Kubota HST safety switch problem

[Peter 315]

Or a defective switch. Jon

Have to start somewhere.......

 

[radair]

Same problem I had. I replaced the pedal safety switch ($44) and all is well again. That was frustrating blowing those 5 amp fuses over and over again.

 

[civilian]

Well, I went out this morning to tackle my HST problems. First I made a jumper to remove the HDT switch. I will order new one tomorrow from dealer. Then I replaced the 5 amp fuse with a 5 amp circuit breaker. Starts right up. Ran it for a few hours today with no problems. Thanks for all the help here on TBN. Jon

 

[Fallon]

If you have to replace a fuse once, that's odd but not a problem I usually try to debug. If it blows a 2nd time, that's a problem & you can't chalk it up to a bad fuse. You really need to figure out the root cause.

A fuse is just a small wire that melts in a specific (safe) location. If you replace the fuse with a bigger one it may be a wire that melts down & burns your whatever (tractor, house) down.

In an OEM electrical system, a blown fuse generally means something is shorting to the frame in some direct or indirect manner. In a custom or modified electrical system it could be an overloaded circuit. But not in any modern reasonably well engineered vehicle.

Putting in a breaker or continually replacing fuses is asking for problems to show up somewhere other than the safety of the fuse box.

The only way a bad switch should blow a fuse is if it permits things to short to ground, which would be a little odd. High resistance due to a corroded or internally fried switch would generally cause high resistance. That would cause wierd not working issues but not increased amperage to blow a fuse. I'd suspect chafed wiring or something in that circuit creating a path to ground.

 

[civilian]

When I get the new HST switch, then I will go back to the fuse after looking for chafing. The dealer suggested the fuse may be blowing because of the bad switch. Jon

 

[radair]

If you have to replace a fuse once, that's odd but not a problem I usually try to debug. If it blows a 2nd time, that's a problem & you can't chalk it up to a bad fuse. You really need to figure out the root cause.

A fuse is just a small wire that melts in a specific (safe) location. If you replace the fuse with a bigger one it may be a wire that melts down & burns your whatever (tractor, house) down.

In an OEM electrical system, a blown fuse generally means something is shorting to the frame in some direct or indirect manner. In a custom or modified electrical system it could be an overloaded circuit. But not in any modern reasonably well engineered vehicle.

Putting in a breaker or continually replacing fuses is asking for problems to show up somewhere other than the safety of the fuse box.

The only way a bad switch should blow a fuse is if it permits things to short to ground, which would be a little odd. High resistance due to a corroded or internally fried switch would generally cause high resistance. That would cause wierd not working issues but not increased amperage to blow a fuse. I'd suspect chafed wiring or something in that circuit creating a path to ground.

I did diagnose it to the safety switch, but I was able to get it to work by cycling the plunger a few times, which felt kind of crunchy. While I was waiting for the switch to come in I went though another episode with the blown OPC fuse. Manually cycling did not work so great this time.

 

[civilian]

Went to the dealer and picked up a new HST pedal switch. Surprisingly it has continuity when the plunger is in. Old one had no contiuity in either position or from wire to outside threads. Installed new switch and tractor starts like it should. But my switch cost $49, not radair's $44. Grrr. Jon

 

[jless1]

I put the same new safety switch in about one year ago and had no further problems. Now I am back to the same old thing. Is there a way to clean it. Can't afford to drop $50.00 every year. I still have the old one too.

John

 

[kenmac]

I put the same new safety switch in about one year ago and had no further problems. Now I am back to the same old thing. Is there a way to clean it. Can't afford to drop $50.00 every year. I still have the old one too.

John

just do as I did. remove it. No more problems !!