ZD28 Will not start

KCSparky

New member

Equipment
ZD28
Aug 24, 2015
1
0
0
DeSoto, KS
Hi everyone! I recently purchased my first Kubota mower (used) and I love it...until this weekend when it would not start. It ran fine when I put it up when I used it last but now, nothing.
Here is a quick rundown.....
Key on - panel lights up and glow plug function is normal and I hear the fuel pump running.
Key to start - nothing.
I jumped around each of the 5 safety switches (seat, PTO, brake and 2 motion controls) one at a time trying to isolate a bad micro switch with no success.
Next, because its a diesel, I jumped around the starter relay and it fired up instantly. This was great but it would not shut down with the key switch so I made a temp. jumper with switch to the engine cut-off solenoid directly to the battery. After resolving that I found that the machine ran and would cut fine except now none of the safety switches function. I can have the brake off, pto on and the motion controls in the operation position and be off the seat and it will still run. I've also noticed the temp gauge is not reading either but the fuel gauge and hr. meter are working.
I'm not sure what the "Combination Box" function is but it seams logical that this is the source of the problem but before I run out and drop a bunch of $$ on a replacement I wanted to see if any of you had run into this issue before and could shed some light on my predicament.
Thanks for your help!!!
 

rentthis

Member
Lifetime Member
May 30, 2012
998
21
18
summerville,sc
I had a ZD-18 that did the same thing. The difference being, if I turned the switch to start often enough, 5-10 times, it would start. It turned out to be the starter. It would always start from a jump. I bought a cheap starter online and that corrected the problem. Strange but true.
 

D2Cat

Well-known member
Lifetime Member

Equipment
L305DT, B7100HST, TG1860, TG1860D, L4240
Mar 27, 2014
12,979
4,363
113
40 miles south of Kansas City
KCSparky, whatever it is, you can ride your bicycle over to Coleman's for parts! They have it all, with good service.

Welcome aboard.
 

ntech5

New member

Equipment
zd28
Aug 29, 2015
1
0
0
fredericksburg
Hi everyone! I recently purchased my first Kubota mower (used) and I love it...until this weekend when it would not start. It ran fine when I put it up when I used it last but now, nothing.
Here is a quick rundown.....
Key on - panel lights up and glow plug function is normal and I hear the fuel pump running.
Key to start - nothing.
I jumped around each of the 5 safety switches (seat, PTO, brake and 2 motion controls) one at a time trying to isolate a bad micro switch with no success.
Next, because its a diesel, I jumped around the starter relay and it fired up instantly. This was great but it would not shut down with the key switch so I made a temp. jumper with switch to the engine cut-off solenoid directly to the battery. After resolving that I found that the machine ran and would cut fine except now none of the safety switches function. I can have the brake off, pto on and the motion controls in the operation position and be off the seat and it will still run. I've also noticed the temp gauge is not reading either but the fuel gauge and hr. meter are working.
I'm not sure what the "Combination Box" function is but it seams logical that this is the source of the problem but before I run out and drop a bunch of $$ on a replacement I wanted to see if any of you had run into this issue before and could shed some light on my predicament.
Thanks for your help!!!
I am in literally the exact same situation as you. I am still in the process of figuring it out. Control box was replaced harness was swapped regulator was swapped. No power to starter solenoid coming out of control box b/y wire into from ignition switch is hot with key on nothing out. Relay inside the box is not closing to complete the circuit i can jump solenoid and it will run i personally am going to break down and purchase the WSM for the proper diagrams as some of them online don't seem to match up correctly and there is no info on the regulator and what each of the wires do at least maybe with the grainy photos i'm finding and my poor eyesight.

I will keep you updated if i come up with a fix or not.
 

Cathlab

New member

Equipment
Ford 1710
Sep 29, 2018
1
0
0
Mounds, Oklahoma USA
I am in literally the exact same situation as you. I am still in the process of figuring it out. Control box was replaced harness was swapped regulator was swapped. No power to starter solenoid coming out of control box b/y wire into from ignition switch is hot with key on nothing out. Relay inside the box is not closing to complete the circuit i can jump solenoid and it will run i personally am going to break down and purchase the WSM for the proper diagrams as some of them online don't seem to match up correctly and there is no info on the regulator and what each of the wires do at least maybe with the grainy photos i'm finding and my poor eyesight.

I will keep you updated if i come up with a fix or not.
I am new to the forum and started with your same problem. It was recommended from another site to us a relay kit sold on ebay and at John Deere. JD kit part #AM107421 Very easy to install and fixed my nagging problem for two years. Cost 35 bucks. An unbelievable fix.
 

dsc440

New member
Dec 11, 2017
24
0
1
US
Unplug the ignition switch & check for 12v @ switch side of harness when you turn key to start position - you will need to jump 12v from battery to the in feed terminal so the switch has power - then see if you have power coming back out when you turn it , mine only had 9-10v after plugging switch back into the harness but full 12v when disconnected- even though all the safety switches checked good , the combination box was bad - I ran a new wire to the solenoid and powered a push button start switch straight from the battery with an inline fuse - I can turn key on , warm glow plugs - then hit new button & release/ I bought 1 combo box a few yrs ago but wasn't dropping another $250+ !!! On mine the seat switch tests good but doesn't work in the combo box, all the others will shut it down, I can live with that - good luck

Sent from my SM-N920V using Tapatalk
 

dsc440

New member
Dec 11, 2017
24
0
1
US
Was having similar problems and couldn't find any info - figured I would put it out there just to try and help in case anyone was looking around - I saw the date

Sent from my SM-N920V using Tapatalk