Hello all I’m having an issue with my skid that I can’t seem to figure out. Here’s what happened: The communications group module in the cab that provides gps etc is double sided taped behind the seat. My machine was giving me weird codes so I went to remove the module and a wire broke which caused a white flash from the wires (short circuit), the machine was running and died, then I checked the fuse panel- all fuses are grounded out, I found one inline 15amp under the cab that was fried/ I replaced it now the ignition switch relay clicks but nothing else. The mega fuses are good with 12.4 V on each leg, the starter exciter wire has no power with KOEO, under the cab their are three large power relays tha each hold two fuses, the first fuse has an orange and a red wire I believe and the orange wire has no power into the relay, all the fuses under the cab are good except for the one I mentioned that I replaced. I’m stating to think my ecm is fried but none of the fuses to it have been an issue, I can’t get into sis for some reason and really need help it’s stuck in my driveway. Does anyone have a wiring schematic for Vin#DZT3686 I do have power in the main battery cable to under the cab the largest red cable has 12.4, same to the mega fuses 12.4v, entire fuse panel shows all fuses are grounded. TIA
That doesn’t sound like anything factory…… Check your message jnbox.
Hello thanks for the reply, Yes that’s why I wanted to remove it but it is a cat part #550-3269 , I didn’t like it on there beeping and that goes with it and found it was unnecessary. Just wish my dumbass hadn’t done it while running.
Thank you I’ll check my inbox / much appreciated
That’s for the Product Link system. It may be shown as an attachment on the electrical schematic but if not attached are the instructions for installation that you may be able to reverse engineer to remove the system. I’m pretty sure you will find it requires ET to reconfigure the Machine ECM so that it is not permanently looking for the PL box which will throw other Codes.
Thank you for your reply, I had read it could be taken off/ but I didn’t read the part about reconfiguring the ecm. I am at my maximum level of smartness on this/ starting to think it’s going to be dealer bound but am trying to avoid that. I can’t get it to power up at all / no screen, no beeps no lights, I’m about to go swap the starter relay with the glow plug relay and see if anything changes but it probably won’t. I’m worried this might be worst case need new ecm and that product link module. I’m still searching the wiring schematic but it’s been years since I worked for Cat , I don’t have the laptop anymore for this machine. I hate to throw in the towel as a tech myself but man… thanks for the info/ atleast now I know if it starts it’s not going to be back to normal without that product link box.
I know my issue lies somewhere upstream of the mega fuses and I have no constant power to the ignition switch but the relay clicks, power probe forcing power to ignition switch makes screen come on for a split second then goes back out
Every fuse in cab shows ground in both sides, 100amp relay under cab has no power coming in on orange wire / still searching schematic for this one to trace it
hot side of 100amp relay module under cab does have 12.4
You have 2 Power Module Relays under the back side of your cab along with 1 Power Relay ECM there also. They have a 20 amp fuse and 60 Amp slow blow fuse there from the schematic that I have. Are any of the fusings there blown or needing re-set such as the slow blow 60 amp. Are those relays receiving signal power to get them latched. Module #1 Relay has control signal wire 308-C177YL-18 Module 2 Relay has control signal wire 308-C178YL-18 Power Relay ECM has a 20 Amp Slow blow Breaker and a 30 amp Fast Fuse The control wire is 128-C107Rd-18 Need to check these ,as these relays feed 2 fuse panels and lots of stuff. If the power is not at these control wires we will have to trace back to see where the signal source comes from and through how many connectors. Simon C
Just want to say there is a buss bar that feeds these 3 relays , seen on the top of them on the schematic. The power that feeds these comes from a big 100 amp fuse that is on left wall of engine compartment with a large red wire # 101-RL-46RD-4 that passes through Connector2 that goes to the 3 relay tops. Not sure if you had power on all these. Simon C
That 12 Gauge orange wire is output from the Power Relay ECM. It is switched power coming from the 20 amp slow blow fuse on the top of that relay. The signal wire for that relay is as posted in above #10 a 128-C107RD-18 ( Red wire ). Let me know if you have tested the signal wires. Simon C
Hi Simon and thank you very much for reading my post and sending a reply. I know of the slow blow breakers and fuses under the cab you mentioned, none of them are blown or broken etc , the 100amp mega fuse is also not blown nor is the 50amp next to it on the left side wall of engine bay - they are all in tact, I did find one inline 15amp fuse in front of the slow blow breakers under the cab/ it was just a fuse dangling from a red wire that is hot and I replaced the fuse and it didn’t blow again. Now I do have power on 101-RL-46RD-4 but not on wire 304 I believe and 307 both orange wires that make the machine start I presume, I am stuck at the starter right now I have no power on signal wire and no power coming out of solenoid on KOEO I am going to ohm the starter solenoid out and if it fails the test or is open etc I’m going to order a starter/ I just don’t see how a dead starter would cause no response from the key or screen but that’s where I’m at and what my research tells me could be the case, I just almost don’t believe it’s the starter but I did cause a dead short so I guess it shorted somewhere which is how this started / I have no power to ignition switch and no power coming out of ignition switch. I also tested the j1939 Can wires and they ohm at 60ohns so I think my ecm is still good. I’m probably going to get a starter and see what happens but want to ohm it out first and didn’t have time today, I’ll update what the findings are with that, but yes I’m still stuck and none of the fuses mentioned have any breaks or issues and they test at 0 ohms. Do you think I need to visually inspect every fuse in my fuse box in the cab -Every fuse in cab grounds out on both sides of the fuse / when I turn the key I hear a slight click from a relay in the fuse box in the cab/ didn’t investigate that further because the key gets its juice from the starter- don’t understand that but that’s what I’m reading so yea that’s where I’m at. Thanks for reading / I appreciate all you guys that take the time to help , I’ve been a tech a long time and sometimes stuff just throws me a curveball. Electrical is my least strongest trait in the trade but I think I’ll know more in the next day.
I will test the signal wires tomorrow and give you a definitive answer sir thank you again
After reading your response I’ll make sure and check this stuff out more before I waste time on the starter which I believe is a result of the signal wires not sending signal. Talk soon and thanks again
Don't buy a starter with out jumping the starter for 2 seconds with power from the Starter solenoid large Red cable to the solenoid " S " terminal to see if it cranks. ( " S " terminal should be a White 12 gauge wire attached to it. ) If it cranks at all the problem is in control circuit elsewhere. There is a small fuse next to the 3 relays under the cab that feed the KEY Battery power. Check that area out very well as there are other fuses there also. Don't be firing the parts cannon till everything has been tested. Simon C
Hey gents I got it fixed it was an inline 15amp fuse under the cab and a hard reset and she runs with no codes. Thanks for all the help for sure! Cheers!
As I said , don't start the parts cannon without checking under cab, all fuses. Glad you found it. Simon C
Hey thanks Simon , actually it was the 15amp fuse I had mentioned to you previously / I just hadn’t turned off the master switch - apparently whatever it did when I turned to master off and then back on today it’s reset the whole thing, but thank you for the direction, I was going to check what you said and then it just started up like normal. The gps unit and everything is off of it and no new codes.