Gravely safety interlock switches

[flightdeck]

Have a Gravely ZT42XL zero turn thats been painless for 6 years..just oil changes.
Recently I've been on parts replacement duty with a new Ignition switch, which finally secured me a second key,,
and a new red knob blade engagement push/pull switch.
All was well for several weeks of attacking my winter rye on almost an acre of grass.
This week it seems that the parking brake interlock safety switch failed,,,, I hate to assume,, but:
I can start the motor with the brake on but it quits when the parking brake is selected off.
I bought a new identically part numbered interlock safety switch from HD Switch, installed it, and now the engine won't even start.
Put the old switch back on and the motor runs but I'm back to line 4..can't release the parking brake.
Anyone have a better parts place - I won't rule out that the new switch isnt the correct part even though it looks the same...or is a dud, yet.
I haven't tossed cash into a new driver seat safety switch yet either..its been working fine prior to the above event.
Is there something else mechanically attached to the parking brake linkages that interrupts the engine or am I on the right track ?

 

[bertsmobile1]

All those switches are very simple NO ( open circuit with the plunger out ) which is what yours should be or NC normally Closed with the plunger all the way out
Original switches are usually different colours but the after market ones look identical .
Your problem however will most likely be the seat switch.
Power goes from the red wire to the brown wire at the key switch when the switch is in the Start position.
It then passes through the PTO switch changing colours to Brown+Yellow. which is NC
Then passes through the parking brake switch changing colour to Brown + White. which is NO
from here it energises the the starter solenoid
So if it does not crank, pull the plug off the back of the key switch & jump red to brown
Engine cranks = faulty key switch
Then pull the plug off the back of the PTO switch & jump Brow to Brown / Yellow.
Engine cranks = faulty PTO switch
Finally pull the plug off the brake switch & jump brown/ yellow to brown / white
Engine cranks = bad brake switch

If it still does not crank jump the red directly to the Brown / white terminal on the starter solenoid
Solenoid klacks = wiring along the brown wires .
Solenoid does not Klack = bad solenoid ( includes poor ground connection )
Use a heavy jumper to go battery + to the starter motor
Starter spins = bad battery cables
Starter does not spin = bad starter or ground cable
Final test is to jump battery - to engine
starter cranks fine = bad ground strap
Starter does not crank = bad battery

To confirm bad battery do the final two jumps off our car, truck or with a known good battery .
All of the brown wires should show battery voltage is their connections are good .

ou will find the wiring diagram in the back of the parts list, a free download from Gravely .

 

[flightdeck]

All those switches are very simple NO ( open circuit with the plunger out ) which is what yours should be or NC normally Closed with the plunger all the way out
Original switches are usually different colours but the after market ones look identical .
Your problem however will most likely be the seat switch.
Power goes from the red wire to the brown wire at the key switch when the switch is in the Start position.
It then passes through the PTO switch changing colours to Brown+Yellow. which is NC
Then passes through the parking brake switch changing colour to Brown + White. which is NO
from here it energises the the starter solenoid
So if it does not crank, pull the plug off the back of the key switch & jump red to brown
Engine cranks = faulty key switch
Then pull the plug off the back of the PTO switch & jump Brow to Brown / Yellow.
Engine cranks = faulty PTO switch
Finally pull the plug off the brake switch & jump brown/ yellow to brown / white
Engine cranks = bad brake switch

If it still does not crank jump the red directly to the Brown / white terminal on the starter solenoid
Solenoid klacks = wiring along the brown wires .
Solenoid does not Klack = bad solenoid ( includes poor ground connection )
Use a heavy jumper to go battery + to the starter motor
Starter spins = bad battery cables
Starter does not spin = bad starter or ground cable
Final test is to jump battery - to engine
starter cranks fine = bad ground strap
Starter does not crank = bad battery

To confirm bad battery do the final two jumps off our car, truck or with a known good battery .
All of the brown wires should show battery voltage is their connections are good .

ou will find the wiring diagram in the back of the parts list, a free download from Gravely .

Great intel, Thanks !
Its a B tracking down the seat safety switch...son't see it in Gravely parts manual for this mower.
Good battery, found out solenoid is built into starter..still works.
Was R&Ring it with ignition & PTO. Time to cxl and buy local if able.
The seat switch faulted a couple of years ago but has played nice since. May as well change it out too.
Unfortunately, due to life, the ZT was evicted a yr ago from garage to concrete pad under the deck.
24/7 ability for the wx to trash contacts/switches. Using WD40 on occasion but don't wanna get them gummy to hold dirt etc.
Thx again !

 

[sgkent]

use DeoxIt spray on contacts instead of WD40

 

[flightdeck]

Appreciate it. Still looking for the dang seat switch PN. Guess I'll call gravely Tuesday...