This is a summary of the history of the fault on my old Countax C600H garden tractor. I have a very short video that shows the current situation. If I could upload it you would hear a buzzing noise coming from the digital display on the PCB when I turn the ignition to the crank engine position. That is all that happens. Note that when the ignition is turned to the on position the digital readout is normal ie. park brake, hours, and cutter off are displayed.
History of events:
Get dreaded clicking noise from starter not turning engine.
A few hours later it starts and I cut the grass.
Following morning mower won't even attempt to crank engine, just get buzzing noise from display on PCB - as in video.
Discover 20amp fuse on CHARGE circuit has not blown but the plastic had melted.
Here is a copy of the electrical circuits with the CHARGE circuit circled.
I have checked the battery voltage - good at above 12.8
I have checked engine and components all have grounding continuity.
I have bench tested ignition switch and starter motor - both good.
The seat and brake safety switches test good.k
Unsure about rectifier/regulator this is as far as I've got as I live in the Highlands of Scotland and can't find anyone who has a rectifier/regulator (R/R) testing machine. It's a Honda component and very expensive:
The number stamped on the Honda regulator is SH621-12. However the latest part number per the Honda website is 31620-ZG5-033 (20A) and it has the stamp SH711AA on it? The modern wiring colours are different. Here is a photo of mine with a note of the colours going to the six spade terminals:
Top from left to right - white, black/white, black
Bottom from left to right - grey, blue/white, grey
When I test with my multimeter in the diode setting I only get readings when my positive probe is attached to the top right spade and I run along the three bottom spades with The negative black probe. The readings from left to right are 492, 1520, 492. This high centre spade reading would normally indicate a bad diode, but because it does not have a grey wire going to it like the other two terminals, I'm not sure if it is actually a diode connection? All other readings when the probes on the meter are reversed are 1.
Although I get battery voltage to the starter motor/solonoid something is stopping the engine being cranked. I have a new PCB but I'm anxious about trying it in case some other fault might damage it. In particular - until I know that the rectifier/regulator is good. However, my thinking is that the engine should start even if the R/R is faulty and that the PCB is stopping everything from starting?
All help gratefully received.
Iain
History of events:
Get dreaded clicking noise from starter not turning engine.
A few hours later it starts and I cut the grass.
Following morning mower won't even attempt to crank engine, just get buzzing noise from display on PCB - as in video.
Discover 20amp fuse on CHARGE circuit has not blown but the plastic had melted.
Here is a copy of the electrical circuits with the CHARGE circuit circled.
I have checked the battery voltage - good at above 12.8
I have checked engine and components all have grounding continuity.
I have bench tested ignition switch and starter motor - both good.
The seat and brake safety switches test good.k
Unsure about rectifier/regulator this is as far as I've got as I live in the Highlands of Scotland and can't find anyone who has a rectifier/regulator (R/R) testing machine. It's a Honda component and very expensive:
The number stamped on the Honda regulator is SH621-12. However the latest part number per the Honda website is 31620-ZG5-033 (20A) and it has the stamp SH711AA on it? The modern wiring colours are different. Here is a photo of mine with a note of the colours going to the six spade terminals:
Top from left to right - white, black/white, black
Bottom from left to right - grey, blue/white, grey
When I test with my multimeter in the diode setting I only get readings when my positive probe is attached to the top right spade and I run along the three bottom spades with The negative black probe. The readings from left to right are 492, 1520, 492. This high centre spade reading would normally indicate a bad diode, but because it does not have a grey wire going to it like the other two terminals, I'm not sure if it is actually a diode connection? All other readings when the probes on the meter are reversed are 1.
Although I get battery voltage to the starter motor/solonoid something is stopping the engine being cranked. I have a new PCB but I'm anxious about trying it in case some other fault might damage it. In particular - until I know that the rectifier/regulator is good. However, my thinking is that the engine should start even if the R/R is faulty and that the PCB is stopping everything from starting?
All help gratefully received.
Iain
