Need help please with Kubota BX1800 electrical issues.

[RussB]

Hello,

First time post. Sorry for the length but trying to be thorough. I have a first gen BX1800 (prior to the seat safety switch in later models). It's been a workhorse for over 20 years but now it has me stumped and any insight would be greatly appreciated.

1. Normal operation... If I turn the key to the ON position fuel pump clicks, battery light comes on and other electrical items like headlights etc operate.

2. Now... I turn the key to the ON position and nothing happens. No clicking in the fuel pump, no other electrical items work.

3. If I disconnect the battery and re-connect it when I turn the key to the ON position the fuel pump clicks and other electrical items work BUT JUST ONCE. If I turn the key to OFF and repeat nothing happens until I disconnect the battery again.

4. After re-connecting the battery and it has the working condition from number 3 above and I attempt to pre-heat the glow plugs sometimes the pre-heat light will come on for a second or two then it goes out. If I try to start it I don't get any crank on the starter. Then as mentioned above in number 3 another try results in nothing.

I know throwing parts usually isn't the correct thing to do but I've done it.

A. New starter
B. New Timer relay
C. New IC regulator (looks like all circuits go through there)
D. Checked all the fuses
E. New Battery

I do have the wiring diagram. Any help or insight would be greatly appreciated.

 

[85Hokie]

Russ = Welcome to the forum!

Did this come on all of a sudden?

three items to look at :

1) check all the cables to the battery and to the starter - both are new, but is the wire ok? Must look deep into the wire, cut back some insulation if need be to look closer.

2) could a mouse or rat have chewed through anything?

3) Your key switch may have a bad spot on a contact.

Have you tried to jump it by crossing the solenoid AT THE starter? Small screw to larger bolts? (In neutral and out of gear)

Tell more about how this started...... did it sit for a while? Did it start fine yesterday? etc......

Report back - many here will jump in and help

 

[RussB]

Russ = Welcome to the forum!

Did this come on all of a sudden?

three items to look at :

1) check all the cables to the battery and to the starter - both are new, but is the wire ok? Must look deep into the wire, cut back some insulation if need be to look closer.

2) could a mouse or rat have chewed through anything?

3) Your key switch may have a bad spot on a contact.

Have you tried to jump it by crossing the solenoid AT THE starter? Small screw to larger bolts? (In neutral and out of gear)

Tell more about how this started...... did it sit for a while? Did it start fine yesterday? etc......

Report back - many here will jump in and help

Thank you for responding.

Started fine last week. Shut it off and the issue above started to happen the next time I tried to start it.

No evidence of rodents etc

I checked battery cables for continuity only. I will check the battery cables as you suggest.

I haven't checked the key switch yet but in looking at the wiring diagram the contacts that engage after the ON position do connect back to the first position. Weird thing is if I disconnect the battery and re-connect It get power again when the key is in ON position but only once.

I haven't tried to jump the starter

Sorry for the rookie question... How is the key switch removed? There's a chrome ring with a slot on the outside of the dash panel. Does that just screw off? I haven't taken it off yet because I didn't want to break it.

 

[BX'r]

test these

Engine stop solenoid and
timer relay

 

[GreensvilleJay]

replace the battery cables !
any that are older than +-5 years could be bad....
in your 1st post you replaced battery and starter,no mention of cables though.

 

[RussB]

test these

Engine stop solenoid and
timer relay

Thanks. I'll test them.

 

[RussB]

replace the battery cables !
any that are older than +-5 years could be bad....
in your 1st post you replaced battery and starter,no mention of cables though.

Thanks, I'll do that and report back.