300U battery kill switch

Dave H (MI) · May 11, 2017

Jim gave me a great link to a replacement switch in my last thread. It made me look around a little and there are some slightly more expensive units that might actually fit in the hole in the dash so I would not have to find a place to install it elsewhere. My question is what should I look for in terms of electrical ratings? The knife switch I have now is the type they put in cars as a kill switch to prevent the slow discharge over time. It gets very hot while the tractor is in operation. The switches I am looking at say they are rated for 175-185 amps continuous and 1000 amps intermittent. Jim had mentioned the starter drawing around 300 amps but I am thinking this is intermittent. What does the tractor draw continuously? Anyone know?

D beatty · May 11, 2017

This is what I have for a battery disconnect on my Farmall 450. It works great at shows because key comes out and nobody can start it ( kid safe).

Bob M · May 11, 2017

Max continuous current through the disconnect will be the output rating of the generator/alternator - about 25 amps for your 300U.

Momentary switch rating should exceed the CCA rating of your battery.

AlinMO · May 11, 2017

I can't see why your switch would get hot running as there should not be that much current going through it - Unless you have a short are some part is not functioning correctly. Maybe you should drop/isolate 1 item at a time to see which one is drawing the current.

Dave H (MI) · May 11, 2017

That switch is the one Jim sent me the link for. I cannot see how it mounts? I'm not thinking you use the posts to mount it so how does that work? (he says hoping it isn't obvious!)

Janicholson · May 11, 2017

The rivets are tubular and take machine screws. Jim

D beatty · May 11, 2017

I made a bracket with a large hole for switch to stick through with two holes to bolt it to bracket with stove bolts( just above light). I ran a battery cable from negative post of battery to one side of switch and a cable from other side of switch to ground under bolt that holds top cover of trans-rearend cover.

gab · May 11, 2017

I put one of these on my Super M, says 125 amps continuous_500 surge for 6/12 or 24 volt. Never noticed it warm and don't see any reason why it would running, would think it would be 25 or 30 amps from the alternator.

300U battery kill switch

Dave H (MI)

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D beatty

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Bob M

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AlinMO

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Dave H (MI)

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Janicholson

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D beatty

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gab

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