CT335 Dead as a doornail

[Omnipotent]

Time for a new game of stump the chump....me being the chump. First off, I've scanned quite a few threads around same topic, and none of those have helped to fix the issue.

Summary: yesterday tractor worked great, used for a few hours, went to crank up this morning....dash lights come on, glow plug goes out, turn key....nothing...might have heard a pop but not positive. Turn key to off position, turn back to on, no lights, no crank, no nothing. Figure battery dead as it's a 2017...pull out battery jump starter, 200amp cranking, nothing....pull out fluke meter, battery dead as dead can be, buy new battery. Install new battery, nothing...no lights, no crank. Check fuses under instrument panel, fuse 1 (20amp blown), replace and check remainder, all good. Turn key, nothing. Move to relays on FW, only one that made sense to check is ignition switch, bench tested with 9v battery and fluke meter, gate opens/closes, good tone across terminals when power supplied....50-someodd ohms when just jumping 86/87, deemed relay good (did not swap with any other relay for testing).
Checked battery cable connections to ensure no corrosion or break in contacts, all check out. Checked voltage at starter, 12 volts, checked 60 amp fuse at starter, again...ohm/tone test across posts, all good (don't know of a better way to test this type of fuse).

So that's where I'm at now....thought about the OCP....but don't think that would control power to idiot lights (someone correct me if I'm wrong).

Any other ideas where to go from here? Several hours in and still have no clue what is going on.

Thanks

 

[winston1]

I guess you checked fuses? If you didn't, I would disconnect and clean the ground to battery cable where it grounds to tractor.

 

[Omnipotent]

Yep, all fuses checked.....I did replace battery and inspect cables....all appeared free of corrosion, tractor is under shelter when not in use, so not much corrosion.

Also, just pulled ignition/switch and tested it out....12 volts coming to switch and switch itself has continuity across all 3 posts.

Completely stumped at this point.

 

[winston1]

Long thread, lot's covered, but might be worth reading through. Tach/Electrical Issue

 

[Omnipotent]

Winston, thanks for that thread....didn't see that one in my previous searches. Unfortunately, none of the "obvious" ones have fixed my issue, was really hoping that "timing" relay was the ticket, but alas still no juice.

I see from your posting of schematics that you have the service manual...question, is is specific to only one model? ie, does it have 335 wiring diagram? I grabbed the diagrams you put up, but think they were 225's if I'm not mistaken.

Lastly, did you buy your service manual online or did you buy the actual manual? I'm leery of buying online as some of the sites seem shady, so if you did buy the PDF, if you recall where you bought it that would be nice as well.

Thanks again.

 

[winston1]

Miy manual covers CT225, 230 and 235. No electrical for the 335.

Couldn't guarantee this is a trusted sight. https://servicemanualsparts.com/pro..._content=sag_organic&utm_campaign=sag_organic

I cannot remember where I ordered mine from but I don't think it was Bobcat. They are $166 on there. Going to be pricy where ever you go.

Mine is hard copy, close to 2" thick.

 

[Omnipotent]

Winston thanks for your feedback...this used to be a more active forum....guess the shiny new rubbed away

One more question...I see in the electrical schematic (found one for the 335) they reference the Starter Relay, but it's not mentioned in the Owners Manual....just the 4 on the FW and the 6 behind the instrument panel. Any idea where the starter relay is located on your 225? Might give me an idea of where to look, because I can't find it for the life of me.

 

[winston1]

Mine is a CT235, but thinking all 3 in manual have same locations as shown here.

 

[Omnipotent]

Thanks....some things are different, because that location is my ignition relay...I think there is just some terrible language translations as the same relay's are referred differently in different text.

Oh well, I'll keep working it. I'm thinking it's a ground issue, but yet to find it. Thanks

 

[Redleafmaple]

Did you test the starter? Un hook it from the tractor and put 12v to it and see? Or the starter solenoid?

 

[BobLou]

I think its a relay.
Do you hear a clicking sound when you turn the key?
You should, relay.

Same thing happened to me on a CT235 a few years back but i cannot remember what and where that relay was.

Try to jump the starter, it should start.

 

[tman1020]

Some of the relays on the firewall are incorrectly marked in manuals. Not sure what all models are affected but My 225 is listed incorrectly as relay locations. So I would check all relays on firewall. Try swapping one around if they’re the same. There should be three of them right together

 

[Omnipotent]

I'm back and still not working....at this point I've jumped the starter and it will engage the motor. I believe the issue is my ignition switch, I've taken the switch out and tried to jump/hotwire but with no luck...mind you I did this were the ignition harness connects to the wire harness...didn't cut cables. I was trying to jump pins with a jumper cable but couldn't get it to turn over. I'm thinkin I might buy a generic 4 post switch and see if that will start it....as the ignition switch is out of stock everywhere.

Thoughts on the hotwire? Any idea why I couldn't jump the constant hot to the starter lead?

 

[Omnipotent]

I have checked all of the relays on the FW....pulled them all, bench tested them and they all test out working. I did order one of each type that are incoming just in case...but I don't "think" its a relay. The main difference with mine from others....when I turn the key I get no lights on the dash....makes me think it's either the Control Module or the ignition switch itself.

 

[dfkrug]

....makes me think it's either the Control Module or the ignition switch itself.

I have been thru this several times for a neighbor up to last year. The CT335 was getting
older and it was a former rental unit. Tough life. Neighbor has recently moved, Whew!

IIRC, the Operation Control Unit and PTO safety switch were the culprits. If it were my tractor, I would be bypassing the safeties and going to toggle switches for PTO, bypassing the control box. There seems to be an analog signal involved.

Good luck.

 

[Omnipotent]

Thanks for the input....PTO safety would affect startup but not lights on dash, at least according to the electrical schematics....from what I read, it's switched power relay, to Control Module to Dash panel. There is a pigtail off of the Ignition that sends a "start" signal to the Control Module for engine start, but don't "think" that lead has anything to do with dash lights. I've tried jumping the Ignition switch leads to no avail....which is leading me back to the module....just at $350 with no returns, I'm trying to be positive that it's the culprit.

 

[dfkrug]

Thanks for the input....PTO safety would affect startup but not lights on dash, at least according to the electrical schematics....from what I read, it's switched power relay, to Control Module to Dash panel. There is a pigtail off of the Ignition that sends a "start" signal to the Control Module for engine start, but don't "think" that lead has anything to do with dash lights. I've tried jumping the Ignition switch leads to no avail....which is leading me back to the module....just at $350 with no returns, I'm trying to be positive that it's the culprit.

Yes, we would get dash lights but the starter motor would not spin. There were years of intermittancy with the range switch, too.

I am not a fan of requiring an HST tractor to be in neutral to engage the starter. Foot-clutch safety switch not so bad, but I have disabled mine.

The Bobcat CT335 safety switch and control module scheme is different from the near-identical Kioti DK35SE, and will likely result in future trouble even if working at present.

 

[JayCat]

Yes, we would get dash lights but the starter motor would not spin. There were years of intermittancy with the range switch, too.

I am not a fan of requiring an HST tractor to be in neutral to engage the starter. Foot-clutch safety switch not so bad, but I have disabled mine.

The Bobcat CT335 safety switch and control module scheme is different from the near-identical Kioti DK35SE, and will likely result in future trouble even if working at present.

I know this an older post but...a shot in the dark here.
I had a maddening issue like that suddenly also. Checked for hours. My problem was a connection to the seat safety. I had checked & cleaned the connection under the seat but eventually found a quick connection coupler farther down the line that had pulled apart but not enough that it looked unhooked. I had put a pair of gloves behind the seat and must have pulled it apart just enough to lose contact but not enough to fully unplug the two connections.
Simple & stupid but sometimes that happens...too often for me!

J

 

[BobLou]

Hello
I had the same issue it took me a long time to figure out it was a relay.
When turning the key do you hear the relay "clik", if not I would start there, you say if you jump tge starter it starts.
So it might also be a safety switch,
One under the seat, 1 for rear PTO, one for mid PTO.

In the end I bought a new relay and started switching it on every old relay and it worked. I beleive the culprit relay was on the fire wall.

Good luck.

 

[dfkrug]

I also had a CT230, purchased new, and it had a Bobcat-specific safety control box, unlike the equivalent Kioti CK30. Similar scheme to the CT335.

Safety switches for range and foot-clutch will eventually cause problems as the tractors get older. As you say, there are also PTO and seat switches.

Checking relays by swapping them is easy, plus hot-wiring the starter will eliminate the common weak battery and bad battery cable connection problems.