Volvo G976 diagnostics

Howdy folks, I’m having a very random but becoming chronic issue with one of my 976 graders that acts like it’s running out of fuel but other than the emergency brake / emergency steering Hyd supply alarm it gives no codes to the DIC so I would like to hook up a laptop / scan tool and watch some things - any of you guys have one that you know works on the construction machines? I have access to a Jpro system laptop which covers all makes of commercial on road - but I cannot get a clear answer from searches if that is going to work on a motor grader. Thanks

This machine 2010 G976 @11k hours on it, has recently taken up a bad habit of cranky starting, once its running, its good. Not a bunch of smoke or anything abnormal. Warms up ok, make a lap or two around the yard. Then about a 1/4 mile down the highway it will just shut off like the key was switched off. You lose everything. Wait a bit and crank it up and take off again. It will run the rest of the day. We have been crawling thru this machine and not finding anything wrong. Thought I would hope to hook up a laptop and watch it die - in real time maybe see whats forcing the shutdown or something. Its not giving any codes that lead us to a problem.

Blue-Fox said: This machine 2010 G976 @11k hours on it, has recently taken up a bad habit of cranky starting, once its running, its good. Not a bunch of smoke or anything abnormal. Warms up ok, make a lap or two around the yard. Then about a 1/4 mile down the highway it will just shut off like the key was switched off. You lose everything. Wait a bit and crank it up and take off again. It will run the rest of the day. We have been crawling thru this machine and not finding anything wrong. Thought I would hope to hook up a laptop and watch it die - in real time maybe see whats forcing the shutdown or something. Its not giving any codes that lead us to a problem. Click to expand... If it has an electronic engine with both crank and cam sensor, it is possible one is communicating incorrectly with computer without dropping any DTC for you to see. Have watched a couple of video's that highlighted that they can fail and not log a code. The guy disconnected one at a time and seen what happened, found out the camshaft sensor was faulty. Have you checked your relays with them removed from machine and powering up a 5-10 amp bulb for 10-20 minutes to see if they start to get hot and suddenly drop out. Check each leg of ATO fuses to make sure the receiver from one is not loose and causing the computer to shut down instantly. Check all the power relays for loss across the two sides. Test for AC ripple voltage coming out of your Alternator because computers do not like it, but some will shut down if dosed with too much AC ripple voltage. If you are going to test for it, do it when the engine is super hot and there is lots of extra electrical load as some faulty units only put out excessive when hot. Often I find alternators full of dirt that I blow out with 150 psi of air, but be careful if the output post is live and uncovered. My guess is something is dropping out under load when very hot, maybe it is not hot and still drops out? Simon C

Simon, thanks for the serious reply, Im pretty new to computer controlled equipment so this is a big help. This change came along after an alternator failure, and it took 3 of them from the dealer to get one that worked.

Could the voltage regulator be set too low? I've read the Champion 8400 trans. was very sensitive to low volts. Maybe the Volvo engine control is too. Really sucks that Elvaan/Jade went under.

Blue-Fox said: Simon, thanks for the serious reply, Im pretty new to computer controlled equipment so this is a big help. This change came along after an alternator failure, and it took 3 of them from the dealer to get one that worked. Click to expand... I would check your Charge cable coming off the alternator in case it goes through some plug- in, which is possible. Is this a 12 volt or 24 volt system. I am guessing 24 volts but have never worked on one. If you have any Cole Hershee Self resetting breakers on the unit they have to be load tested off the unit to find out if one is dropping out and then resetting itself. I had an alternator that was giving me grief years ago that would drop out when hot and then was fine when tested cold. Company would not let me be at truck when it returned hot late every evening till one day I was on overtime doing another job and jumped on it hot and guess what, it was dead , not charging. That was like three weeks of boosting evry morning figured out. Simon C

Welder Dave said: Could the voltage regulator be set too low? I've read the Champion 8400 trans. was very sensitive to low volts. Maybe the Volvo engine control is too. Really sucks that Elvaan/Jade went under. Click to expand... You are close, The first replacement alternator was a reman and was sent back for low volt output, indicated by the DIC panel code for low volts and "charge" alarm on the DIC....

Blue-Fox said: You are close, The first replacement alternator was a reman and was sent back for low volt output, indicated by the DIC panel code for low volts and "charge" alarm on the DIC.... Click to expand... You could of gotten a couple of dud alternators, but I would load test the cable from the output to the eventual Battery Positive ( sometimes via a connection at Starter Positive, or through some shunt somewhere up near control panel ) . Have seen quite a few that the dash was saying no charge or low charge that a clamp meter at alternator and Multimeter at Alternator proved otherwise. We are not there and only assume that you have tested all correctly. Went to a job yesterday with no start on Deere 200 excavator, that the batteries are all good and fuel pump problem. I decided I need to see the Batteries under the cover and right away Positive output cable full of green going into cable. Had to change all the cables. It was cranking before but weakly. Then still no start, no fuel at all in secondary filter and primary plugged. Installed 2 new filters and after pressurizing tank and bleeding filters it roared to life. Different situation than yours but same idea. He was pretty sure a fuel solenoid on pump problem. I have learned over the years to double check all that I have checked in case I missed something. I don't know you at all so just in case you missed something that I could miss also how have you tested the Alternator circuit. Maybe we can help. Simon C

I must say that Simon is very knowledgeable when it comes to electrical/electronics on equipment. He's knowledgeable in most types of repairs but was a big help when I needed some electrical assistance. Told me how to make a simple tester using an ATC fuse holder to see how big a fuse I needed.

Hi All, I have a Deere JD770G grader, with worn out Circle drive teeth. I have established that there are two option, Option 1 is to replace the complete circle frame (More costly) or option 2 is the replacement of worn segments, which require some engineering, to cut our worn segments and replace with new. If anyone has had experience with option 2, I would be grateful for your recommendations on best practive to perform the job.

Maybe repost a new Heading such as ( John Deere 770G Circle Drive Repair Question ). It will get more views and more correct information. Someone will respond Post Serial number of machine as well in case there is some differences. Simon C

Simon C said: You could of gotten a couple of dud alternators, but I would load test the cable from the output to the eventual Battery Positive ( sometimes via a connection at Starter Positive, or through some shunt somewhere up near control panel ) . Have seen quite a few that the dash was saying no charge or low charge that a clamp meter at alternator and Multimeter at Alternator proved otherwise. We are not there and only assume that you have tested all correctly. Went to a job yesterday with no start on Deere 200 excavator, that the batteries are all good and fuel pump problem. I decided I need to see the Batteries under the cover and right away Positive output cable full of green going into cable. Had to change all the cables. It was cranking before but weakly. Then still no start, no fuel at all in secondary filter and primary plugged. Installed 2 new filters and after pressurizing tank and bleeding filters it roared to life. Different situation than yours but same idea. He was pretty sure a fuel solenoid on pump problem. I have learned over the years to double check all that I have checked in case I missed something. I don't know you at all so just in case you missed something that I could miss also how have you tested the Alternator circuit. Maybe we can help. Simon C Click to expand... Pretty sure I had a DUD mechanic (fake it till you make it) at the same time, he was getting reman units instead of a brand new one and the brand new one was the answer. BUT I'm still not convinced that this one is good, I just watched some vids about the AC ripple that you mentioned and it really acts like that is whats going on. Theres no DIC code, no alarms, (just dies like you shut off the key) and we did put a new key switch in this machine trying to eliminate that possibility.

Welder Dave said: Could the voltage regulator be set too low? I've read the Champion 8400 trans. was very sensitive to low volts. Maybe the Volvo engine control is too. Really sucks that Elvaan/Jade went under. Click to expand... Dave, I believe these units today are all self / internal regulated unlike older American stuff that had a pot screw or ways of ajusting voltage (Leece Neville, Delco,etc...) Have you heard anything further about Jade? Was there an auction and its all gone now? Or maybe just moved somewhere else to start back up? They are a huge loss to the motor grader community.

There was an auction earlier this year I wish I knew about. Info should come up if you google it. It didn't list the items just when it happened. I might have bought some spare parts. I was shocked when I saw Elvaan/Jade went into receivership and the receiver had the auction. Even knowing one of the mechanics would have been a great help.

JoesJD315SE4x4 said: Hi All, I have a Deere JD770G grader, with worn out Circle drive teeth. I have established that there are two option, Option 1 is to replace the complete circle frame (More costly) or option 2 is the replacement of worn segments, which require some engineering, to cut our worn segments and replace with new. If anyone has had experience with option 2, I would be grateful for your recommendations on best practive to perform the job. Click to expand...

1. I'd appreciate that you will start your own thread conversation where you will be "on topic" That really helps people searching for answers to limit the off-topic text.
2. You'll get better responses that adresss your question.
3. My answer to your Q, It just depends how badly the teeth are worn, when its just a tooth or 2-3 maybe its easy to just make a template of a good tooth set (in the back of the circle) and then weld up/ grind / fit the worn out teeth back to the original shape and tolerance.

Welder Dave said: There was an auction earlier this year I wish I knew about. Info should come up if you google it. It didn't list the items just when it happened. I might have bought some spare parts. I was shocked when I saw Elvaan/Jade went into receivership and the receiver had the auction. Even knowing one of the mechanics would have been a great help. Click to expand... I dealt with "Guy" in the shop and Elmer Whiskeyjack was my parts guy. Both top shelf.

Blue-Fox said: Pretty sure I had a DUD mechanic (fake it till you make it) at the same time, he was getting reman units instead of a brand new one and the brand new one was the answer. BUT I'm still not convinced that this one is good, I just watched some vids about the AC ripple that you mentioned and it really acts like that is whats going on. Theres no DIC code, no alarms, (just dies like you shut off the key) and we did put a new key switch in this machine trying to eliminate that possibility. Click to expand... Not sure if you have a Pull solenoid on the fuel pump, if you do it could be removed and tested live off your batteries, with a heat gun getting it pretty warm like 200 F to see if it drops out. Under covers is not at all the same as with the covers open and the big heat of cruising in the engine compartment not there. When you are running down the road there is a lot of heat under those covers. Some relays have been known to drop out, and testing for AC ripple voltage is best done with a wrapped cable attached to the Alternator output post with an end of it sticking out a cover so that you can test it the way the alternator is under the covers not opened up and cooling off. On a long up hill run with you just pulling over and running back with all the electric fans and lights on and the engine revved is a real test of if something is happening under heavy heat. It can be a real pain to find what is dropping out under load and heated. Parts or time is the only solution I know of, and keep a list of all you have done properly so that you don't second guess yourself. Simon C

Blue-Fox said: I dealt with "Guy" in the shop and Elmer Whiskeyjack was my parts guy. Both top shelf. Click to expand... I've dealt with Elmer in parts too (you remember his last name) and the new manager after it changed to Elvaan. I appreciated the manager talking to me and even consulted with the shop foreman. Before the name change trying to talk to someone in service was near impossible. I couldn't even get what they charged per hour which I thought was strange. Did they charge different customers different rates?? Thought things were really improved only to discover they weren't. It does suck!

Blue-Fox said: Dave, I believe these units today are all self / internal regulated unlike older American stuff that had a pot screw or ways of ajusting voltage (Leece Neville, Delco,etc...) Have you heard anything further about Jade? Was there an auction and it’s all gone now? Or maybe just moved somewhere else to start back up? They are a huge loss to the motor grader community. Click to expand... A few guys claimed to have bought up quite a bit of their items but so far I have found them somewhat uninterested in selling any of it even though they have posted places they have stuff to sell. I have a few Champion/Volvo parts I picked up at a local government auction clearing out their old parts stock pile. Steering motors, some electrical solenoids and such. Lots of seals and bearings. There is Grader Pro out of Quebec but I’ve never dealt with them and I imagine the shipping would be pretty high on anything of weight.

Simon C said: Maybe repost a new Heading such as ( John Deere 770G Circle Drive Repair Question ). It will get more views and more correct information. Someone will respond Post Serial number of machine as well in case there is some differences. Simon C Click to expand... Thanks Simon, that sounds like good advice