Toro Titan 52" Commercial Zero Turn 2 Starter Solenoid Failures?!?!?!?

[Blaine B.]

My Father has had a brand new Toro Titan HD 1500 (model number 74451) 52" commercial zero turn in his possession since 2018. He only uses it in a residential capacity mowing probably less than 1 acres of grass. Last October in 2021 I replaced the starter solenoid with another brand new Toro unit (Toro part number 117-1197.) Today he tells me the mower won't start again, only getting clicks. I tell him to give the solenoid a few light taps, and that worked. What in the heck is going on with these starter solenoids and is this a common problem for Toro OEM parts? If so, what is an aftermarket part you'd recommend that isn't as failure-prone as the Toro solenoid in question? Thanks. PS - this Toro has only about ~60 run hours on it presently. Super low as it's a commercial mower used in residential capacity.

 

[mechanic mark]

Parts | Toro

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Parts – 52in TITAN HD 1500 Series Riding Mower | Toro

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I agree with Rivets, try moving ground wire by hand.

 

[Rivets]

I’m betting that the ground wire going from the solenoid to the chassis is loose or dirty. Trace this wire and clean and tighten the connection make sure you have a good ground.

 

[Blaine B.]

I’m betting that the ground wire going from the solenoid to the chassis is loose or dirty. Trace this wire and clean and tighten the connection make sure you have a good ground.

Next time I'm there I will take a look at the ground wire although I don't recall anything being loose last year. Also the mower has been used quite a few times this year and perhaps there have actually been two solenoid failures this year if I recall him mentioning, I believe earlier in the year he had an issue where he is getting clicks only.

I should also mention that I replaced at the beginning of last year in March 2021 as it seemed to have died a premature death. I remember posting about that here as well and it was mentioned by some members here that the original battery was underpowered with too low of cranking amps. I "upgraded" to maybe what should have been in the mower. Although that brings back more memories. My Father mentioned when the Toro dealership delivered this mower in 2018 that upon arrival the battery was "dead" and they had to go back to the shop to swap it out. There's a possibility that the delivery guy re-installed the wrong battery (ala too low cranking amps) and/or maybe the battery wasn't dead at all and it was a solenoid issue from day 1??!??!? Who knows, that's going on 4 years.

 

[Rivets]

To me unless you are living in the north where temperatures can get cold, a battery with low CCA shouldn’t be a problem. You might have a charging system that is not working properly, shorting the life of the battery. This will reduce the voltage available at starting, which will show up as the solenoid only clicking. Next time you start the unit attach a volt meter to the battery and read starting voltage. It should not drop below 10 VDC. If it does your battery is not holding a charge. After you get it started, read charging voltage. It should read between 13.2-13.6 VDC. If it does not your charging system may be bad. Do both of these tests after you have cleaned both of the ground connections I previously mentioned.

 

[MParr]

Toro safety switches are usually the main culprits in this situation. The parking brake switch, seat switch, and steering switches.

 

[Blaine B.]

Toro safety switches are usually the main culprits in this situation. The parking brake switch, seat switch, and steering switches.

I understand, when a safety switch is engaged it does not send power to the solenoid, no click or clunk at all.

 

[Rivets]

Blaine you are correct, that’s why I suggest voltage tests and bad connections.

 

[Blaine B.]

Blaine you are correct, that’s why I suggest voltage tests and bad connections.

Plenty of "whoopsies" on this Zero Turn as the transmission levers must be disengaged, parking brake on, and butt on seat in order to start. Or if you engage the parking brake with transmission levers engaged it will also kill the motor. But then again no clunk heard from solenoid under these "safe" conditions.

Moreso the old solenoid livened up when I gave it some taps myself. And as he had to give the new solenoid a few taps the other day to liven it up. I suppose the taps could be seating a poor connection but there is absolute zero rust or corrosion on this lawn mower anywhere. Stored indoors and only washed twice! Unless I find something very unusual at this grounding location (I doubt I will) I guarantee you that the electrical connections at the solenoid itself are tight and pristine. I evaluated them just last October 2021 when the solenoid was replaced.

 

[Blaine B.]

Here's a thought;

I believe this solenoid may be grounded via the mounting bolts. The smaller wire on the lower studs is from the ignition switch only. I believe there were only 3 wires from memory, the 2 large gauge between starter and battery and then the low amperage connection between solenoid coil and ignition. There was no corrosion between coil and body of zero turn.