No start issue

[dmoore]

No. This is just firing the parts cannon. It's the most expensive and frustrating way to fix a problem, and usually takes the longest.

There is a lot more troubleshooting to be done. Getting those wiring diagrams is the first step.

Mark is being funny.....Service manual is on the way. I am not a parts changer. Its more than likely a safety switch, likely the clutch switch adjustment.

 

[Henro]

Mark is being funny.....Service manual is on the way. I am not a parts changer. Its more than likely a safety switch, likely the clutch switch adjustment.

The manual I linked to above has a supplement in the rear which covers the B7800.

If you want to get a head start download it, if you are waiting for a printed copy your paid for. An electrical diagram is included. Kubota states the following:

Use this workshop manual together with workshop manual for B2410, B2710 and
B2910.

B7800HSD tractor is simplified from B2910HSD. Front lights, seat, rear fender stay,
hydraulic control valve, electrical system and lower link stabilizers are mainly changed.

Engine, clutch, transmission, brake, rear axle, front axle and steering are mainly
same.

 

[dmoore]

So while I was waiting on the service manual to show up I decided to do a little more investigating on this issue. I pulled the dash assy to probe the key switch control wire and found 12v present. Looking around under there I spy this small black box with a 10 pin connector. I later found out through my dealer this is a controller. 12vdc was going in but not coming out. Apparently after it leaves the key switch it travels to that controller. I jumped it out and viola, starter engagement. $220.000 later it is ordered. Much more $$$ than I thought it would be. After 16 years this is the only problem I have ever experienced. I'll take it!

 

[dmoore]

So while I was waiting on the service manual to show up I decided to do a little more investigating on this issue. I pulled the dash assy to probe the key switch control wire and found 12v present. Looking around under there I spy this small black box with a 10 pin connector. I later found out through my dealer this is a controller. 12vdc was going in but not coming out. Apparently after it leaves the key switch it travels to that controller. I jumped it out and viola, starter engagement. $220.000 later it is ordered. Much more $$$ than I thought it would be. After 16 years this is the only problem I have ever experienced. I'll take it!

Well that didn't work.

 

[Mark_BX25D]

Spray and pray can get expensive.

 

[#40Fan]

Did you get your service manual yet? Have any idea what those extra wires go to?

If I had to guess, I'd say they go to the safety switches as well as fuel control solenoid(s).

 

[dmoore]

Did you get your service manual yet? Have any idea what those extra wires go to?

If I had to guess, I'd say they go to the safety switches as well as fuel control solenoid(s).

Still waiting on it. Out of all the wiring diagrams online I cannot find one for my tractor. I can jump the black and white wire coming from the key switch at the controller plug with the black and yellow gong to the starter right beside it and starter engages. So something is telling the controller through ground? to do this. There are 6 safety switches on this tractor and I have jumped them all out. There are two other little boxes behind dash but none of the wires match to to the key switch or controller wiring. I know one of them is for the headlights.

 

[dmoore]

Still waiting on it. Out of all the wiring diagrams online I cannot find one for my tractor. I can jump the black and white wire coming from the key switch at the controller plug with the black and yellow gong to the starter right beside it and starter engages. So something is telling the controller through ground? to do this. There are 6 safety switches on this tractor and I have jumped them all out. There are two other little boxes behind dash but none of the wires match to to the key switch or controller wiring. I know one of them is for the headlights.

So I haven't had much of a chance to get on here but the issue with my tractor was the hydrostatic safety switch. The securing nut had loosened cocking the switch just out of line with the rod so it wasn't actuating it. Hard to see up there. Thanks to all who posted. Dave