cub cadet rzt 42, model 17AE2ACG010 electrical problem

[countryboy385]

Ok,

Mower has 112 hours on it, about 4 yrs old. Today while mowing the engine stopped suddenly, just as if a switch had been turned off. Mower will still crank, but not start. I pulled the plug and cranked it with the plug grounded against the enging block. No spark.

When I disengage the brake handle and attempt to crank, no cranking and the brake light illuminates.

When I turn the key on, voltage shows and oil pressure light illuminates (normal).

I have attempted to remove the seat "box" that has switches underneath it, as I'm reasonably confident it is the seat safety switch, but I have not been able to find ALL of the bolts to remove it and gain access underneath. I can reach in with my finger and push in the switches (both of them) behind the parking brake. But I have not been able to positively locate the seat switch. Every diagram I've seen is for a newer model and shows a switch that does not exist on mine.

One other possible culprit could be the ignition module. It is easy to gain access to. Is there a way to test it, and rule it out before I spend another 4hrs trying to get at the seat switch?

 

[Bob_Bainbridge]

If an interlock, like the seat, was bad it would not crank. Sounds like an ignition problem.
Bob B.

 

[OldMachinist]

On the RZT the seat switch grounds out the magneto but has no affect on the starting circuit so it would still crank if switch was bad.

 

[Bob_Bainbridge]

On the RZT the seat switch grounds out the magneto but has no affect on the starting circuit so it would still crank if switch was bad.

Makes diagnosis a little harder. Could be interlock or ignition problem.

Bob B.

 

[countryboy385]

Ok,

Mower has 112 hours on it, about 4 yrs old. Today while mowing the engine stopped suddenly, just as if a switch had been turned off. Mower will still crank, but not start. I pulled the plug and cranked it with the plug grounded against the enging block. No spark.

When I disengage the brake handle and attempt to crank, no cranking and the brake light illuminates.

When I turn the key on, voltage shows and oil pressure light illuminates (normal).

I have attempted to remove the seat "box" that has switches underneath it, as I'm reasonably confident it is the seat safety switch, but I have not been able to find ALL of the bolts to remove it and gain access underneath. I can reach in with my finger and push in the switches (both of them) behind the parking brake. But I have not been able to positively locate the seat switch. Every diagram I've seen is for a newer model and shows a switch that does not exist on mine.

One other possible culprit could be the ignition module. It is easy to gain access to. Is there a way to test it, and rule it out before I spend another 4hrs trying to get at the seat switch?

Ok, More on the saga...

after several hours of manipulation, managed to remove both switches behind the parking brake. One has 3 wires and is normally closed, but when I push it, all contacts become open. the other switch was normally open, with 2 wire connection points (3 wires -one doubled) and when I pushed it became closed. they appear to be working.

On the advice of semi-local mechanic, removed ground wire from coil, cranked with plug out and viola...sparks. Put ground wire back on and ... sparks.

while re-assembling, found broken red wire connection to bottom of carbereutor.... got excited. used butt connector and piece of wire to reconnect it and .... nuttin.

tried cranking and spraying some starter fluid into carb, motor fires briefly. So I'm suspecting fuel pump now.

What amazes me is the lack of spark when I initially started this project that suddenly began working.

Your thoughts

 

[Bob_Bainbridge]

Maybe you had multiple problems. A flaky interlock may have started working while you were troubleshooting them. After 39 years in the computer repair field I learned to never ASSUME and sometimes go back to square one again, especially after the symptoms seem to change.

Bob B.

 

[countryboy385]

you may be right about the interlock. I've checked fuel flow to the pump. good so far. will be checking pump soon (gotta disconnect output). I'll let you know

Do these vacuum pumps have issues with priming?

 

[rcbe]

shouldn't - just make sure your fuel tank cap vents are clear..

 

[Bob_Bainbridge]

I ran my 3235 out of gas 1 day, before I replaced the faulty tank sensor, and had a hard time getting it started again. I used several shots of starting fluid before the pump finally primed and started. I keep a close eye on the fuel level now.

Bob B.

 

[countryboy385]

I disconnected the fuel output hos at the carbuertor, fuel is getting to the carb just fine. So i'm pretty sure it's something inside the carb. It looks pretty easy, which concerns me because experience says it's never as easy as it looks. Disassembly tonight.