Scag STC-48 starting issue

[Hammer Head]

My Scag ZRT STC-48V-26BS would not start, so I tried to arc the poles on the solenoid. It fired right up, so I replaced the solenoid with no change, same issue.
Next I changed the ignition switch, that did not fix the issue. I can still start it by arcing the solenoid.
Any ideas what next??

 

[jimmysisson]

You hit both ends, now look for a weak or broken wire between the switch and solenoid. Do you have power at the solenoid from the switch in start position?
Jim

 

[EddieWalker]

I don't know your model, but my Scag Wildcat has been giving me issues with starting lately. At first I thought it was a dirty terminal on my battery because nothing happened when I turned the key, but my volt meter said I had 12.6 volts. I cleaned the terminal and it fired right up. Then a week later, nothing happened when I turned the key. Battery terminals looked great. I followed the path of power and everything seemed to be working. I checked every safety sensor with good results. Then I tried to start it again and it fired right up. Third time it happened I just focused on the safety buttons. Parking break didn't seem to be pushing it in all the way, so I pushed it in all the way with my finger and it fired right up. This last weekend it wouldn't start and nothing worked. 4 hours later, I spliced in a wire from the hot terminal on the water temperature gauge and another onto the blue wire with the white stripe off of the switch that goes straight to the starter solenoid. Both wires are hanging freely, and when I turn the key and touch the ends of the wires together, it fires right up.

I'm guessing the problem is the relay next to the key. I hate buying parts hoping they will fix it, but nothing is making any sense to me so far.

Eddie

 

[Hammer Head]

Eddie,
All of my safety switches check out ok and wiring also. My dealer is 45 min. away and he says the only way he can help is to bring it in. I work 5 days and have personal rental properties, house and camp to mow on my time off.
I also hate replacing parts by process of elimination. the only good is I have an inventory of parts now. I think the only thing left is the starter or interlock?
I have a local starter/alternator rebuild shop that I may take it to. They may know something that I am missing. I am fairly good with mechanical repairs, electrical is my weak point. No sure of the relay on my model?
I will let you know once I nail it down.

Jeff

 

[lcuinc]

I've just been through a similar issue with my scag. What engine so you have? Have you checked fuses? Mine wouldn't start and I assumed corrosion so cleaned battery. Still wouldn't start so jumped and started right up. Ran until I removed the jumper cables. That's when I found blown fuse. Research made me think it was the stator but I torn engine apart and it was fine. Long story short, some models had a problem with the ignition system and diodes. There is a conversion kit to get rid of problem system. Let me know what engine you have and I can see if it could be.

 

[Hammer Head]

My Scag has the 26HP Briggs.
Fuses are fine, Battery is new and terminals are clean. All of the safety switches check out and work. I have a new ignition switch and solenoid.
It will start just fine by arcing the two poles of the solenoid! When I turn the key to the first (run) position I hear a click in the starter, so power must be getting to the starter just nothing when I turn the key to start.

 

[RandyT]

Your problem sounds like a safety switch problem, could even be the seat switch. If not the switches, then could be the interloc module.

 

[EddieWalker]

Are you sure you are hearing the click in the starter? I thought I was too, but with the seat up, I couldn't be sure and felt the starter and didn't feel anything. I then touched the voltage regulator and that's where the click was coming from. It's a sealed, black plastic looking thing attached to the fender with all the wires going into it. I had to look in the manual to figure out what it was.

I'm still not convinced my problem isn't one of the safety switch push in things. My next choice is the pull out thing to engage the mower blades. And there was some thought as to the relay. Did you take off the metal panel that the key and temp gauge is on? The relay is on the underside of that panel. If I buy anything, that's probably going to be the first thing I replace.

I have the Kawasaki water cooled 26hp engine.

The starter was a real pain to remove. I had to take off the bracket that holds the oil cooler on to get to it, and then it was a tight fit to get it out of there. I tested it with my battery charger and at first thought there was a problem. The gear popped out to engage, but didn't turn. Then I realized that it was going out so far that it was sticking on the housing. I used some needle nose pliers to stop it from going out so far and it worked fine. That was a big waste of time!!!!!

Eddie

 

[Hammer Head]

Eddie,
The click is in the Carb. I believe it is the fuel valve. I unplugged all of the safety switches and checked them again, seat switch also. they all check out ok.
The block you are talking about is the interlock or electronic module. The other is a relay.
That's what I am down to. Guess I will take it to the dealer!!

 

[Poopdeck Pappy]

Before you take it to the dealer, be sure it's not just a bad relay. If it is, it could be a $5.00 fix. I had a motorcycle once that had a similar problem that nearly drove me crazy until I finally figured out it was a $9.00 relay. It was an easy fix; the diagnosis is the maddening part.