transmission light is ON Bobcat 843

[donald73d]

I replaced both bulbs (engine oil pressure and transmission) in the gauge cluster. Both were broken. The engine oil press. light comes on when key is turned to on but goes off once engine is running as expected. The transmission light stays on when the engine is running, at least for the three minute test I did today. I added 2 QT of fluid to bring it to exactly full and it still happens. Its warm here in upstate NY (40F) for winter. I guess change the hydraulic filter as the next step?

 

[OldMachinist]

First check wire to the sender isn't grounded somewhere.
Next put a gage into the port where the sender is to check the actual pressure. I think the light is supposed to go off between 17-20 psi.

 

[donald73d]

First check wire to the sender isn't grounded somewhere.
Next put a gage into the port where the sender is to check the actual pressure. I think the light is supposed to go off between 17-20 psi.

Well since the previous owner probably never change the hydraulic filter, this was a good push to do it. I changed the one thats straight down under my right arm. No luck yet. Does the hydraulic fluid oil need to come up to temp before the light goes off?

 

[Tazza]

Well since the previous owner probably never change the hydraulic filter, this was a good push to do it. I changed the one thats straight down under my right arm. No luck yet. Does the hydraulic fluid oil need to come up to temp before the light goes off?

No, it should turn off as soon as you start the engine.
It could be a bad sender too. My 743 uses a common light for hyd temperature, low charge pressure and plugged hydraulic filter. If yours is wored the same, any of those three senders could be bad.

 

[donald73d]

No, it should turn off as soon as you start the engine.
It could be a bad sender too. My 743 uses a common light for hyd temperature, low charge pressure and plugged hydraulic filter. If yours is wored the same, any of those three senders could be bad.

Also with skidder cold, when I turn the key to ON (but do not start it) only the engine oil pressure light comes on. Not the transmission light. And the hour meter does not work, but does when I pull it out and connect it to 12V directly. I think the dual function pressure switch is not working, or at least the part that gives power to the hour meter. Tazza - you are correct there is one temp and two pressure sender, and any could be defective.

 

[Tazza]

Also with skidder cold, when I turn the key to ON (but do not start it) only the engine oil pressure light comes on. Not the transmission light. And the hour meter does not work, but does when I pull it out and connect it to 12V directly. I think the dual function pressure switch is not working, or at least the part that gives power to the hour meter. Tazza - you are correct there is one temp and two pressure sender, and any could be defective.

I think you are on to something. If the pressure switch does not work right, you get no power to the hour meter. A new sender shouldn't be too expensive at the dealer either.

 

[donald73d]

I think you are on to something. If the pressure switch does not work right, you get no power to the hour meter. A new sender shouldn't be too expensive at the dealer either.

I did things one at a time. I just replaced the hydrostatic filter (in engine bay) and the light does not come on when running. It did before. The old filter in there was a WIX which is not as long as the Bobcat filter. I still think there is a problem in that the trans light should come on before the engine is started. The WIX seems to be a replacement for an old Bobcat number. They changed numbers and maybe the replacement number is longer.