Why the big spark when bypassing Solenoid?

[dogdad11]

I just got the '05 CarryAll II going by test-jumpering around the solenoid, but it makes a big spark when doing-so (New solenoid on order, btw!). If I remove the jumper for more than a few seconds and then reconnect I get the same spark, but don't if it's any shorter of a time. What's it doing? Acts like a giant capacitor but none to be seen.

... and what's with the resistor across the solenoid terminals? Seems like it's a continuous current-draw. Maybe to keep a cap charged?? But where and why?

[Sergio]

The Capacitors are inside the controller. The resistor across the big posts of the solenoid keeps the capacitors charged so when the solenoid closes, that big spark you are experiencing does not happen at the solenoid contacts possibly damaging them.

Once charged, a properly operating controller should require very little current to maintain the capacitors charged.

Remove and measure the resistor, should be around 450 ohms for a 48v system, the value is not critical as long as the resistor is not open.

If the resistor is fine, you need to find out what is on the controller side of the solenoid drawing current.

[dogdad11]

Interesting. I'll start digging around there, if I have time today. I noticed the resistor got hot yesterday, but didn't think too much about it at the time. About 100 milliamps then?

Seemed like it didn't cool down with the key off, but I'd imagine it should.

[Sergio]

I am afraid You have a bad controller.... Yes the resistor would charge the capacitors with about 100mA until near pack voltage, but after that the current should have been under 1mA.

Is the cart running? if so, I would make sure that when the pedal is not depressed and definitely when the key switch is off, that the controller logic is not being powered (as in someone by-passed a safety somewhere).

[dogdad11]

Thanks, Sergio, for your suggestions. Did not get to work on the cart today, but I'll look at it as soon as I can get to it. One of the other workers drove over something sharp and blew a tire on a mower - naturally at the farthest point in the park - and then tried to drive it back. Now we get to buy a new rim too.

I may be wrong about the resistor heating-up by itself, as I had the key on-and-off so many times while troubleshooting.

I appreciate your help.