D6R intermittent fault

[D8 Ump]

Hi all, my d6r dash lights and gauges sometimes don't work.The tractor starts and runs fine but nothing on the dash works! When this happens I just let it tick over for a short while then stop it and restart it.This sometimes works.The charging light on the dash is also not working other than when the first switch on of the key when it lights them all up.Had the alternator cheched and that is OK. Batteries are in good shape and all fuses seem good.Any thoughts?

 

[Nige]

Does the self-test (all gauges sweep full range, all warning lights come on, & the warning buzzer sounds) work when you first switch on..? If so that means the gauges themselves are OK.

 

[D8 Ump]

Yes all the lights on the full sweep and buzzer work then its just the oil light and parking brake stay on.Then when it is being awkward nothing works.

 

[Nige]

I would say that you most likely have a dodgy wiring harness connection in the back of the dash panel. It will probably get worse rather than get better so it might be worthwhile investing some time in opening up connectors, cleaning, and refitting. There is a 6-pin connector right at the back of the gauge cluster - I'd start with that. It might also be worth investigating the Harness Code plug.

There are a million and one different versions of D6R, what's your Serial Number prefix..? If you want an Electrical Schematic send me a PM with your email address and the full S/N of the machine.

 

[Bob/Ont]

Just a thought, try running the heater/ac blower when it acts up. That will put a high amp electrical load through the cab harness. If the problem is a bad ground the blower will not work. Have had this happen on a 973C, ground cluster was tight and the cab had a well connected ground strap but some how the connection between the right and left sides of the cab not good. Made a new ground wire from cluster to machine frame and it worked okay. The cab looked better than it should have for age of machine, I suspect it might have been a fire damaged repair, don't know for sure.
Later Bob

 

[Nige]

I picked a S/N prefix at random and the one thing that struck me about the electrical schematic was the number of ground wires that all met at a few (can't recall exactly how many) splices inside the wiring harness, the gauge cluster ground being one that was spliced into a big bunch at one point. I hope it's not one of those splices acting up or diagnosing it could be a real pain.

 

[Cmark]

On the 6R the main relay and fuse panel in in the battery box and is susceptible to filling up with crud and then corroding out various things. I suggest you take a look in there as well.

If the problem is in there tha can remove t' panel as a unit to clean it out and repair it on t' bench.

 

[68M]

Most Cats these days have a solenoid that runs most of the electrics. When fault they work intermittently. Often if you turn the key off and on, before starting you will find your dash (and everything else) may work. we've replaced quite a few of these in diggers, dozers, dumpers & scrapers.

 

[D8 Ump]

Thanks for all the tips. The serial number is 8tm 00754 so its an early model. I baught a service book for it when I got the machine thinking everything would become clear and I would understand the whole thing. I might as well have baught a book on brain surgery! I think I will ask a chap I know that is good with electrics to have a look. Will keep posted with the outcome .Thanks Ump

 

[Andy McBride]

I would say that you most likely have a dodgy wiring harness connection in the back of the dash panel. It will probably get worse rather than get better so it might be worthwhile investing some time in opening up connectors, cleaning, and refitting. There is a 6-pin connector right at the back of the gauge cluster - I'd start with that. It might also be worth investigating the Harness Code plug.

There are a million and one different versions of D6R, what's your Serial Number prefix..? If you want an Electrical Schematic send me a PM with your email address and the full S/N of the machine.

I am having this problem. How do I clean these tiny holes and tiny probes once it it disconnected

 

[Andy McBride]

Most Cats these days have a solenoid that runs most of the electrics. When fault they work intermittently. Often if you turn the key off and on, before starting you will find your dash (and everything else) may work. we've replaced quite a few of these in diggers, dozers, dumpers & scrapers.

I am having a similar problem. Which solenoid and where is it located?

 

[Nige]

I am having this problem. How do I clean these tiny holes and tiny probes once it it disconnected

Aerosol contact cleaner and compressed air to dry it I would suggest.

 

[Andy McBride]

Thank you. I will try that.

 

[tctractors]

I am having a similar problem. Which solenoid and where is it located?

Thanks for all the tips. The serial number is 8tm 00754 so its an early model. I baught a service book for it when I got the machine thinking everything would become clear and I would understand the whole thing. I might as well have baught a book on brain surgery! I think I will ask a chap I know that is good with electrics to have a look. Will keep posted with the outcome .Thanks Ump

The 8TM Series D6R suffer in a few spots with wiring drama's, the first is with the batteries removed you will see a wiring loom go down the side of the chassis towards the implement pump so you will also need to pop the floor plates to follow it from the left hand side the wires can rub through, the next nasty spot and possibly the culprit is a connecting plug where the wires go up to the dash panel so it's right hand door open and a small panel nearest the cab to remove, the connection can be a fiddle to mess with but is often found with burnt or rotting contacts, as your sat in the seat looking behind the removed dash it's on your right, if you have a problem all the wires are number traced marked so feel free to call me if you need any info as I do have the complete wiring diagram in Big, it's also a good thing to check the Fuel air ratio control on the 3306, this is the steel pipe off the inlet down to the control as they are often damaged in the P clip area, I also check the rubber bit in the control as they don't last long. tctractors p.s. as already said the fuse panel is a good place to start, there is only 1 or 2 fuses that could be causing your fault, well 1 really but you never know.

 

[Nige]

Thank you. I will try that.

It might be an idea to post your machine Serial Number so everyone knows what you are dealing with. There must be 50 different models of D6R in existence.