alternator purple wire only 10v

[pmtom1]

Smoked old alternator and put on a used one that we had out of a working motor. The output is only a little above 12 volts so after checking all connections and tightening them up did some searching here.

Red purple coming into the alternator is 12.5 all the time. But the purple wire going out is zero with key off is it supposed to be but only goes to 10 with key on. With or without engine running.

Could this be related to my low output?

I'm about to pull apart throttle assembly to check resistance through but....

Thanks

 

[wellcraft-classic210]

Are you checking those voltages at the alternator -- If so you may want to re verify all connections and have the alternator tested somewhere.

 

[pmtom1]

The output voltage was being checked directly off the alternator. The 12.5 output.

To check the red and purple wires, I cut them as I going to redo the connections. So the 10v ignition wire was off the alternator when tested. I did confirm continuity to the carb and shifter limit switch. Strange....

 

[Bt Doctur]

at 12.5 there is no alt output dont know what your trying to find out but the throttle assembly/control box has nothing to do with it

 

[Bt Doctur]

click to enlarge

 

[pmtom1]

Thanks BtD... Good point. But we had 14.5 at the battery while running...... How is that possible?

 

[Bt Doctur]

The output voltage was being checked directly off the alternator. The 12.5 output.

you cant have 14.3 with it runring and have 12v at the alt output at the same time

 

[wellcraft-classic210]

You may want to ensure your DVM has a good gnd contact point and recheck those readings // You may be OK if your getting 14.6 at the batt -- its likely at the alt output also.

 

[pmtom1]

Yea...I think it had to be contact issue with the output. I was using alligator clips to reach around stuff. Output now seems to be good.

Still wondering about the 10v at the purple with the key on. That was definitely a good contact. I DID have the wires (purple and red / purple) disconnected from alternator at the time.

Also, looking at the diagram BtD posted, my shift interrupt switch definitely has the purple on one side. I got continuity to the purple that attaches to the alternator.

 

[Bt Doctur]

if you would tell us WHAT your working on the correct pic can be posted not just a generic one. point ign use a ground for the SI, electronic ones use 12v at the switch