Bobcat T770 Electrical Problems And Solution The bobcat is an overhead crane that is perfect for lifting loads. If your bobcat crane is not working properly you should take it to a qualified and professional technician who will be able to recognize the cause of the problem and fix it promptly and efficiently. The bobcat cranes are best known for heavy-duty operations.
Fuel gauge not working
I have a Bobcat T770 track skid steer and the fuel gauge is not working. I had the fuel tank replaced, but the gauge still does not work.
I changed out the fuel sender unit with a known good one and when I turn on the key it reads almost full, then goes to empty.
Excessive black smoke on the right side of the engine
The turbocharger is the first step in a chain of components that can lead to excessive smoke. The intake air filters, wastegate or actuator, exhaust manifold, and other system components are all in line with the turbocharger. A faulty part in any one of these locations will cause excess black smoke to occur.
A wastegate is a bypass for exhaust gases. It helps control the boost levels being sent to the engine. Too much or too little boost will cause black smoke from the exhaust pipe.
An intake air filter that is dirty or damaged can cause black smoke problems. Dirt and debris can clog an air filter, preventing enough air from reaching the engine cylinders.
Cylinder #5 misfire code P0305
The P0305 code means that cylinder 5 is misfiring or is randomly misfiring. Start by checking for intake leaks and if no leaks are found the next step is to replace the spark plugs on cylinder 5. If the problem persists more tests need to be done to diagnose the problem, see “Possible Causes”.
The P0305 code means that cylinder 5 is misfiring or is randomly misfiring. Start by checking for intake leaks, intake gaskets are common causes of multi-cylinder misfiring. If no leaks are found the next step is to replace the spark plugs on cylinder 5. If the problem persists more tests need to be done to diagnose the problem, see “Possible Causes”.
Two wires on the injectors run back to a harness
bobcat T770 Two wires on the injectors run back to a harness. One wire is a 12-volt power, and the other is ground. The ECM supplies 12 volts to the injector power whenever the engine is running. The ECM grounds the injector when it wants fuel injected for that cylinder. If you have no voltage, you have a problem with your wiring or the ECM.
The injector has two wires because it is actually an electromagnet. When 12 volts are applied to the injector, it creates a magnetic field that closes the valve in the injector and allows pressurized fuel to spray into the cylinder. When no voltage is supplied, there is no magnetic field, so no fuel can spray.
The connector had been cut and part of it was missing
bobcat T770 The connector had been cut and part of it was missing when I bought it. The machine had a pin under the seat for remote hydraulics and the male end was in the dash so it was obvious that something had been removed to make the machine not work with a trailer.
I purchased a new control valve assembly and plugged it in. It seems to work fine but there is no wiring diagram on the system. I can not find anything online or in my shop manual either. I need to know which wires go where and how they hook up so I can use this circuit with my trailer.
The fuel gauge shows empty when it has a full tank
The fuel gauge sender is located in the fuel tank and is connected to the fuel pump. It also contains a float that moves with the fuel level. As the float drops, an electrical signal is sent from the resistor to the gauge.
The fuel gauge sender will have a wire connected to it and will have a ground wire attached. The ground wire and send wire need to be disconnected. Use a test light on both wires and check for power and ground.
If there is power on both wires, then you have a bad sender unit in your tank. If there is no power on either wire, you may have a bad ignition switch or an open circuit in your wiring harness between the sender and the dashboard.
We replaced the fuel level sender and that fixed the problem
Problem with bobcat T770 fuel gauge. The gauge was reading the fuel was about half full all of the time. When we took out the sending unit, it had been leaking gas and there was a lot of debris around it. We cleaned out the fuel tank and cleaned up the sending unit and put it back in. The problem continued. We replaced the sender with a new one and that fixed everything. Some people say that you don’t need to replace the sending unit, but we did because there was no way to clean it out properly with all of the nooks and crannies in it.
After some research, we found this to be a very common problem with Bobcats in this series
bobcat T770 After some research, we found this to be a very common problem with Bobcats in this series. The problem is caused by the fact that the solenoids that control the 2-speed travel function are connected directly to the battery and are not fused at all. This causes the wires to melt together and short out when the power is off. Once they’ve melted they stop working and you have to replace them. The good news is that it’s an easy fix and only takes about 30 minutes to complete.
The injector is not firing but no power is reaching it, so it must be the wiring harness or computer causing the problem
The injector is not firing but no power is reaching it, so it must be the wiring harness or computer causing the problem. A mechanic has to troubleshoot this.
Injectors have a single electrical connection to supply fuel and a second wire that monitors pressure in the fuel line. The injector may have a seep or leak that allows fuel to escape and allows air into the line. The air bubbles cause the pressure in the fuel line to drop, which triggers the warning light on the dash. The light remains illuminated until the pressure reaches a level that indicates there are no leaks or seeps.
The injector may also be clogged due to water or other foreign particles in the fuel line. It’s possible that the injector is open, allowing increased flow through it when there is no pressure and then closing when there is pressure. When this happens, you typically see an increase in fuel consumption.
It’s also possible that there is damage to one of the wires inside of the wiring harness, which may require an inspection of each wire in order to locate it.
We tested for power at pin 5 of both injectors (power is supplied from “F”) and found both were OK
bobcat t770 We tested for power at pin 5 of both injectors (power is supplied from “F”) and found both were OK. The resistance of the primary winding was 0.5 ohms and the resistance of the secondary winding was 5.6 ohms. Both readings are within Bobcat specification.
bobcat t770 We then checked for power at pin 8 of the injector (power is supplied from “G”). No power was present at either injector. We traced back to pin 35 of the computer, which is where “G” gets its supply voltage and found no power there either. We then checked for power to pin 2 of the computer, which is a red wire that supplies this circuit with 12 volts and found it had 12 volts present. This means that the computer was grounding this circuit when it should have been energized.
bobcat t770 Using a scan tool we commanded the computer to energize this circuit and found it did so normally, which confirmed that our problem was in the computer.
Bobcat T770 electrical problems can be solved by doing some tests and also by replacing some
If you have a Bobcat T770, you have no doubt experienced the occasional electrical issue. But did you know that these Bobcat T770 electrical problems can be solved by doing some tests and also by replacing some parts?
In this article, I’ll show you how to do both. Before we start, however, I need to make a disclaimer. This article is not intended as a substitute for professional electrical advice or services. It is meant only as an example of one way to troubleshoot and repair your Bobcat T770’s electrical system.
If you have any questions about the information in this article or about the products or procedures mentioned, please contact your local dealer for more information. If you need help finding a dealer near you, visit our Find A Dealer page. Now on with the show!
