the help this forum has given me since 2005. It is absolutely awesome. Thanks again

Pat

Re: 1975 Johnson 70HP stator question.

According to your test the stator failed. But it sounds kind of if-fy to me.

Certainly, if the load exceeds the charge, the battery will discharge. I suggest disconnecting everything from the battery except the moror and run it awhile and then check the battery voltage.

You can also temporarilly install a suitable low-reading amp meter in series with the rectifier to see if the alternator is putting out.

You can also use that amp meter to check for draw from the battery when the motor is not running.

I assume the battery is good (??)

Re: 1975 Johnson 70HP stator question.

A simple test for a draw on the battery when NOT running is to remove one battery cable, rig a test light (or a turn signal bulb) between that cable and the battery.

If the light lights and stays lit then something is drawing power from the battery.

Some radios have TWO + wires, one switched on and the other a constant ON for the station memory settings. These radios often cause a test light to flash momentarily as the circuit charges up, then the light goes out. When this radio circuit goes bad then the test light stays on, the radio causes the battery to drain down.

Re: 1975 Johnson 70HP stator question.

That is a great idea. I will do once I can access the battery connections. My boat has a rear seat that is "frozen " in place by ice as it is winter here, but i will test it once it melts. Thanks for the information everyone...

Patrick

Re: 1975 Johnson 70HP stator question.

Okay,

i have been able to access the battery. I removed the battery and will take it into canadian tire to have to checked and recharged. I will then do the amp-draw test and then give you the results of my testing.

I can not run it to check the alternator output, but when it warms up then i will do it. Basically I want to check to see if the battery is being drawn on while the boat is not running anyways, because when i was using the boat last summer i would turn it off and then try and restart it and it wouldn't go, so i will see if this fixes the problem. Also i am going to get a second battery to run the stereo and lights etc. hopefully this will take all problems out of the senario.

Thanks all, and i'll let you know how it goes...

Pat

Re: 1975 Johnson 70HP stator question.

So I had the battery checked at Canadian Tire, and it is shot. So i had them charge the battery up just so I can test the amp draw...and guess what...the accessories line was drawing 4.0 amps...and I don't know how? It was like 3.58 when I had the red multimeter lead plugged into the red connection on the meter, and the black multimeter lead plugged into the fused 10A connection on the meter.

So now i would like to know what the heck is drawing so many amps from the accessories line. All I figured I had on this line was the stereo...is it possible for a car stereo to draw that many amps?...Also i noticed when I touched the accessories line to the battery terminal it would spark lots, a very bright color fo yellow spark...so how do i track down the issue i am having with this thing.

Thanks for the help so far everyone...thanks.

Patrick