With my Bobcat DK 45 HST, the gear shift lights won't come on and the engine won't start. I took out the potentiometer by removing seat and tested it. It seems to work OK going smoothly from about 20 ohms to 1850 ohms after cleaning the contacts. I reassembled it but the gear lights still don't come on. Any way to test the Pre Heat-Cruise module next to the potentiomenter? I would rather not order one and find out it is not the problem. Any other suggestions?
DK45 HST won't start
- Thread starter kengreen
- Start date
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ritcheyvs
Veteran Member
OK, I don't have a HST but I'd be inclined to check that the pot is sending thr correct voltage to the cruise unit. I don't have a DK HST manual but the EX HST manual says:
When the range shift sensor is moved to the
setting points (N(3.1 ± 0.3V), M(2.5 ± 0.3V),
N(1.9 ± 0.3V)), the N, M and N lamp flashes accordingly.
Maybe somebody with a real DK HST manual can verify these numbers.
So I'd check those voltages. Just because the pot runs smoothly does not guarantee that it provides the correct resistance/voltage to the cruise unit when in neutral. IMO, if the voltage to the cruise unit is correct and you get no neutral light and no crank, I'd suspect a bad cruise unit or a bad fuse feeding the cruise unit (there are 2) or a ground problem.
When the range shift sensor is moved to the
setting points (N(3.1 ± 0.3V), M(2.5 ± 0.3V),
N(1.9 ± 0.3V)), the N, M and N lamp flashes accordingly.
Maybe somebody with a real DK HST manual can verify these numbers.
So I'd check those voltages. Just because the pot runs smoothly does not guarantee that it provides the correct resistance/voltage to the cruise unit when in neutral. IMO, if the voltage to the cruise unit is correct and you get no neutral light and no crank, I'd suspect a bad cruise unit or a bad fuse feeding the cruise unit (there are 2) or a ground problem.
k0ua
Epic Contributor
There is 5 volts applied to one side of the pot. and ground to the other side.. the wiper of the pot should move smoothly thru its range with a variable voltage as you move from ground to 5 volts. If you don't have 5 volts on the high side of the pot and ground on the other, then check the fuses or replace the module.
ritcheyvs
Veteran Member
That's good. But what did it read in the two neutral positions? Neutral is the issue, not high or low.
k0ua
Epic Contributor
This seems right. If the cruise module is working correctly, the output pin 21 (it is on the second smaller of the two connectors. throws a ground thru a diode to the low side of the start relay coil. The wire color at the relay appears to be blue. I don't know where the diode is located but it is in series with the ground side (blue) of the start relay coil (start relay is first relay on firewall on the left as you view the tractor by standing in front of it.) If you ground this contact on the relay where the blue wire is with a jumper, and hit the starter it should rotate. Keep in mind the logic in the cruise module also checks the status of the PTO switch.. before it will throw this ground out to the start relay. I beelieve you mentioned no range lights on the display module, so this is looking like a cruise module failure.. But I would try the ground jumper to be sure before I bought that module. I am not sure how much they cost. By the way did you pull all of the molex connectors on the cruise module and inspect them? All clean and happy?
k0ua
Epic Contributor
At this point, you should really have the workshop manual so you can do your own tracing, and troubleshooting.
SSdoxie
Elite Member
Ken has been posting this on both Kioti and Bobcat forums. Below is the Bobcat schematic. I wanted him to check for proper inputs, but according his response on Bobcat forum the wire colors are not matching. It takes 12v power input from the 20a fuse (red/white wire) and secondary signal from the starter relay with key in start mode. schematic show that to be red/blue wire, but Ken mentions he has a sold red wire and a red/white wire.
Mu question is what should he see regarding voltage if any coming from the ground side of the Start relay through that diode.
Hope you guys can help out, I just want to make sure he is getting both inputs required.
View attachment CT440_CT445_CT450 6987079 enUS sm 01-14,electic schematic.pdf
Mu question is what should he see regarding voltage if any coming from the ground side of the Start relay through that diode.
Hope you guys can help out, I just want to make sure he is getting both inputs required.
View attachment CT440_CT445_CT450 6987079 enUS sm 01-14,electic schematic.pdf
k0ua
Epic Contributor
Dennis I would think he would have around 12 volt on the wire heading back to the cruise module thru the diode if the start section of the key switch was engaged. The voltage would go thru the start relay's coil and since the diode is forward biased, it should go right thru it with a .7 volt drop. But if the ground thrown by the cruise module is not there no appreciable current would flow in the coil and the coil would not be energized.
k0ua
Epic Contributor
Dennis there are a lot of differences in the Bobcat schematic and the Kioti schematic.. I did not know they were that far apart..
Thanks. I have only measured the voltage coming OUT of the potentiometer between the white and black wires. The voltage goes from 1.29V at Low, 1.76 at Neutral1, 2.48 at Medium, 3.16 at Neutral2 and 3.68 at High. I have not been measuring voltages on the preheat cruise module. I don't understand where to find or
ground the blue wire, pin 21. If the pre-heat cruise module schematic s different from the Kioti module, then I assume I need to find a Bobcat module which may be a problem.
ground the blue wire, pin 21. If the pre-heat cruise module schematic s different from the Kioti module, then I assume I need to find a Bobcat module which may be a problem.
SSdoxie
Elite Member
Bobcat had a better idea?????????????? :cool2:
SSdoxie
Elite Member
Before you start changing modules, Identify if you are getting both voltage inputs. You getting one of them, the 12v from the fuse, otherwise you wouldn't have any voltage feed to the Potentiometer. Try swapping the Start Relay with one of the other ones like it. Confirm that relay is functional and it has a good solid ground.
k0ua
Epic Contributor
ok couple of things, you called it a bobcat DK45hst.. I assume it is a bobcat right? NOT a DK45hst.. what would that be a CT445? As for the module being the same between the bobcat and the Kioti, I don't know for sure, The schematic that dennis sent along looks quite a bit different, The same but a lot different, including wire colors. What I would do. is find the start relay, It has a coil, 12 volts comes from the Start contacts on the key switch to one side of the coil, and ground is "thrown" by the cruise module, but on the Bobcat it is quite different. See the shematic dennis provided.
k0ua
Epic Contributor
OK, have you checked the price of the cruise module?
Yes, it is $130+ for Kioti module. I will check tonight on the starter relay voltage.
k0ua
Epic Contributor
OK, As you know the starter relay is a know weak point on these tractors, but since your gear lights don't work, I lean heavily toward the cruise module being defective.
I checked each of the three relays starting on the right side of the tractor, 70A. All showed 93.8 Ohms between the 85 and 86 pins and all clicked when 12 V was applied between 85 and 86. I am also thinking the cruise module is defective. Is there anything else I can simply test before ordering one? Is there anything the Kioti dealer can check? The module number is T4157 6___ 2 with the middle numbers scratched off
