D5K YYY00538 Can someone help me with the 30amp side of this Vdc fuse relay? Part # 275-0490 Trying to avoid cutting open wiring harness to trace it. This tractor has a patristic draw of about .70amps and drops to .03 when I disconnect this circuit. Thanks
The attached might help. Check your messages for an electrical schematic.
I replaced the Vdc fuse relay because it had a hot spot on it. It was still working properly and tested fine. I am still having some electrical problems that are over my pay grade. I'm not sure Im testing this the correct way. Issue: Parasitic draw with key OFF, drains batteries overnight (0.7 A) Measurement Setup Master battery disconnect OFF Battery negative disconnected Multimeter in series on ground side (negative path only) Test light clipped to machine ground, probing battery negative → light illuminates briefly Initial Isolation All battery positives removed from: Starter Alternator Fuse panel With positives disconnected → no draw Touching any positive cable back → draw returns Fuse / Relay Testing All fuses pulled → draw remains All relays unplugged → draw remains 1- 15A fuse (pink wire) kills draw, only when instrument panel is disconnected. Pulling fuse with full machine assembled → no effect ECM Testing Engine ECM unplugged → no effect Cab ECM (behind battery) With most of the machine disconnected: Unplugging J2 → draw drops to ~0.03 A With machine fully assembled: Unplugging J2 → draw remains
Go and disconnect the Alternator wires and wrap each wire end with tape and see if draw disappears. Have seen where a burn't control diode inside it is I believe what it was, was drawing down the battery over night. Simon C
I have the alternator completely unhooked.
I have not seen the schematic for that unit, but if the master disconnect is off it is impossible for your batteries to discharge unless if your master disconnect switch is still on inside while switch is off outside. Unless if you have something else tied to battery negative that I am not aware of. Picture of your batteries would help. Try disconnecting the jumper in between your 2 batteries and see if load drops out. Have seen one battery discharging another one before. Simon C
I don't have the schematic, but on my 328Dlcr machines, I had to disable the product link on all 3 of them.
Product link if it has, as I have not seen schematic can draw substantially, depends on how it is wired back to batteries. Simon C
Have also seen Control modules that are still awake all night , but it was on a system without disconnect Switch. Simon C
Okay so looked at your schematic and your disconnect switch is faulty, or you have something else tied into battery other than what is on schematic, or you have one battery sucking down the other on your 12 volt parallel system battery set up. Simon C
It won't be the first time that the contacts of a master disconnect switch have welded themselves together.
I have manually disconnected the master and placed my voltmeter between the frame ground and the battery. I have also checked the master switch itself, and it properly disengages continuity. Both of my batteries have also been replaced. I have removed the jumper cable connecting the two batteries. The engine-side draw ceases when I remove the jumper, but the short or draw persists on the cab side of the machine. I dont know anything about product link, or if my machine even has that.
I've seen batteries bleed 12 volts thru the case Try positive terminal to frame with negative cable off
It has Accugrade, so it also should have Product Link. Whether or not the subscription for it is activated or not makes no difference, the modules will still be powered. See the schematic I sent you, Page 12, Grids G-3 and H-3.
This is the second set of batteries and the same problem. I have voltage on the negative side of my batteries. 0.7ma and 11volts. If I use a test light that's grounded to the frame, and touch the negative post the light will flash very dimly. I think I have something shorted internally .
So seen your pictures and you have an above and a below battery. If neither battery has nothing like a small wire hooked up to the negative post, just want you to know that I noticed that they look like an aftermarket battery. They may be having a hard time to charge up and if one does not charge to full, being they are parallel connected, the lower charged one will bleed off the higher charged one. Also you have the lead style connectors which have fooled too many guys not knowing that they burn off internally slowly causing undercharging of one battery or both. Your bottom side battery looks to have a little maybe corrosion on the positive terminal going up under the red skin cover. Maybe I am seeing wrong. I would load test both of those batteries cables while flowing a lot of current to rule out internal burnt off. I always drill a tiny hole in the top of the battery post to thread in a small wood screw to hook up my meter aligator clip to the battery post while hooking up my big alligator clip on my other lead to either the other end of the same cable at Starter solenoid, or if your testing the black ground cables test all the way back to the Battery side of the Master Disconnect switch. I would not be surprised if one cable is faulty inside causing poor charging and subsequent discharging. Also seen that your Alternator Positive cable is tied into both batteries through the Starter Solenoid Positive post up to the Bottom Battery positive post. It then feeds the top battery Positive post. One bad connection and your problem will never end. Dont buy anything else without testing these. If your not exactly sure how its done I can explain. Hope you get it figured out. Simon C
Re- reading everything you have done I do not believe your master disconnect switch is working correctly. How exactly did you test it as a test light will only work if enough power and current is flowing, but if too low of voltage and current will not give you a voltage drop reading. The pictures you posted show 4 genuine cables attached to batteries and nothing else unless something is hooked up underneath that I cannot see. If nothing else is attached out of picture view your master switch is in need of voltage drop test with it all hooked up. You could very well have a few small problems adding up to battery discharge. Simon C
I tested the master disconnect switch using a volt‑ohm meter and checked it for continuity. I can confirm there is nothing else hooked to these batteries. Tomorrow I will bypass the factory battery cables with a set of heavy jumper cables to rule them out. I really don’t think they are the issue. I inspected them closely before installing the new batteries. I will also bypass the disconnect switch to rule it out as well. Thank you for all the help.
You cannot test a master disconnect switch with an ohm meter as a cable with 100 strands and 99 of them broken will test 100% good with an ohm meter, but nothing will work. Your switch needs to be tested with all the cables on battery hooked up and cable from battery to master disconnect, disconnected at switch.. Then put your meter in between the one post of master disconnect that has the cable removed , with other meter lead on the disconnected cable sitting on a rag. Your meter has to be on DCamps 10 amp scale. If anything flows through your meter your master switch is junk. Simon C
That is how I have been monitoring the draw on the system. I have my meter in line between master disconnect switch lug and battery ground. When I checked the switch for continuity I was just confirming the master switch closed or turned off all the way.
Sorry, but if you had the master switch turned off and the small 0.7 amps or whatever was still going through your meter. That means the master switch is junk. An OHM meter test only tells you , that you are on both ends of a wire, tells you nothing about the integrity of the cable. I know we are talking about a master switch, but it can only be tested under load or with your meter in between as you say you done. There is no other small wires hooked up at batteries so it means the leakage is through the master switch. That being said you may have a module or something else causing the draw, but the master switch is suppose to stop it. Fix one thing at a time. Simon C
I finally had some more time to troubleshoot this machine, and I wanted to update where I’m at. I may not have explained the master switch correctly before, but I can now completely eliminate it as a suspect. Even with the master switch totally removed from the circuit — meter between battery negative and machine ground — I still have the draw. I’ve tested the switch separately and it’s functioning properly. At this point, I’ve disconnected every single connection in and under the cab. There is nothing left hooked up in the cab at all. The only thing still connected is the J2 plug on the computer behind the battery . When I disconnect that J2 connector, my voltage drops to zero and the draw disappears. The same thing happens if I pull the original 15‑amp fuse I started with — as soon as that fuse is out, the draw drops to zero. So now I’m wondering if there’s a way to test the computer itself. Is there a method to ohm‑check or otherwise verify whether I’ve got an internal fault inside the ECM?
Have you timed (stopwatched) the draw? The ECM doesn't go to sleep right away, either after shutdown, or at battery turn on (at the master). Rule of thumb has always been 10 minutes.
Yes, I can let the machine set for an hour and nothing changes.
What I explained in post #21 does not stop your parasitic draw that is happening within the wiring system, all that post is saying is that your draw that was and still is happening is going through the old master switch, which even if it was say 5 amps , the master switch is suppose to stop it. Your master switch was not stopping it. The problem causing the draw is what you are after now. That 275-0490 Relay fuse assembly feeds your grid heater direct from 310-EN19PU8 cable . If relay contacts are stuck on at all it can go to the heater. Try disconnecting grid heater and see if draw disappears. If it does maybe we need to look more at that relay. Simon C
I’ve got that relay completely disconnected from the machine right now. Everything is still unplugged, including all the harnesses. Nige mentioned the possibility of AccuGrade or Product Link being involved, if this machine has it, I haven’t been able to locate the components. Does the picture I posted show the correct locations for those modules if the machine is equipped with them?
Yes it does.
If the relay is completely disconnected, then that rules it out totally if the draw is still there. Will look again as we are not there and can only get you to look for us. Simon C
Just had a look at the schematic and between the Accugrade and Product Link there is a lot of possibilities for battery draw. Maybe Nige can comment but I would stop the draw from completing the circuit back to battery negative and run the machine as is or you will need some just out of Cat Technical training hands to help. There is a lot to consider before getting all this extra figured out. Simon C
Are you referring to #8 in the illsutration below.? (The Black ECM.) If it is then I would like to suggest getting hold of some Deutsch connector de-pinning tools and de-pinning some of the wires in connector J2, but leaving it powered, in an attempt to determine which wire(s) exactly are causing the parasitic drain. Most of the wires connected to J2 (apart from power) fall into 2 categories. Control/feedback circuits and the CAN A/CAN B datalink wiring.
Yes, that is the J2 connector I’m disconnecting — removing it stops the current draw. Also, is it possible for this machine not to have a product link? I don’t see anything like that on the inner fender or under the floor panel. Thank you for your patience, I’m learning as I go.
Definitely possible. The system "implies" that your particular Serial Number has Product Link but NOWHERE does it come out and clearly say that.
Have not heard anything in 10 days, not sure if you figured it out. Simon C