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Help me solve this tech issue on this Cat
- Thread starter Vetech63
- Start date
The wiring plug is there for the sensor, but it is factory capped.
The wire numbers are correct at this plug per the schematic. So my question is...............how and where is this machine getting a position sensor signal to Machine ECM pin #18 without it? Do I have the wrong schematic? Cat tech service is stumped at the moment and isn't any help. The operation of this FNR is by a cable straight to the pump lever control. The 2-wire neutral start switch is there at the lever also. So, what gives? I am trying to keep from breaking into the wire loom all over the machine trying to find what's going on.
The wire numbers are correct at this plug per the schematic. So my question is...............how and where is this machine getting a position sensor signal to Machine ECM pin #18 without it? Do I have the wrong schematic? Cat tech service is stumped at the moment and isn't any help. The operation of this FNR is by a cable straight to the pump lever control. The 2-wire neutral start switch is there at the lever also. So, what gives? I am trying to keep from breaking into the wire loom all over the machine trying to find what's going on.
BigWrench55
Senior Member
Could that be a terminated resistor or a diode in that plug ?
I was hoping it was a sis login but nooooo.
heymccall
Senior Member
I think you need UENR7076-04 for the schematic?
Not sure my friend. Thats a thought though!
I'm not even that lucky LOL
HMMM......I will have my product support guy check into that this morning. The wrong schematic makes more sense at this point.
Well, here is what happened. The schematic I have is the correct one according to Cat. I visited with Cat tech support this morning which was no help at all. I was trying to get an explanation of how this system on the FNR/Vibratory worked and he kept talking over me. After about 2 minutes of this, I had decided I was going to get nowhere with this guy. All he could suggest was to hook up ET to it and modify parameters on the Machine ECM. I already knew this wasn't an ECM problem, so I was on my own.
What I did figure out is the vibratory operates through the Machine ECM, and that signal the ECM needs to turn them on comes from the neutral start switch. Once you have the machine engine started, if you select vibrators from the command button on the joystick, it sends the "ON" signal to the ECM. Once you move the FNR lever forward or reverse off the neutral detent, the neutral start switch opens which closes a switch in the ECM that tells it the machine is moving........in turn the ECM turns on the selected vibrator solenoids.
The fix was replacing a weak springed neutral start switch and an exact adjustment of its height on the pump control housing. It took all of 10 minutes to repair.
I'm still aggravated about the tech support guy. He is one that I have dealt with for years, yet he didn't seem to give a rat's ass about helping to explain how the system worked so I could troubleshoot it properly (especially considering the schematic is showing components in the system that just aren't there). I'm beginning to wonder if he even knew how it worked.
What I did figure out is the vibratory operates through the Machine ECM, and that signal the ECM needs to turn them on comes from the neutral start switch. Once you have the machine engine started, if you select vibrators from the command button on the joystick, it sends the "ON" signal to the ECM. Once you move the FNR lever forward or reverse off the neutral detent, the neutral start switch opens which closes a switch in the ECM that tells it the machine is moving........in turn the ECM turns on the selected vibrator solenoids.
The fix was replacing a weak springed neutral start switch and an exact adjustment of its height on the pump control housing. It took all of 10 minutes to repair.
I'm still aggravated about the tech support guy. He is one that I have dealt with for years, yet he didn't seem to give a rat's ass about helping to explain how the system worked so I could troubleshoot it properly (especially considering the schematic is showing components in the system that just aren't there). I'm beginning to wonder if he even knew how it worked.
Birken Vogt
Charter Member
I just got that yellow spiral bound book on electronics for my apprentice. I was browsing through it yesterday. Lots of pearls of wisdom in there. One of them is
Mechanical problems = fast to diagnose, slow to fix
Electrical problems = slow to diagnose, fast to fix
I am going to remember that one.
Mechanical problems = fast to diagnose, slow to fix
Electrical problems = slow to diagnose, fast to fix
I am going to remember that one.
Nige
Senior Member
I think I see just a hint of one of the white plastic plugs that are put into the open ends of unused connectors in his 2nd photo.
Allegeldy not for his Serial Number. UENR7067 only applies to Serial Numbers 146-Up. He has 134. Even then UENR7067 still shows the same sensor as being standard, not an attachment. See below.
The FNR position sensor P/N 266-1470 is only listed as being part of an Attachment for 448-0063 or 367-6597 Propel Lines Group applicable for machines equipped with Traction Control. Machine 42500134 is not so equipped. The Propel Lines Gp for it is a 367-6611, part of 456-2576 Hydraulic Arrgt. If normal convention was followed the position sensor really should be located inside as dashed boundary on the schematic marked "Traction Control (ATCH)" - IMHO.
For anyone who had never come across one of these machines before the SysOp section of the Service Manual regarding the propel system basically isn't worth the paper it's written on as regards helping to explain how the system operates. The info about the neutral start switch is actually hidden away in the Propel Pump SysOp. WTF..??
This may interest you...........procedure to adjust the neutral start switch
- Depress the parking brake knob in order to engage the parking brake.
- Move the propel lever to the FORWARD position. Hold the engine start switch in the START position. Slowly move the propel lever toward the NEUTRAL position.
- If the engine starts before you move the propel lever to the NEUTRAL position, the neutral start switch requires adjustment. Do not operate the machine until the repairs have been made. Refer to the service manual for your machine for the procedure on neutral start switch adjustment.
- Move the propel lever to the REVERSE position. Hold the engine start switch in the START position. Slowly move the propel lever toward the NEUTRAL position.
- If the engine starts before you move the propel lever to the NEUTRAL position, the neutral start switch requires adjustment. Do not operate the machine until the repairs have been made. Refer to the service manual for your machine for the procedure on neutral start switch adjustment.
heymccall
Senior Member
So, if I'm following correctly, the failure was a faulty neutral switch?
Nige
Senior Member
That's the impression I got.
Yep. Makes no sense if you read the schematic
Nige
Senior Member
Correct! But what’s the fun in it being like it’s supposed to be!?
Nige
Senior Member
Just for sh1ts & giggles I’m going to flag it on SIS feedback and see what response I get.