hst control switch ohm test

jgtools

New member

Equipment
kubota L 3240 hst
Mar 29, 2013
14
0
0
Dassel,Mn 55352
i removed the hst control switch off my l 3240. to determine if switch is bad,and needs replaced, I did some searches, and If I understand the test procedure is to ohm it out , with control ohm tested on low, medium and high settings. ohm readings should be around 200 , 500, 800 if control switch is good. what Im not sure is, how to correctly ohm test the control switch, with switch unplugged it has 5 pin connection. any advice,before ordering a new control switch @ 120.00 smackers. thanks JG
 

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Stubbyie

New member
Jul 1, 2010
879
7
0
Midcontinent
I'm not familiar with your particular setup or having a machine with a pushbutton HST selector as mine are manual.

Can you find the wiring diagram online or in the Parts or Shop Manual? Good to have and this may be a reason to obtain same.

You indicate the switch has 5 pins. One would be power in, one probably is ground. You might be able to figure this out by back-tracing your wiring harness to a connection and / or by wire color. Then the three remaining would be the H, M, L settings you mention.

Sit down with the switch, check readings between pins and write down the ohm readings. I suspect you'll see a pattern; and if you don't you've confirmed a bad switch.

Depending on age of the unit, I'd think a bad switch would be a low probability. Possible, but borderline unlikely. Switches like this are designed with a life of 250,000+ cycles. Unless there is weather intrusion or physical damage or corrosion on a pin or the socket.

I'd also suggest you use an analog-type ohmmeter like Simpson (top line) or Harbor Freight / Radio Shack / Lowes instead of a digital. You're not looking for a highly specific number of ohms, but rather full scale, 3/4-scale, half scale, 1/4-scale, that kind of thing. A digital meter might drive you crazy flickering between digits and if an area of flourescent lighting might give you strange values.

Please post back your experiences and what you learn so we may all gain knowledge.
 

jgtools

New member

Equipment
kubota L 3240 hst
Mar 29, 2013
14
0
0
Dassel,Mn 55352
Thanks for the tips Stubbie,I'll let you know what I have. I did have a code 85, that code refers to control switch in trouble. I m looking at buying a work shop manual for my tractor, $135.00 from the dealer. Hoping to find the manual for a little less if possible. Thanks again,jim
 

Stubbyie

New member
Jul 1, 2010
879
7
0
Midcontinent
Something else to consider is that the dashboard trouble code may be indicating something is wrong in the entire switch 'system'. For instance, that switch connects to something---perhaps an actuator?---that could also be experiencing problems.

Checking resistance / continuitity in the switch only may not track the problem.

In a case like this the WSM would be invaluable in trouble-shooting. Yep, it's expensive, and not used every day, but well worth the investment especially if you intend to keep the machine, as we tend to, until the wheels fall off.

Please continue posting back with your continuing experiences so we may all learn.
 

Burt

New member

Equipment
L3700SU, box blade, 6 foot rhino blade, 1 bottom plow, 3 point receiver hitch.
Mar 24, 2012
337
1
0
Goldendale, WA USA
i removed the hst control switch off my l 3240. to determine if switch is bad,and needs replaced, I did some searches, and If I understand the test procedure is to ohm it out , with control ohm tested on low, medium and high settings. ohm readings should be around 200 , 500, 800 if control switch is good. what Im not sure is, how to correctly ohm test the control switch, with switch unplugged it has 5 pin connection. any advice,before ordering a new control switch @ 120.00 smackers. thanks JG
jgtools,

If you can afford a Fluke digital meter, they are bullet proof. The work well in all circumstances and are good for a lot more than OHMS.

BTW, I have the factory shop manual for the L3800 which includes the previous two models of Kubota tractors. Yes, there is a wiring diagram with colors, voltages and a great map to where the wires go. It's very accurate. The price of the manual is about what you are paying and IMO, worth it. Otherwise, you're not always going to be sure of what to trace.

Good luck on your quest.

Looking forward to your next post on what you find out.

Burt