Countax Electrical Problem

[Joc]

Hello, and thanks for reading.

I have a 2006-2007 Countax C600H (Honda engined V-twin) ride-on lawn tractor with manual deck height adjustment (not HE).

It's designed not to start unless the handbrake is on, to stop the engine if not sitting on the seat unless the handbrake is on, and to stop the cutter deck when not sitting on the seat.

While mowing Last week, the engine stopped, and will only restart for about a second before immediately cutting out.

I would be grateful if someone could help identify the cause of that.

The PCB including relays are fully sealed in some kind of resin. I assume the PCB controls the interlinked safety switches.

The engine starter switch and cutter deck switch are non-latching, so I assume they each operate a relay.

The battery is fully charged; the -ve ground is good (12V between battery +ve and rocker cover bolt) and there is fuel in the carburettor. The two 20A and three 10A fuses are all intact.

Any fiddling I have done has been after the problem happened.

If I disconnect the engine stop diode from both coils, the engine starts and continues to run, on both cylinders, although the cutter deck won't engage (no relay click nor clutch activation click when press cutter switch).

Hence I don't believe a coil is faulty, and I don't believe the cause is lack of fuel. To be sure, I clamped the fuel cut solenoid in retracted (open) position.

I assume when turning off the ignition switch, the engine stop diode short circuits the coils, preventing sparking.

I replaced the engine stop diode with a new one, but that made no difference.

Two wires are connected to the ignition switch; I tried bypassing the ignition switch using copper wire between its connecting wires, but that made no difference.

The seat safety switch is working, and the handbrake safety switch is working.

I temporarily connected the electro-magnetic cutter deck clutch directly to the battery: the clutch activated briefly. There is another diode fitted between the two wires of the clutch, possibly to prevent damage from spike when clutch is de-magnetised, so I don't want run it without that.

I don't have a circuit diagram for my exact PCB, 44-80170 (last digits, if any, have rubbed off label). I have a circuit diagram for the nearest numbered PCB to mine, downloaded from a Polish website.

[Mick]

Hi Joc, and welcome to TGMForum.

It's sounding more and more likely to be a circuit board issue.  I didn't work on these as much as my brother and he had a whole load of known working boards which he kept just for testing.  Unfortunately when you don't have test boards it can be a rather expensive gamble to see if a new board cures it.

There is a Countax group on facebook which might be helpful.  Countax / Westwood Mower Owners - tips, advice, spares. UK. https://www.facebook.com/groups/1143907236785561