LX565 Intermittent Starting Problem

[markplow]

I have found lots of similar posts on here to my problem, but have not been able to resolve the issue. I have seen reference to a thread called "LX665 Won't Start", but can't seem to find this exact thread for some reason.
Here are the details. - LX565 ~1994 - Intermittently will not crank when key is turned to start position. Relays click , but starter does not engage. - Switch to service mode and it starts every time. If started in service mode and then switched to run mode with the engine running, the engine dies. Is this normal? -
Audible clicking, seat belt light going out on dash and several multimeter checks suggest that the seat/seat belt interlocks are working. - Interesting observation... When I sit in the seat and put the seat belt on, the "fasten seat belt" icon on the dash goes out. When I turn the key to the start position though, the "fasten seat belt" icon illuminates. It acts like when it is in the start position the seat/seat belt interlock is "dropping out".
When the "fasten seat belt" icon illuminates it also locks the control pedals (i.e. key on, engine not running, = pedals move freely. Turn key to start position and hold (assuming engine does not start), and the pedals lock)
It's like the logic fails for some reason in start mode, but not in key-on mode. Could there be a big voltage drop somewhere causing this.....??? - We have replaced the start interlock relay and this made no difference. Actually my dad replaced all the relays in the engince compartment panel just to be sure and it made no difference. - We jumped across the starter switch (just to make sure there was not some crazy voltage drop acrossed it) and got the same results. -
To me I can't see how it is any of the following that is the problem -
Starter - starts fine in service mode -
Ignition Switch - Same result when jumpering across it -
Seat Switch - audible clicking of relay when this switch contacts -
Seat Belt Switch - audible clicking of relay when connected + icon goes out on dash - Interlock Relay - audible clicking, plus already replaced
I saw a post saying a similar problem turned out to be the "service/run" switch. I'm digging into that now (don't have one to just change it out). To me the issue is being caused by the operator presence interlock circuit "opening" when you turn the key to the start position. I don't understand the circuit enough to see what the connection could be between these two activities.
Of course I could always go with the standard "replace the EIC" fix, but my experience tells this is often not the real issue... plus it is expensive.
For reference, I worked for NH in the past and got to work with the group that evaluated what was wrong with all the EIC's that were sent back. The VAST majority of the EIC's had no problems with them. In my hands-on experience (working with customer and test machines at NH) I have never found an issue that actually turned out to be this EIC (not to say that it never happens....).
Any thoughts on where to go with this? Thanks in advance for any help you can provide. Mark

 

[skidsteer.ca]

Mark
First go here http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=EditUserProfile and put a check in use "free html editor" and you will have paragraphs that work. I edited your post (hopefully to you liking) so its easier to read.
Do you have a copy of the NH manual showing the circuits?
If not you can download one for a 160/170 here (hopefully the same) http://www.mediafire.com/?ux89bq2u4u3ug
Look at the the circuit diagram for the start with and without the bypass switch on. It is either something in that circuit, most of which you have tested, or
Some key switches have two power on terminals on the back but only one stays energized during while the key is in the start/crank position. and pehaps that is where you get the current interuption from.
Let us know how you make out.
Ken

 

[markplow]

Mark
First go here http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=EditUserProfile and put a check in use "free html editor" and you will have paragraphs that work. I edited your post (hopefully to you liking) so its easier to read.
Do you have a copy of the NH manual showing the circuits?
If not you can download one for a 160/170 here (hopefully the same) http://www.mediafire.com/?ux89bq2u4u3ug
Look at the the circuit diagram for the start with and without the bypass switch on. It is either something in that circuit, most of which you have tested, or
Some key switches have two power on terminals on the back but only one stays energized during while the key is in the start/crank position. and pehaps that is where you get the current interuption from.
Let us know how you make out.
Ken

Thanks Ken. I fixed my settings, so hopefully my formatting works better.
I took a look at the manual per your link. It seems the wiring diagram section is missing though. Pages 55-16, 55-17, and 55-18 seem to be were it should be, but these pages are blank when I view it... It might be helpful to look at the circuit as you say to see if that brings anything to light. I don't believe this key switch has a second power terminal on it. I'll take a second look though.
Still digging,
Mark

 

[skidsteer.ca]

Thanks Ken. I fixed my settings, so hopefully my formatting works better.
I took a look at the manual per your link. It seems the wiring diagram section is missing though. Pages 55-16, 55-17, and 55-18 seem to be were it should be, but these pages are blank when I view it... It might be helpful to look at the circuit as you say to see if that brings anything to light. I don't believe this key switch has a second power terminal on it. I'll take a second look though.
Still digging,
Mark

See page 542 and 546. There is a diagram and some explanation of how the circuits work.
Not sure why those other pages are blank, I'll have to check the master copy
Ken

 

[markplow]

See page 542 and 546. There is a diagram and some explanation of how the circuits work.
Not sure why those other pages are blank, I'll have to check the master copy
Ken

I found that there is a rather general wiring diagram (would not call it a schematic) in the operator's manual. Between this and some probing I was able to figure out somewhat the how the service/run switch works. I was getting some weird resistance readings on a couple terminals (based on what I was guessing I should see), so I created a little jumper across the terminals to mimic what I thought the switch was supposed to do on these terminals. Yes, lots of guesses here.... If I turned the key to the start position and held it (engine didn't crank) and then jumpered these terminals it would immediately start. I was able to "turn the problem on and off" consistently in this way. So I made up a temporary jumper wire and installed it and so far that is working well. Ideally I'll try to get a new switch, but.... For now the only side effect seems to be that you can now start the machine without buckling the seat belt (kinda nice). I'm not 100% sure I didn't just bypass the problem, but it seems (if I understand the switch logic correctly) that it was indeed the switch. The ideal thing will be if I can get a new switch and remove my jumper.
For now it is working thought.
Thanks for the help.

 

[jerry]

I found that there is a rather general wiring diagram (would not call it a schematic) in the operator's manual. Between this and some probing I was able to figure out somewhat the how the service/run switch works. I was getting some weird resistance readings on a couple terminals (based on what I was guessing I should see), so I created a little jumper across the terminals to mimic what I thought the switch was supposed to do on these terminals. Yes, lots of guesses here.... If I turned the key to the start position and held it (engine didn't crank) and then jumpered these terminals it would immediately start. I was able to "turn the problem on and off" consistently in this way. So I made up a temporary jumper wire and installed it and so far that is working well. Ideally I'll try to get a new switch, but.... For now the only side effect seems to be that you can now start the machine without buckling the seat belt (kinda nice). I'm not 100% sure I didn't just bypass the problem, but it seems (if I understand the switch logic correctly) that it was indeed the switch. The ideal thing will be if I can get a new switch and remove my jumper.
For now it is working thought.
Thanks for the help.

Mark, that 665 thread is back on page 5 here. It was my machine and it turned out to be the starter interlock relay. Chip has a post in that thread on how to trace the power and that is what helped me. Otherwise the symptoms were the same as yours. To start with when you turn the key and you hear the little click don't quit, turn the key several times and it may kick in. Kind of like we used to do with a starter that had a weak soleniod. Interlock relay is in the engine bay fuse box just above the other two. I have some diagrams I got but the book does not have any that I could find.

 

[Chip S]

It could possibly be your s/r switch. If so, you can remove and disassemble it and clean the contacts. BTDT. The easier way to check it is to have an assistant sit in the driver's seat and buckle up. Put the switch on run. Pull the orange/white wire from the interlock relay and throw a voltmeter on it. Have the assistant turn the key. If you've got voltage, your switch is OK. Clean up all the connections on the relay real good, and make sure they fit the terminals tightly. I have copies of the wiring diagrams if you can tell me your specific questions.

 

[Chip S]

Just so there's no misunderstanding, the little relay box at the top of the relay center is not the interlock, that's for accessories, and will click when the key is turned on. The start interlock is a flattish relay box below it. It's about $45, so if you replaced it, you'll know it from the hit to the wallet. Ok, now that that's cleared up, on to the r/s switch. The white wire in the center is hot from the ignition switch, the w/dk blu goes to one side of the start relay, the lt bl/o ges to the fuel solenoid when the switch is in service. The Tan comes from the seat switch, the t/w goes to pin 4 on the eic. The w/lt green goes to the start interlock relay. With the switch in the service position, juice only flows to the fuel solenoid and the start relay, so you can start the motor but not use the hydro's. With the switch in the run position, juice must flow through the seat belt and two seat switches to engage the start interlock relay via the orange/white wire on the relay. If your getting juice there, that circuit is good. If it's the Interlock relay (chances are it is if you didn't replace it) and you can start the machine in the service mode, you can use the machine if you put the switch in service, start the machine, then scootch your butt up off the seat, put the switch in run, sit back down and buckle up. All the hydro's should work and you'll be good to go. All of the eic lights flashing as you describe sounds normal. If you need more specifics, let me know.

 

[markplow]

Just so there's no misunderstanding, the little relay box at the top of the relay center is not the interlock, that's for accessories, and will click when the key is turned on. The start interlock is a flattish relay box below it. It's about $45, so if you replaced it, you'll know it from the hit to the wallet. Ok, now that that's cleared up, on to the r/s switch. The white wire in the center is hot from the ignition switch, the w/dk blu goes to one side of the start relay, the lt bl/o ges to the fuel solenoid when the switch is in service. The Tan comes from the seat switch, the t/w goes to pin 4 on the eic. The w/lt green goes to the start interlock relay. With the switch in the service position, juice only flows to the fuel solenoid and the start relay, so you can start the motor but not use the hydro's. With the switch in the run position, juice must flow through the seat belt and two seat switches to engage the start interlock relay via the orange/white wire on the relay. If your getting juice there, that circuit is good. If it's the Interlock relay (chances are it is if you didn't replace it) and you can start the machine in the service mode, you can use the machine if you put the switch in service, start the machine, then scootch your butt up off the seat, put the switch in run, sit back down and buckle up. All the hydro's should work and you'll be good to go. All of the eic lights flashing as you describe sounds normal. If you need more specifics, let me know.

Thanks for the feedback. I am clear on which relay is the interlock relay. My dad replaced this so I don't know the details, but I know he replaced all three of the relays in the panel. And yes, the interlock one was not cheap, but he was able to dig it up on line somewhere for $9. He said he just Googled the company name on the relay (Potter and Brumfield) and found it. He doesn't have the details anymore of the exact site or anything. I just thought you might be interested in this for future reference.
I did see what each wire was doing on the switch, but I couldn't find anything about how the switch works (i.e. what connects to what in service vs. run mode). Nonetheless I made my best guesses in this area. Maybe I'll do the multi-meter test at the relay to confirm it. However, for now it is buttoned up and working well (numerous starts over a few days time), so this isn't my biggest priority right now.
Thanks.

 

[Chip S]

Thanks for the feedback. I am clear on which relay is the interlock relay. My dad replaced this so I don't know the details, but I know he replaced all three of the relays in the panel. And yes, the interlock one was not cheap, but he was able to dig it up on line somewhere for $9. He said he just Googled the company name on the relay (Potter and Brumfield) and found it. He doesn't have the details anymore of the exact site or anything. I just thought you might be interested in this for future reference.
I did see what each wire was doing on the switch, but I couldn't find anything about how the switch works (i.e. what connects to what in service vs. run mode). Nonetheless I made my best guesses in this area. Maybe I'll do the multi-meter test at the relay to confirm it. However, for now it is buttoned up and working well (numerous starts over a few days time), so this isn't my biggest priority right now.
Thanks.

The Porter and Brumfield part number is T92P7D22-12. I found one for $8.21 plus shipping.