Champion Grader - Fuel Gauge Diagnosis Snowballs Quickly!

well howdy viewers welcome back I got a call from a local Road Commissioner and he wants me to look at this old champion motor grader the original complaint was that the fuel gauge doesn't work and what he told me on the phone is that he turned the key on and the fuel gauge just pegs the the needle pegs all the way past fall he replaced the sending unit and replaced the gauge in the cluster and it still has the same problem so let me catch you guys up a little bit it finally cleared out in here and I can make a little bit of a video when we came to work on the machine the batteries were completely dead so these are the two batteries right here 12-volt batteries hooked up in parallel and we hooked up a battery charger this battery charger right here to the batteries to charge them and it immediately pegged the amp meter on the on the battery charger and trip the thermal overload you know basically shut the battery charger down so I figured immediately we had some kind of a major short in the electrical system so I started snooping around and and taking things apart and let me show you what I found this right here is the main cable that runs from the alternator to basically back to the battery so that's your main charge wire that's a 4 gauge American wire gauge wire right there and it's completely melted melted all the insulation completely off of it for the whole length of the wire I also found that this wire right here which is a ground strap running from the bed from the starter to the engine block was completely melted and this starter has isolated field winding so it doesn't ground through the case I believe that's because the starter motor can be indexed on this mounting flange right here so they have an additional connection right here for the field winding and anyway I'm getting ready to replace these wires but I still have something majorly wrong because I get this is the new cable that I made up right here and I get a I get a Archie Sparky whenever I try to touch it to the to the battery so here's what I think is going on I think somebody hooked it up positive ground so this is two wire or two batteries in parallel so it should be 12 volt negative ground so if you look at the starter motor here this big red wire that's the positive battery cable it's hooked up to the field winding and then it runs out to the engine block to the ground strap so yeah if I put a meter on this thing right now and I check from negative battery terminal to this field winding it's 12 volts that that's the positive right now so I don't know what's going on if somebody replaced this starter and accidentally mixed up this connection in this connection I don't know that much about these machines if it was 24 volt I could see it being positive ground but this is a 12-volt machine I'm sure if it the alternator says 12 volt right on it as well and these battery cables certainly haven't been tampered with so I think there's more to the story anyway I called the dealership to see if I can get some service information about this and I'm just waiting for a call back that's when I decided to get the camera out so but it might be something interesting for you guys you well I'm just not able to get any service information about this machine champions like a an orphan child supposed to be part of Volvo I called the Volvo dealer apparently they're only the dealer for Volvo compactors so anyway I called a local shop that does automotive electronics he's basically an expert about alternators and starters he said there are no Delco 24 SI alternators he's aware of that our positive ground he said basically anything built in the last 60 years is gonna be negative ground even if it's 24 volt so that's all I've got to go on for now all right I went ahead and switched the negative cable down here to the field winding and the positive cable up here to the solenoid and I'm ready to try it so we'll flip on the main power here so this is the wire from our alternator I'm gonna just you can see where I've already burned it a little bit with the R key Sparky so let's just see what happens here go fire extinguisher yeah that's a whole lot better so yeah I think there's a chance that it might not have killed the alternator I guess we can hook it back up and start it and see what happens okay well like I said I'm not an expert about champion motor graders but let's see what happens here [Laughter] well the fuel gauge works again man unbelievable okay let me button this thing up and I think we got it licked I've never run a motor grader how do you do it yeah you have to have eight hands buttons and levers everywhere in this thing [Music] you okay well doesn't work what leader doesn't work water temperature doesn't work but I've got that one unplugged so maybe I need to plug those all in and see if we get those back maybe we're just missing the ground on that string but the fuel gauge works well that turned out to be kind of fun how often do you go out to diagnose a fuel gauge and you find out that the alternator wire has turned itself into a seven foot long heating element and the machine is actively trying to burn itself down it's the first one for me so you guys want the rest of the story because there's always more to the story I was standing there with the guy who's in charge of the machine and I showed him the two wires I found on the starter motor and I said you know this one's supposed to be here and that one's supposed to be over there he looks tired that mean I could just see a light bulb just go off in his head and he says oh yeah we had the starter motor out of there last week to change a hydraulic hose I must have hooked him up backwards so yeah crazy so I have one more thing to say and that has to do with professionalism and professional courtesy and it's the way I would handle a job like this so when it when a customer calls you to do a job you got to understand that especially a repair job that most likely somebody's already been there before and there's been many hands on the thing you know this machine is 40 years old it ain't our first rodeo so your job as a professional is to find the problem and fix the problem and my suggestion is when you find the problem that you keep your trap shut about it because nobody likes a know-it-all so when you find the problem you call the customer you say hey customer this is what's wrong and this is what it's gonna take to fix it you don't fly off the handle and say awesome screwed this up and I can't believe this is this was done this way and whoever worked on this as an idiot you know know most likely the guy who worked on it it's a guy who's paying you to fix it what was done before you got there is none of your concern your job is just to fix the problem as it currently exists most likely they know they did something wrong and you know nobody wants to be wrong and most of all nobody wants to be told that they were wrong so just keep it under your hat it doesn't do you any good to to fly off the handle about what you found or you know it's not gonna prevent it from happening again in the future I guarantee you that so just do your job get paid and move on to the next one so I guess that's it kind of an unusual video not a whole lot of meat to it but I thought it was interesting so I probably will post it thanks for watching

Channel: Watch Wes Work

Views: 104,338

Rating: 4.958796 out of 5

Keywords: champion, grader, motor grader, maintainer, road grader, volvo, 740a, cummins, electrical, fuel gauge, wiring, 12 volt, 12v, 24 volt, 24v, fix, repair, mechanic, electrician, fire, burn, melt, short, short circuit, heat, hot, harness, mistake, starter, starter motor, alternator, professional, wrong, test, meter

Id: qWSIR2KQBFs

Length: 9min 16sec (556 seconds)

Published: Fri Oct 18 2019