Fuel primer pump has 24 volts to pigtail once I plug it in it drops to 2 volts and will not turn on at different occasions it has turned on but when I turn the key on I haven’t been able to get it to turn on I can hook 24 volts directly from the battery and the pump turns on I’m not sure what could be causing this issue
Post a machine Serial Number. The electrical schematic should indicate where the pump gets its power from.
The serial number is cat00d6nvsgg00397
Thanks for that. Can you post a photo of the pump please. Is it part of the primary fuel filter/water separator assembly.? Also can you confirm the colours of the two wires that are on the machine side of the 2-pin connector feeding the pump (not the pump pigtails). From what I see they ought to be marked 323 White and A278 Black.
It is not part of the primary fuel water separator it bolts on at the back of the dozer just under the fuel tank And the two wires are white and black new pump is the one on the right
OK I see it now. I'll send you a copy of the electrical schematic for the machine. The power supply for that pump comes from the engine ECM. I can see at least one connector that it goes through between the pump and the ECM but my first suspicion is that a wiring harness has rubbed somewhere and is shorting out the power supply.
So I wanted to thank you the information you gave me and once talking to the dealership and looking back on those same problems we came to the conclusion that the new pump was drawing to much that the ecm couldn’t handle it we found that some of these dozers came with a relay and some didn’t so we ended up up putting a relay in using the ecm signal to power the relay and bringing power in to the relay from a auxiliary power port on the harness with its own dedicated fuse and it seems to be working now thank you again
If it was an aftermarket pump that is certainly a possibility.