Cat 320C SN# EAG00641 dead monitor

[Vetech63]

I had this thrown my way late today.

The customer had a lot of welding, boring, and bushing/pin replacement done on this excavator over the last month. The machine was delivered to them last Friday but the display monitor is dead. They called me to check it out........yeah, its dead, just nothing. 5-amp fuse and ground is good, same at the monitor plug. Replaced the monitor and it turns on but is a dead duck with a 588-9 communication error between the controller and the monitor. I have the schematic but it was getting too late in the day to do much. What I don't have is the legend for the ECM LED lights. I can see a green and yellow light but I can't see what they are or how they are orientated. Is there a legend and/or troubleshooting chart for these lights? I'd prefer to start there versus ohming wires until I get to that point.

Any insight would be appreciated as always!

 

[Nige]

First strange thing is that 588 Code (comms problem between controller and monitor) is listed as "321C, 315C, & 321C ONLY".

Attached the "Controller LED Function". Abbreviated controller/monitor schematic and troubleshooting flow chart below. Apologies for poor quality but it was the best I could get.

 

[Vetech63]

First strange thing is that 588 Code (comms problem between controller and monitor) is listed as "321C, 315C, & 321C ONLY".

This was confusing to me also. I ran across the same illustration online that was blank on any model specifics for that code. I'm not sure which is right but I'm giving yours the benefit of the doubt.

Apologies for poor quality but it was the best I could get.

Believe it or not, what you have supplied will help greatly! Thank You so much! I'll report findings when I have them.

 

[Vetech63]

Something strange happened today with this. I pulled up to the machine this morning, started it to let it warm up. Same barely lit monitor not doing anything, same yellow status light showing no communication. I'm parked right beside the cab going through my tech paperwork and I hear a beep in the cab......crawl up there and the dam monitor is on I hadn't even touched anything yet. So, I push the menu button and scroll to set the clock. I'm halfway through setting it and the LED screen flashes, goes blank, flashes again.......so I turn the ignition off, and the monitor won't shut down. I kill the master switch, turn it back on, key the ignition.....right back where it was when I first got there It did this same thing 3 different times for no apparent reason I can find.

Good ground, Good power, went through the troubleshooting chart......everything is pointing me to the controller. Checked and ohm'd the wiring. Haven't found anything I can positively point to. All it did was really frustrate the living hell out of me.

 

[Tags]

A gremlin electrical problem, doesn't get much more frustrating than that....you'll get her figured out though! Maybe you could get some help from the other "mechanics" that are "helping" with the equipment on your other thread.

 

[Kobelco ireland]

Maybe you could get some help from the other "mechanics" that are "helping" with the equipment on your other thread.

Feck you I just spat my tea all over myself laughing at that

 

[fastline]

Something strange happened today with this. I pulled up to the machine this morning, started it to let it warm up. Same barely lit monitor not doing anything, same yellow status light showing no communication. I'm parked right beside the cab going through my tech paperwork and I hear a beep in the cab......crawl up there and the dam monitor is on I hadn't even touched anything yet. So, I push the menu button and scroll to set the clock. I'm halfway through setting it and the LED screen flashes, goes blank, flashes again.......so I turn the ignition off, and the monitor won't shut down. I kill the master switch, turn it back on, key the ignition.....right back where it was when I first got there It did this same thing 3 different times for no apparent reason I can find.

Good ground, Good power, went through the troubleshooting chart......everything is pointing me to the controller. Checked and ohm'd the wiring. Haven't found anything I can positively point to. All it did was really frustrate the living hell out of me.

Just FYI, I just repaired one of these. Look extremely careful at the plug from the machine harness and monitor lead. Wires are anemic. If you see green corrosion of death, pursue that. Very hard to get to but if you can, it would be wise to back probe the power supply voltage on the monitor side of the plug and watch for Vdrop. The dim monitor would indicate poor contact to me. I found the entire connector to suck! Might need to 'adjust' some pins to strike better contact.

 

[Mobiltech]

Does your cab heater work? I have seen where the machine will start but the cab relay won’t come on so it runs but has no monitor , heater or radio. It will sometimes come and go too.

 

[Mbar]

I agree with the plug in. I had a b series test me. Good ground good power. You could get rowdy with the plug twisting and prying and it would light up. New harness and fixed.

 

[southernman13]

Had a 320C PAB s/n that had corrosion on the wires on machine side of the plug. Fixed the wire and she lit up. I think nige supplied the wiring info. Been a while. Good luck

 

[Vetech63]

Todays update.

I haven't been able to find anything definitive yet. This dam thing is so inconsistent it makes it difficult to troubleshoot. Since I couldn't point to anything with absolute certainty, I decided to call Cat out with their ET. I wasn't able to stay on that job as 5000 other things are breaking too. I filled in the tech on the latest history (all the welding) What I had done as far as troubleshooting and those results. He called me about an hour ago finding the same difficulties I'm having. He told me when he first got there the monitor came on......for about 45 seconds, lined out the LED and basically quit working. He hooked up ET and at first it saw the monitor.............and now it doesn't. He is coming back in the morning; he is having to contact tech support for assistance. I will go back by there tomorrow afternoon and assist if I can.

At least I am not the only one confused by this

 

[Vetech63]

Could be a wiring issue for sure. Everything I can test is showing good .........and all its doing is pissing me off LOL

 

[fastline]

Could be a wiring issue for sure. Everything I can test is showing good .........and all its doing is pissing me off LOL

I will put it to you this way. The one I fixed spent weeks at the dealer and they cost the previous owner thousands, then told him the machine needs a wire harness. After I found the issue, even a harness would not have fixed it! Don't let CAT run this up the rope of extremes. This sounds like a flaky contact. You know how to employ the wiggle test.

 

[Vetech63]

I want to see if 1 of you guys can check in SIS and verify the monitor part number. The original monitor and the replacement I bought have no tag or ID I can find. The Cat parts department, by machine serial number, gave me a part # 260-2160. The electrical schematic is giving a part number of # 157-3198. The number may supersede but I want to make sure I have the right one just to satisfy my thoughts.

I will put it to you this way. The one I fixed spent weeks at the dealer and they cost the previous owner thousands, then told him the machine needs a wire harness. After I found the issue, even a harness would not have fixed it! Don't let CAT run this up the rope of extremes. This sounds like a flaky contact. You know how to employ the wiggle test.

I did run new wiring outside of the machine harness with no effect. Something isn't making sense here.

 

[Nige]

The Cat parts department, by machine serial number, gave me a part # 260-2160. The electrical schematic is giving a part number of # 157-3198.

Often Part Numbers don't get updated on schematics, even when the schematic itself gets updated, because it simply slips through the net.
Seems like that has happened here because 157-3198 updates to 260-2160.

 

[fastline]

I want to see if 1 of you guys can check in SIS and verify the monitor part number. The original monitor and the replacement I bought have no tag or ID I can find. The Cat parts department, by machine serial number, gave me a part # 260-2160. The electrical schematic is giving a part number of # 157-3198. The number may supersede but I want to make sure I have the right one just to satisfy my thoughts.

I did run new wiring outside of the machine harness with no effect. Something isn't making sense here.

I obviously don't have the complete rundown but if you are getting a dim or sporadic backlight, that would be something to address first. What is the battery voltage and what is voltage at monitor when running. It might be a good measure to check amperage on the power wires first.

Basically the data link will be sending a pulse train of digital data. The chipset in the monitor will need power for RX/TX. Gotta have good stable power first. No way anything on that board runs at 24V though. Usually 5V or 3.3V

IIRC, there is a 12V converter in the cab for the radio but I can't recall if that power goes to the monitor. I think it does. It might be worth pulling the fuse on the radio as interference can most certainly jack with a data link, but rarely on digital, and that does not explain the power issue.

 

[Nige]

See the abbreviated electrical schematic in Post #2 above. The monitor is supplied with Batt+ (24v) via wire 103-RD.
What happens inside it to run the internal components is another matter.

 

[Vetech63]

I appreciate the assistance fellas. The Cat tech has checked out everything that I did and came to almost the same conclusions. He is leaning toward the new monitor (could be, it crossed my mind) I have is faulty. He brought another in for this morning to try. I'll update tonight.

 

[southernman13]

I forgot on mine I did like you and wired it up outside the machine from an external power source to determine it was good. Nige had provided a wiring diagram for me. I remember there wasn’t much room to fix the plug from the machine wiring harness. Anyway I hope you are able to get it going. Aggravating as hell trying to figure **** out sometimes.

 

[Vetech63]

The Cat tech called me yesterday morning......the part didn't show up. He will be back Monday. Its par for the course .......this entire week has been nothing but a problem child, it's fitting it ended that way.