Kx161s short to ground

[Dieskyver]

Sorry if I’m rambling it’s been a long past couple of days. I’ll try to keep it as short and direct as possible.

machine ran fine when I turned it off. Two days ago. 2 hours later the switch was dead. The 50amp slow burn fuse was blown.
Next day I was able to use a test light in place of the fuse and the help of my serv manual to isolate the engine stop solenoid. Lights out when unplugged. It had no branch fuse or relay between it and the 50amp. Just a straight shot. Made sense. I figured I would be able to keep it unplugged and run the machine and disconnecting the fuel pump to kill the machine til the part gets in.
Had to go an a mission and drive to a nearby town to get a new fuse. I think it was the last one in/around the greater B’ham metro area. Plugged it in, turned the switch on this morning and it blew.
Re-Enter my in line test light. This time with the switch ON, the test light flashes in sync with 3 clicking relays and the light on the throttle knob panel blinks. Think it’s the Auto idle iirc. I started pulling fuses and all activity stopped when I reached the “meter main” 10 amp. At this point my serv manual was little help. I think I’ve got a diff model or something. Re inserted 10amp. I pulled one of the two connectors(the 22 pin not the 20 pin) hooked to the instrument panel and the activity(clicking and light) stopped again. Reconnecting panel and disconnecting the clicking relay also stops the others clicking and turns test light off AND illuminated the panel and gives me a code 11(accel sensor) and/or 12(governor). Which makes sense too I spose.
I opened the instrument cluster. No visible signs of damage to the electronics boards. It’s about $700+tax. It’s all signal wires on the instr panel connector so I wouldn’t think that would blow a 50 amp fuse??? Not sure where to go to isolate any other components and I don’t trust my manual now. Ill post more pics of the elec diagrams in a little bit. Any help is appreciated.

 

[Mark_BX25D]

I opened the instrument cluster. No visible signs of damage to the electronics boards. ... It’s all signal wires on the instr panel connector so I wouldn’t think that would blow a 50 amp fuse???

I don't know your machine, so I can only offer general help. You are on the right track. 50 amps through that circuit board would leave HUGE, very obvious damage. In fact, I would say it's probably not possible. Something would fry big time long before you blow the fuse. 50 amps is a LOT of current.

I really don't think that circuit board is your problem. Look elsewhere.

Since you have the service manual, you have wiring diagrams, correct? I suggest you scan the diagrams and print them out. (It's worth a trip to town if you don't have a scanner. Scan to a file and keep them on a thumb drive. you may want to print them multiple times. Easy if they are on your thumb drive.) Print out the diagram for the circuit you are interested in, and trace the circuit using a highlighter. This helps keep things straight in your mind. It's VERY easy to get lost in wiring diagrams.

The other thing is to WRITE DOWN what you test. You CANNOT keep it all straight in your memory. Take it slow, test one thing at a time, and write down every step and what you did and what you observed.

 

[Dieskyver]

I don't know your machine, so I can only offer general help. You are on the right track. 50 amps through that circuit board would leave HUGE, very obvious damage. In fact, I would say it's probably not possible. Something would fry big time long before you blow the fuse. 50 amps is a LOT of current.

I really don't think that circuit board is your problem. Look elsewhere.

Since you have the service manual, you have wiring diagrams, correct? I suggest you scan the diagrams and print them out. (It's worth a trip to town if you don't have a scanner. Scan to a file and keep them on a thumb drive. you may want to print them multiple times. Easy if they are on your thumb drive.) Print out the diagram for the circuit you are interested in, and trace the circuit using a highlighter. This helps keep things straight in your mind. It's VERY easy to get lost in wiring diagrams.

The other thing is to WRITE DOWN what you test. You CANNOT keep it all straight in your memory. Take it slow, test one thing at a time, and write down every step and what you did and what you observed.

Great advice. I was mentally wore out after yesterday. That will help me stay organized and systematically check all the components that run thru the circuit. I have the hard copy manual already and attached a picture in the Original Post. But it says the fuse for the panel is a 5amp. But the machine is carrying a 10 amp. The “meter sun” is a 5 amp. Also the connector layout is different. See attached pic. Thanks for the encouragement. I’ll be sure to keep updated(aka vent) documented here.

 

[Henro]

If I remember correctly what you reported in the first post, you left the fuel cutoff solenoid disconnected when you replaced that 50 amp fuse, and then observed what happened. And the 50 amp fuse blew.

The fact that your test light, that you used to replace the fuse for troubleshooting, which is a very good idea by the way, went out when you disconnected the fuel cutoff solenoid is an indication that the problem is related to the fuel cutoff solenoid somehow.

Might be time to invest in a Volt Ohm Meter (VOM). Sounds like you may have a short in your wiring somewhere. You mentioned 50 amp fuse in the OP. Was this a typo? Did you mean 5 Amps?

With 12+ volts from the battery you would have to have a resistance of less than 0.25 ohms roughly to blow that fuse. This is real close to a direct short.

Since the light you used to replace the fuse went out when you disconnected the fuel cutoff solenoid, I would be very suspicious of any wiring that you may have moved when disconnecting that solenoid.

Could be a short to the frame where the wiring harness touches, or could be a short between wires in the harness itself.

A VOM could be your friend, but the light used in place of the fuse may tell you a lot, if you put it in place and start moving the wires while watching the lamp.

Just a couple thoughts that may hopefully be of some help.

 

[Mark_BX25D]

.... it says the fuse for the panel is a 5amp. But the machine is carrying a 10 amp.

That could be the result of a previous problem being "solved" by a previous owner by putting in a too-big fuse. That is NEVER a good thing to do. Unless you have VERY solid evidence that 10 amp is correct, I'd start right there - put in a 5 amp as the manual states. If it blows quickly, you know you have a problem right there.

But to make it more fun, that won't immediately give you any idea if it's related to the other problem or if it's completely separate!

But do it anyway!

And feel free to vent away! Who knows, it may jog a useful thought in somebody reading it.

 

[GreensvilleJay]

I'd have to see a good, clear wiring diagram but 'generally' speaking...
+12 from battery goes to a large(50A for you) slowblow fuse that then feeds several smaller rated fuses that power various circuits.
If it's wired this way, the 50A fuse cannot blow if say the 10A 'work light' gets shorted to ground. The 10A fuse blows.
However.. if the COMBINED current being drawn by 'devices' exceeds 50 amps THEN the 50A slowblow will blow. Say there's 6 fuses, and each are rated for 20 amps, if 5 of them are drawing 11 amps, the main 50A fuse will blow, as the combined current is 55 amps
Now IF all the wiring is original, you shouldn't have a problem but if someone's added ,say extra worklights,radio, etc. you might have a combined draw of over 50 amps...
If you have a good DMM that can read 20 DC amps, pull all fuse out but not the 50A main. Install a BLOWN fuse into one position, put meter leads on the exposed contacts of the blown fuse, and read the current being drawn.Obviously the 'worklight' or pump' or whatever needs to be on.
Make a chart and record what you get. Typically you'll have a 10A fuse for an 8 amp load, 5A for 3 amp.
Add up the total and see what you get for real loads.
Mark is 100% correct. Always replace blown fuse with the CORRECT rated one, according to the manual or fuse block data.

 

[Dieskyver]

If I remember correctly what you reported in the first post, you left the fuel cutoff solenoid disconnected when you replaced that 50 amp fuse, and then observed what happened. And the 50 amp fuse blew.

The original blown 50amp fuse problem was the cutoff solenoid. i disconnected it and totally removed it from the system. then blew the same fuse again.

The fact that your test light, that you used to replace the fuse for troubleshooting, which is a very good idea by the way, went out when you disconnected the fuel cutoff solenoid is an indication that the problem is related to the fuel cutoff solenoid somehow.

ill have to give youtube credit for the idea. it is brilliant. i dont think the solenoid is related directly anyway. its a pretty straight forward. the new one should be in early this week along with 5 new 50 amp fuses

Might be time to invest in a Volt Ohm Meter (VOM). Sounds like you may have a short in your wiring somewhere. You mentioned 50 amp fuse in the OP. Was this a typo? Did you mean 5 Amps?

With 12+ volts from the battery you would have to have a resistance of less than 0.25 ohms roughly to blow that fuse. This is real close to a direct short.

Since the light you used to replace the fuse went out when you disconnected the fuel cutoff solenoid, I would be very suspicious of any wiring that you may have moved when disconnecting that solenoid.

This is what i was thinking too.

Could be a short to the frame where the wiring harness touches, or could be a short between wires in the harness itself.

A VOM could be your friend, but the light used in place of the fuse may tell you a lot, if you put it in place and start moving the wires while watching the lamp.


i call it my mexican multimeter, i stole that term for an amigo of mine btw,

Just a couple thoughts that may hopefully be of some help.


Thanks for the input. i drove out to y brothers yesterday and retrieved a power probe ect3000 so it is official. My tools are smarter than me. I havent had time to play with it much but it does indicate an OPEN circuit. due to the tight space it can be difficult to isolate a wire in the bundle of wires.

with the key on and in the lamp in place of the 50 amp, i can pull one of the clicking relays and get all the activity to stop and a message on the instrument panel saying accel sensor. I think it might be related to the auto idle i havent found out much about it yet. thanks again

 

[Dieskyver]

If I remember correctly what you reported in the first post, you left the fuel cutoff solenoid disconnected when you replaced that 50 amp fuse, and then observed what happened. And the 50 amp fuse blew.

The fact that your test light, that you used to replace the fuse for troubleshooting, which is a very good idea by the way, went out when you disconnected the fuel cutoff solenoid is an indication that the problem is related to the fuel cutoff solenoid somehow.

Might be time to invest in a Volt Ohm Meter (VOM). Sounds like you may have a short in your wiring somewhere. You mentioned 50 amp fuse in the OP. Was this a typo? Did you mean 5 Amps?

With 12+ volts from the battery you would have to have a resistance of less than 0.25 ohms roughly to blow that fuse. This is real close to a direct short.

Since the light you used to replace the fuse went out when you disconnected the fuel cutoff solenoid, I would be very suspicious of any wiring that you may have moved when disconnecting that solenoid.

Could be a short to the frame where the wiring harness touches, or could be a short between wires in the harness itself.

A VOM could be your friend, but the light used in place of the fuse may tell you a lot, if you put it in place and start moving the wires while watching the lamp.

Just a couple thoughts that may hopefully be of some help.

The lamp idea I got from YouTub

That could be the result of a previous problem being "solved" by a previous owner by putting in a too-big fuse. That is NEVER a good thing to do. Unless you have VERY solid evidence that 10 amp is correct, I'd start right there - put in a 5 amp as the manual states. If it blows quickly, you know you have a problem right there.

But to make it more fun, that won't immediately give you any idea if it's related to the other problem or if it's completely separate!

But do it anyway!

And feel free to vent away! Who knows, it may jog a useful thought in somebody reading it.

Thats an idea. i tell you what its just erupting with fun over here lol. The fuse cover on the machine indicates a 10 amp for the circuit tho. i think the wiring is all original. the manual that came with the machine is for a slightly different model i think.

 

[Mark_BX25D]

The fuse cover on the machine indicates a 10 amp for the circuit tho. i think the wiring is all original. the manual that came with the machine is for a slightly different model i think.

I'd go with the fuse cover on that.