ZD28 starting problem

[dc350]

Have a ZD28 with a 72" Pro deck with less than 500 hours. Bought used and worked well last season. Started having sporadic issues starting it this year and has consistently gone down hill.

Clues:

1. Started with inconsistent starting. Sometimes would fire right up, sometimes would take 5 or 10 minutes to engage.
2. Fuel gauge stopped working correctly. Full tank will only register 1/4 full but does drop from there as diesel is consumed. (May be totally unrelated).
3. Replaced the battery...no change. (grrr...)
4. Can start the mower instantly by shorting between the starter post and the small spade connection...but...
5. NONE of the safety switches work. I can start it with the PTO engaged, the parking brake off, the drive levers in any position and the seat empty. Kind of scary...

Anyone have any idea what may be causing this? Bad control module perhaps?

Many thanks!

dc

 

[meanjean]

Clean every battery connection/ground on the tractor.
Did the fuel gauge problem start at approximately the same time as starting problems? Likely unrelated but who knows? Electrical gremlins are little buggers that way. Might as well fix that for peace of mind.
None of the safety switches working is a whole other headache!
I sure hope it's not a bad module, sounds expensive!

 

[ShaunRH]

Test each switch, this could be part of the issue with starts. Shorting the solenoid is only demonstrating that you have a working solenoid!

Get the schematic for the unit and test all switches and wires from point to point. This should find any opens or shorts that may be causing you problems. Wiring does rub and lose insulation and short out, causing issues like you are experiencing, but then again, a faulty safety switch might as well.

In all likelihood, the previous owner bypassed the safety stuff and the bypass could be causing problems...

I don't know how the fuel gauge works on that unit but if it's float based, it could be a bad float (fuel logged) or a bad sender.

 

[dc350]

Thanks for the responses! Sounds like I have some investigative work to do...

As an aside, the safety functions all worked last season so I don't believe anything was bypassed. I'm starting to wonder if there is a common ground that has gone bad.

 

[dc350]

Believe I have resolution!

Tested the trigger wire that attaches to the starter and was pulling 11.5 volts...a little low but not bad. And I think that I had a bad or dirty connection between the lug and the spade on the starter. Pulling it on and off may have improved it as the mower starts perfectly now.

In all likelihood, the previous owner bypassed the safety stuff and the bypass could be causing problems...

I stand corrected...as I thought more about this I figured out that I had always done the proper procedure for getting off the mower and leaving the engine running...turned off the PTO, set the brake and the arms, etc. So I really didn't know if the safety switches were working correctly.

So I pulled up the seat and lo and behold the seat switch is disconnected and the male side is jumpered. So that's why none of the safety switches work when you get out of the seat. Don't yet know if it's a bad seat switch or a mod that the previous owner for convenience (although I suspect the former).

Thanks again to everyone for their input...much appreciated!

dc