Starting one motor kills the other
Tried the search, no love, so forgive me if this is a rehash.
This week I experienced a new problem. After "trolling" an hour or two on a single motor (Yam 150s), I went to start the other to run to a new location. This attempt to start killed the other motor. Both batteries were charged at the time. For a short while, neither motor would turn over, rather I would get a quiet ratcheting-type sound. Then I got one to start, and the second again killed the first.
I started by cleaning all the contacts on the power posts. That seemed to clear it, but it recurred once later, less severely. Eventually, both motors started and ran normally.
I'm thinking it's a ground issue, as the clicking is reminiscent of problems starting a car when the problem is poor electrical connections. My guess is it's somewhere in the power posts, since it has affected both motors at times. All other electrical accessories functioned normally this entire time.
I don't think it is weak batteries, clogged filters, or bad gas.
Any other thoughts?
I agree with the ground issue as I had a similar problem recently I changed all ground wires and cleaned the grounding location and has worked fine since. If that does not solve the problem you may look at your battery selector. I was told that that can cause problems as well. Good luck
Most anytime that you have a electrical issue look at the ground first , this is true like 90 % of the time. Most of the time with trailer wiring it will be a ground problem. Good Luck
How old are your battery?
Batteries are only a couple years old. One got hooked up incorrectly, seems to be less able to hold a charge, but got it tested as I was about to replace it, and it checked out OK. Other is very strong.
Fired up both motors individually last night, no problems. Didn't try to fire both up. Hope the cleaned contacts took care of the issue.