I have a feeder that goes on the back of my truck for feeding cattle the power supply wire to the feeder motor " starter motor" is #4 welding lead the power wire is broken at a solonoid that is mounted under hood that is closed or activated by a switch in the cab. I installed a fuseable link in the power lead to the switch in the cab what do I need to do to find out or how can I tell what the smallest amperage fuse that will close the solonoid and keep it closed without being too much. I realize there is always trial and error but If someone can tell me a quicker way I would greatly appreciate it. TIA



BTW I know its a shame to turn the RED ROCKET into a feed wagon but I have no choice it sucks to be a grown up sometimes.

 

Did you make this feeder yourself? or did you buy one with the motor and all on it already? If you bought it, the manual for the starter will tell you what the amp draw is...just get a fuse with matching amp draw...the only other way I know to check for amp draw is with a meter.

You could try the "trial and error" method if there is no manual to look at, just remember to start low with the fuses...ie, if you think the amp draw maybe 20 amps, start with a 5 and work your way up from there...always better to blow a fuse that burn up wires

 

If you can get to the motor on the feeder it might give you its max current rating, in AMPS. Right if so then you could use that number with a little margin and try that one. Heck worst case vist a shop and ask the tech to put a current probe on the line and measure max current when you turn it on. . .

 

Thanks guys I did not build this feeder I jerked it off of another truck we had Sooo I dont have any kind of manual the motor is just a basic starter for a chevy 350 the local parts store keeps them in stock with the shafts cut short just for us I guess I could call the parts store and find out the amp draw. Thanks for the help so far I've got a 20 in it now and its just barely enough I can see that its starting to melt not sure of the draw of the motor while under load

 

The parts store will definately be able to tell you the draw/current. 20 sounds about right for that size starter...

 

Check the solonoid coil resistance with an ohmmeter (resistance meter).

Then use the following formula the get the current draw.

Voltage (12v) devided by resistance (Ohms) equals Current (Amps)

 

Gracias boys I'll let you know how it all works out thanks again for the help

 

I called the goob at the parts store he has no clue about the draw on the motor period he said it is 12 volts and has three mounting ears Wow thanks for the enlightenment!!!!! 98xc800 will this formula tell me how big the draw is on the switch wire or on the actual solonoid does the draw on the switch wire change or does it always take the same amount of amps to close the solonoid no matter what the motor draw is .

 

The formula will give you the current draw of the pickup coil of the solonoid . The current draw of the solonoid coil is constant, unrelated to the current on the solonoid main contacts.

 

Exactly what I found out from the guy who installs these feeders for a living. the draw on the switch wire is constant and just in case any one wants to know a 15 amp fuse is more that enough. Thanks for all your help guys.