Low power after while

[radioman]

But they don't drive them through the sand.

[TheOldMan]

Since occasionally I have to move the f/r switch to forward twice to move, I decided to remove the switch and see what I could see. Labeled all the wires and removed one at a time. Used a small stainless steel toothbrush to clean up all the terminals as I went. The switch is the older type, looks like phenolic rather than plastic. Found very minimal corrosion on a couple of the terminal studs. Opened up the switch, and found massive copper studs, all of them very flat and highly burnished on the connecting face. The face of the ring that holds the studs in place for the connecting wires had a stiff film on and around it that I believe is Penetrox residue. Removed the spring mounted studs from the cam, burnished the buss bars and under side o the stud heads, although they were very clean and shiny when removed, added a slight coat of Penetrox under the heads and re-assembled. Placed a very small amount of penetrox on the plastic ring surrounding the connection studs, for the stud faces to ride on between connections, both for it's anti-oxidation and lubrication. Adjusted the tension on the switch shaft so that the spring inner spacer just stood proud of the cam surface.

[radioman]

Originally Posted by TheOldMan

Since occasionally I have to move the f/r switch to forward twice to move, I decided to remove the switch and see what I could see. Labeled all the wires and removed one at a time. Used a small stainless steel toothbrush to clean up all the terminals as I went. The switch is the older type, looks like phenolic rather than plastic. Found very minimal corrosion on a couple of the terminal studs. Opened up the switch, and found massive copper studs, all of them very flat and highly burnished on the connecting face. The face of the ring that holds the studs in place for the connecting wires had a stiff film on and around it that I believe is Penetrox residue. Removed the spring mounted studs from the cam, burnished the buss bars and under side o the stud heads, although they were very clean and shiny when removed, added a slight coat of Penetrox under the heads and re-assembled. Placed a very small amount of penetrox on the plastic ring surrounding the connection studs, for the stud faces to ride on between connections, both for it's anti-oxidation and lubrication. Adjusted the tension on the switch shaft so that the spring inner spacer just stood proud of the cam surface.

Does it run better now?

[TheOldMan]

It does seem to respond better. I charged it all night, then took it to the garden to an area that I had tilled pretty deep a couple of days ago, and took it for a trial. Pushed through the soft stuff pretty good, but the voltmeter dropped to about 35 volts, back on hard ground, 38+. Decided to take it on it's maiden asphalt run down to the corner and back, 1/2 mile each way. Couple of small hills. Thought I was gonna have to get off and push. Other than that, OK. VM dropped to 34-35 volts on the hills, Is this normal?

[radioman]

In other words all that work you did not solve your complaint. You may have a weak battery(s) or a weak charger. You are going to have to do some more voltage tests. Put it back on charge and check the battery bank voltage periodically while charging. Voltage should get up over 44 volts near end of charge. Next check for the voltage JB mentioned the next morning. If all that is ok you are going to need to check the voltage of each individual battery. It would be good idea the check them with your sprayer running and any 12 accessory running to check them under load. Just because the batteries are new don't mean one is not bad.

[TheOldMan]

I decided to run it in the sand and see if anything got hot. Started to smell something like hot plastic, so yanked the seat, and felt everything I could reach. Controller was slightly warm and F/R switch a little warmer. nothing else. re-installed the seat and started to back out, dropped the left rear wheel in a hole - shifted to forward, started to spin just a couple of revolutions - now dead. Solenoid clicks, that's all. Back to square one. Found what looks like a small wafer type capacitor tied across B- & B+ on the controller with a lead broken off. No markings on it. What is it and whats it for?

[TheOldMan]

Found that problem! Broken lead on A2 at the motor.

[radioman]

Originally Posted by TheOldMan

Found that problem! Broken lead on A2 at the motor.

Probably what has been part of the problem the whole time. Started out as poor connection and the harder you ran it the worse it got. Actually all the work you did on it helped deliver more power and finished the job. You should be able to get that repaired. The little round thing you mention is probably a spike suppressor or overvoltage device. I would try to find out what it is and replace it.