Safety Interlock Defeating me

[jgarvas]

Solved: My problem was the gray tiny plastic 2 pin connector that connects to the seat safety switch. Mine is equipped with a spring loaded center piece that apparently causes the two wires to short (to ground). Every time I released the parking brake the mower acted as if nobody was in the seat. Photo here

I have a RZT Z-Force 50" from somewhere in the 2008-2009 time frame. It has no model numbers or identifying information because it was a damaged item factory sale that has worked great since the day I brought it home. I am trying to troubleshoot the safety switches, not defeat them.

Yesterday I started it and drove it down my driveway about 5-10'. I can't remember if this happened before or after I engaged the blades, but the mower completely shut off as if one of the safety switches wasn't being complied with. Now, I can turn the engine on, but the moment I try to release the parking brake the engine cuts out. Both arms are fully seated against their switches and I was sitting on the chair, PTO disabled.

I've attempted to troubleshoot this with a meter. This is what I can tell so far. The switch under the seat appears to be operating fine. It is normally closed and breaks the circuit if I push down on the seat. If I put a meter on each leg of that two pin wire I noticed that both sides have continuity to ground.

I suspect this means when seated, a ground loop is created. When you stand up, that ground is broken.

I've taken both sides of the mower apart and have cleaned out every connector with contact cleaner. I believe the arm neutral switches are working because if I move either arm in while the engine is running and the parking brake is applied, the engine shuts off.

Every schematic I've read implies there are three relays somewhere. I distinctly remember hearing a click every time I would sit in the chair of the mower and I've always assumed it was a relay. I can't find any relays anywhere. There are none near the pto/keyswitch/hour meter, there are none on the other side by the throttle either. I removed the battery and stuck my phone into the cavity and there are no relays inside there either -- just a connector for the parking brake switch.

I'm curious if anyone can help me determine what and how to check next, or if someone can tell where the relays should be? I was suspecting a relay was failing, but now I am starting to wonder if this model has no relays and the intelligence is somehow integrated into the Kohler engine under its lid. There is a bundle of cable coming out of the engine that plugs into the wiring harness and so far as I can tell the solenoid is at the engine, not on the mower's frame.

I can't get my iPhone pics to shrink down to a reasonable size so feel free to poke around the three photos here to get an idea of which zero turn this is: https://garvas.org/files/mower

[R Bedell]

First, welcome to OCC..........

Without a Model number, it will be difficult to render any advice other than general.

but the moment I try to release the parking brake the engine cuts out.

I would be looking in that area or circuit. Cut wire, disconnected wire, etc. The images you made reference to, shows A Kohler engine. I really believe, you issue is a Cub Cadet Chassis issue, NOT an engine issue.

Post some pictures of the Lawn Mower itself.

[jgarvas]

Originally Posted by R Bedell

Without a Model number, it will be difficult to render any advice other than general.

I'm thinking its a 2006 to 2008 RZT Z-Force 50" but yes, getting a model number will be near impossible. Under the seat it is painted "Not for resale" and when I took it to the shop last summer to get the deck repaired they couldn't find any identifying plates on it to indicate what model it was.

I would be looking in that area or circuit. Cut wire, disconnected wire, etc. The images you made reference to, shows A Kohler engine. I really believe, you issue is a Cub Cadet Chassis issue, NOT an engine issue.

I would think its in the electrical harness too. I guess I'm hoping someone can look at the photos and has an idea of where the relays may be? I simply can't find any relays at all, but the harness plugs into the engine so it had me wondering if the safety switches are somehow just interrupting the solenoid and there are not the typical relays for seat, brake, pto, etc?

Is there a trick to inserting photos in the forum from an iPhone without having to edit them down to 400x400 pixels?

[R Bedell]

Is there a trick to inserting photos in the forum from an iPhone without having to edit them down to 400x400 pixels?

IF.....you can not down size your photo to 450 x450 pixels, than 3rd party software can (ie: Irfanview).

The reason the pixel limit is that there are members in rural areas that don't have a very good ISP connection (speed), and large pictures take a long time to download and view.

Post you pictures to that host site in the prior post.

[spndncash]

I have three of the rzt 50's ( well one is a 48 fab deck but still the same system).
try for a factory number a 53AA5B7P712 looks like a 23/50 RZ KOH
1.parking brake safety
2.two steer lever safeties (one on each side)
3.seat safety
4.there is a deck blade safety but it is built into the blade actuator switch
5.two reverse safeties that cut out the blades when you are backing up but blades come back on after you stop reversing. (my john deere 235's you must either hold the PTO switch up or reset the switch after reversing)
I am not telling you to disable them but you can trouble shoot them by bypassing each one until you get the problem isolated. then replace that switch. I have all my safeties still installed on my ZTR's- the tractors are a different story.

And Check your grounds...

[jgarvas]

Using this schematic I have checked every single arm neutral switch both of the reverse switches the PTO and the brake switch and everyone of them is performing exactly as it should.

I made the mistake of trying to bypass the hourmeter and apparently it didn’t like that and blew the fuse haha woops.

Does the hour meter look critical to being able to disengage the brake or is that just me?

I’m not sure what else I can rule out or test.

[jgarvas]

This is the actual mower. It has to be a 2006 or later based on the manufacture date on the Kohler engine:



This is the rider's right hand side handle disassembled. In here is the neutral switch for the right arm, the key switch, the PTO button, and the hour meter. This is everything coming out of the wire loom. There were no relays anywhere to be found here:



This is what it looks like under the seat. The gray wire plugs into the seat safety switch you can see under the seat. That switch appears to test functional for me. The "not for resale" is because I purchased this damaged directly from MTD's warehouse sale years ago.

Note I have taken the battery out earlier today and taken a bunch of pictures inside the "cavity" of the mower. There are no relays in there, just a single wire loom cable that goes to the parking brake switch sensor. It DOES have multiple pins in it which do make me wonder if the switch is bad, but I'm not sure how to test that with a meter (ie: what to expect from each pin)



This is what it looks like from the rear and right side of the engine looking towards the seat. I took this to show there is obvious wire loom (and the fuse) going up along the right side of the frame to the previously shown controls. The wire loom going down appears to go to the clutch to engage or disengage the blades.



I took this to show the wire harness coming out of the Kohler Command 23 engine. I believe the red wire coming off the battery goes directly to the solenoid, which is a part of the engine itself.



This is the harness connector opened up. There are a total of five pins in this connector. I am starting to wonder if the safety switches are some how causing the kill switch in the engine to get activated, instead of using relays?



Finally, the is the left side control panel - I did have this taken apart yesterday but there was nothing electrical in here other than the idle switch and the reverse switch.



Should there not be three relays on this mower somewhere?

[R Bedell]

I "think" you have a RZT50. They were made from 2005 to 2009. In 2008, the RZT had a Kawasaki Engine, ruling that out. So, that would leave 2006, 2007, and 2009 models. Looking at 2006 & 2007 wiring diagrams to see NO Relays.