Moved D3G from one site to another, rain moved in for a week and then moved back out so the unit sat still for roughly 10 days. Went to use it Wednesday and the park brake engaged 2 times in the first 5 minutes of use. Played with park brake switch and went back to pushing each time and the 3rd time it engaged and died. Wouldnt start. Trouble shooting methods so far have found that the Key Fuse in the panel has 12.5v with Key off. As soon as you turn the key on, voltage drops to 4.5v. Try to start and it wont do anything. Sometimes the gauges/lights illuminate as soon as the key is turned on, sometimes they are delayed in coming on up to 30 seconds. Thus far we have tried - Pulled both batteries and load tested. - Pulled each fuse 1 at a time with key on to see if voltage returns to 12v - Tested voltage at the back of the key, same results, 12v key off, 4.5v key on (Brown Wire on key switch) -Cleaned motor/frame ground strap ends -Cleaned master switch/frame ground end -Bypassed master switch -Disconnected Altenator All resulted in no change We have put a wire (with inline fuse) from the positive battery terminal to the ECM fuse and the dozer will crank and operate normally but I would like to find this issue and fix it correctly. Thank you
I hope you're wrong
First of all I am so far from being a mechanic it's silly for me to give any advice in the first place but I do have some experience with the G series dozers and their finicky affliction to voltage. Assuming the load test on the batteries were good - a bad battery caused the same issue with us once on our D5G Have you checked the alternator output? - an under performing alternator caused that issue again on our D5G Have you replaced the park brake switch? - had a faulty switch cause the same as well Unfortunately that's all I have experience wise. This problem is no joke trying to grade in high speed across a site and the park brake slams on.
Yessir both batteries did test good on load test and multi meter reads a steady 14.X volts or so at the battery terminals while running. I have not replaced the switch only because with the jumper wire feeding the ecm fuse, the unit functions normally: Park switch, lights, guages, radio, a/c, everything
Additional info. Key on with 4.5v A/C blower works correctly, radio works suggesting they have full 12v power
If an electrical schematic would be of any help to you please post a Serial Number to identify the correct one. Do you know how to access Diagnostic Codes using a short piece of wire and the Harness Code connector.? That would probably be a good place to start. Any specific Code could direct you where you need to be inspecting.
Do yourself a favor Check the codes
I do have an electrical schematic for the machine but I am unaware on how to check for codes
CAT00D3GPBYR01842
So I have found how to retrieve the codes in another thread using the wire Mr. Nige. It says the red light will flash. So how do you read the code via the light? Count the number of flashes?
See the attached article. I think it ought to explain how to decipher the flashes.
Thank you, Nige. I will report back
Ive also got a roller that started showing out also. I started a thread in the roller section but if anyone may could help with a wiring schematic for a Volvo DD24 it would be great. The roller section doesnt seem to get quite as much attention
I cant figure out how to get the codes still. Key is off, I unplugged the connector in the fuse panel and jumped from pin 1 to pin to and I dont see any light come on
Code 144. Magnetic switch [start relay)
Is that the only one.? Have you tried putting a jumper wire between Pins 1 & 2 and see whether or not there are any more Codes.? The Codes do not "scroll" automatically. You have to manually "increment" them from one to the next.
The Start Relay may be the cause, because it also powers the ECM. See attached. There are three possibilities. I have included them all but a lot of the tests are common to all three. It should help you find where the problem is. Personally I would not simply replace the relay straight off, you could just as easily have a wiring fault.
Thank you Mr. Nige. I will take a look into the file as soon as Im home as it wont pull up on my phone. In the meantime, the dozer had been operating correctly with our jumper wire setup. The operator went to change his speeds and the machine died out again. Tested key fuse with key off now at 4.5v. Turn the key on and it drops to 1v or less at the fuse. No dash lights or even hour meter readout at this point. So at this point now that it has died while i had 12v jumped to ecm fuse. we now have 5v key off, .5-1v key on. I can stick 12v to the key fuse and everything comes on. (This is how I was able to pull codes finally). I can remove the 12v wire from the fuse after approximately 10 seconds and the fuse will maintain 11-12v key off.
You have the schematic. The best I can suggest is to follow the power starting from the battery and working downstream from there. Any point where you have 12v you need to go further. When you reach a point where the last voltage you measured was 12v and the new measurement is 5v, 1.5v or whatever, then your problem lies between the point at which you are measuring now and the last one.