We have 2 T770's and one is a 2019 that has a current draw and doesn't want to turn over after sitting for a few days. It has a new Interstate battery and the alternator charges well..... when sitting for 4 days the battery voltage is down to around 11.0 before turning the machine over. When disconnecting the battery ground cable with the ignition switch off, my amp meter shows a current surge to about .18 amps for a couple seconds and then varies between .07 - .10 amps constantly between the neg battery cable end and the ground terminal on the battery. .07-.10 amps is a lot of power to be constantly drawing with the machine shut off. There is no 2 way radio in the machine or anything else that could be left on that I can find. I disconnected the wires off the back of the alternator to see if there may be an issue in there and it didn't make any difference in the current draw. We checked the other newer T770 we have and it draws .10 amps for about 2 seconds and then settles at about .003 amp draw..... much less. Has anyone run into a similar power draw on one of these Bobcats before ?
pull the fuses for each individual controller. Checking each time what you have for a draw. If there is a controller not going to "sleep" then you might have a problem in them. Generally after the key is cycled off the controllers will stay awake for a little bit and then shut off. "We checked the other newer T770 we have and it draws .10 amps for about 2 seconds and then settles at about .003 amp draw..... much less." <<<< thats the controller shutting down. Give it a try. Ive played hell with these bobcats ever since we became a dealer and pulling the fuses is the best way i can think of to quickly isolate the problem. Let me know what you find.
I pulled all the fuses one at a time and the last one I pulled was the F11 GWY fuse (25 amp) and it makes all the current draw stop.
Thats the fuse for the Gateway controller. Do you have any codes that show up? When you plug the fuse back in does the amp draw come back or does it seem better?
When the F11 fuse is plugged back in the power draw continues. There is no active codes currently but there are a lot of stored codes..... which some may be from the operators trying to start it with a low battery. It hasn't done any work since we replaced the battery on this past Friday. The machine has 1456.4 hours on it, and the last codes were M0309 at 1455 and 1454 hours.
I believe the 770 is a DEF system. My DEF machines (CASE) purge the DEF out of the lines after the machine is shut off and after that completes it really shuts down. Does your BC do something similar? Is the DEF purge system still drawing after its purged the system?
Yes it has a DEF system and it usually purges after the machine is shut off, but I have had my ammeter on for over half an hour after the machine is shut off and we still have this power draw. The battery loses voltage after it sits overnight and even worse after a few days. Our other newer T770 Bobcat does not have this problem or power draw.
Here is the stored codes…… as I mentioned none of them are active now and I think many were triggered by trying to start it with the battery very low.
2nd pic…..
3rd pic……
M0309 is a pain but it definently can help in weeding out some fault codes that arise. can you disconnect the plug from the gateway, should be the one under the cab on the lh side, and see if there is a wire rubbed through or maybe some corrosion on the connector or the plugin on the gateway? generally it should throw a code for a short or saying that a function is commanded without operator input. If it were me and all that checked out id be slinging a new gateway at it if everything else checked out. a guy can always make sure you have good connections yada yada yada.... J1 CONNECTOR ASSIGNMENTS(GATEWAY CONTROLLER) PIN FUNCTION PIN FUNCTION A-1 HYDRAULIC LOCK RETURN B-1 HYD CHARGE PRESS A-2 LIFT SPOOL LOCK RETURN B-2 UNSW BATT A-3 FUEL PULL RELAY B-3 UNSW BATT A-4 SWITCHED POWER OUT RELAY B-4 FUEL HOLD A-5 LIGHT 1 RELAY B-5 LIFT SPOOL LOCK A-6 GLOW PLUG RELAY B-6 TRACTION LOCK HOLD A-7 STARTER RELAY B-7 TILT SPOOL LOCK A-8 TRACTION PULL RELAY B-8 CAN LO 1 A-9 B-9 CAN HI 1 A-10 TILT SPOOL LOCK RETURN B-10 A-11 AC SENSE B-11 SEAT BAR A-12 SPARE DIGITAL, ECU SOURCES B-12 FUEL LEVEL A-13 TRACTION PULL RELAY FDBK B-13 BICS HYD LOCK HOLD A-14 GLOW PLUG RELAY FDBK B-14 CAN HI 2 A-15 ENGINE SPEED B-15 GROUND P1 A-16 AIR FILTER SWITCH B-16 GROUND P2 A-17 REAR LIGHT 2 RELAY B-17 GROUND P3, SENSOR A-18 FAN 2 RETURN B-18 A-19 PTOL LED B-19 FAN 2 OUTPUT A-20 PTOL SWITCH B-20 CAN LO 2 A-21 SWITCHED POWER OUT RELAY FDBK B-21 REMOTE RUN KEY A-22 STATER RELAY FDBK B-22 RUN/ENTER A-23 B-23 SENSOR SUPPLY 8V A-24 START ENGINE B-24 SENSOR SUPPLY 5V A-25 WATER IN FUEL B-25 TWO SPEED MAKEUP A-26 TWO SPEED RETURN B-26 TWO SPEED COIL A-27 TWO SPEED MAKE-UP RETURN A-28 REAR LIGHT 2 RELAY FDBK A-29 A-30 FUEL PULL RELAY FDBK A-31 FRONT WORK LIGHT 1 RELAY FDBK A-32 HYD OIL TEMP (8 VOLT) A-33 A-34 HYD OIL FILTER SW1
J2 CONNECTOR ASSIGNMENTS(AUXILLIARY CONTROLLER) PIN FUNCTION PIN FUNCTION A-1 FRONT AUX (F) RETURN B-1 A-2 REAR AUX (F) RETURN B-2 UNSW BATT A-3 LEFT BLINKER RELAY B-3 UNSW BATT A-4 RIGHT BLINKER RELAY B-4 DIVERTED SOLENOID A-5 HORN RELAY B-5 REAR AUX (F) A-6 B-6 RELIEF SOLENOID A-7 B-7 REAR AUX (M) A-8 B-8 CAN LO 1 A-9 B-9 CAN HI 1 A-10 REAR AUX (M) RETURN B-10 A-11 B-11 A-12 B-12 A-13 B-13 FRONT AUX (F) A-14 B-14 A-15 B-15 GROUND A-16 B-16 GROUND A-17 B-17 A-18 FRONT AUX (M) RETURN B-18 A-19 B-19 FRONT AUX (M) A-20 B-20 A-21 B-21 A-22 B-22 SWITCHED POWER A-23 B-23 A-24 B-24 A-25 B-25 HYDRAULIC BOOST A-26 HIGH FLOW RETURN B-26 HIGH FLOW A-27 HYDRAULIC BOOST RETURN A-28 A-29 A-30 A-31 A-32 A-33 A-34
^^ should be the pin out for both the gateway controller connectors. Look at the switched power and unswitched power. See what all you have going on there. Coud maybe look at the switched pwower relay aswell. hope this helps some.
yes that steers me in the right direction....... thank you.
Do you have power distribution diagram. Is it possible that there are other circuits receiving power from the fuse that feeds gateway.
I will disconnect the Gateway module tomorrow and see if the power draw stops….. if not we will go thru the wiring from the gateway module to the fuse and a wiring diagram would be helpful.
Disconnected both plugs from the gateway module and the power draw is still there…… will go thru the wiring and try to see if there is any thing else on the circuit.
Where you ever able to get your problem sorted out?
I know... it would be nice to hear back, if they were successful.
Satisfy my curious side. Cheap check that costs nothing but your time. If you have a 12 volt test light, disconnect the large output lead from the alternator. Connect your test light between that terminal and the wire you removed from it. with the machine NOT running, the test light should stay totally dark. If the test light is on, that tells me you have one or more bad diodes in the alternator. The alternator can show a decent charge rate with a bad diode BUT allow a battery to discharge over time. A diode is like a check valve for electricity. Only allows flow in one direction.
He already did that, in his first post.
no he didn't. He checked amp draw passing through the ground
4th paragraph, first post, disconnected wires on back of alternator. Regardless, he is not responding as to what he found. But you made a good point.
Satisfy my curious side. Cheap check that costs nothing but your time. If you have a 12 volt test light, disconnect the large output lead from the alternator. Connect your test light between that terminal and the wire you removed from it. with the machine NOT running, the test light should stay totally dark. If the test light is on, that tells me you have one or more bad diodes in the alternator. The alternator can show a decent charge rate with a bad diode BUT allow a battery to discharge over time. A diode is like a check valve for electricity. Only allows flow in one direction. stefuel , Feb 12, 2023 Report Have to agree with your possible diagnosis. One burnt diode will still charge at 33% is what I was taught. Have seen one alternator that was doing exactly as you have said. Simple test with no money involved. That is part of the KISS Theory that I was taught years ago before spending big dollars and problem still there. Hope you find the cause. Simon C