I found this forum by searching for an issue related to the parking brake not releasing on a 2003 Cat D6N (Ser#ALY00676) when put in gear. I did read the thread I found here where the issue seemed to be the problem I am having but I am having difficulty in locating a part number for a wiring harness and part. Let me start by saying that I have never worked on a dozer and am having a tough time locating the parts on the diagrams. The dozer belongs to a relative and I would like to get it running to use it to clean some land that is being clear cut. Our situation is similar to the other thread in that a Cat tech came out and the diagnosis was that the final drive pump was bad and that was $2500. The cost for them to repair was $8k. We did some more digging and have found a wiring harness that has the wires exposed and bare. One of the plugs was broken so I am not sure that the problem is the pump. I will attach some pictures of the wiring and the part that had the plug broken if someone could point me in the right direction to locate these parts so I can get an idea of what it may cost. The third and 4th picture is the part that the plug in was broken and it is located under the driver seat. The first 2 pictures is the wiring harness at the back of the dozer.
G’day and welcome. Kudos for supplying a machine Serial Number, it makes looking up information so much easier. That wiring harness has certainly seen better days. I will try to find the Part Number and post it up. There also may be other problems on the machine. I’m assuming that it has power on it. Can you tell us what happens to the SERV CODE icon in the RH side of the digital display window on the dash when you turn on the key. Does it go out after the system has completed the initial self-test or does it stay on.?
That's the brake control valve. Do you have some photos of the broken plug.? If it can be identified I would say it is likely to be available as a spare part at a reasonable price. Replacing it should not be difficult. The wiring harness Part Number you are searching for is 213-2982. The problem is that it is a VERY large harness and connects the all the components of the operator platform including the transmission. If you ask for a price on it make sure you are sitting down first. The upside is that individual repair parts such as plugs/connectors are availale for it. See below. If there is enough slack in the harness it might be possible to repair by cutting the damaged wires and installing a new 17-pin connector. You would need to be very careful in making sure each of the 15 wires was installed in the correct pin of the new connector. It will also require new pins crimped on to the end of each wire. Unfortunately I don't have details of the pins. Maybe someone else has an idea.? That plug is a MIL 3108 type. The Cat Part Number for it is 4W-4293. Also see this link - https://www.amazon.com/GXMRHWY-MS3108A20-29S-Female-Electrical-Connectors/dp/B0C58NHRX7
Can you post a link to that thread so we can all see it.?
These might be useful.......... https://www.amphenol-aerospace.com/blog/amphenol-connector-reference-guide-volume-1
Thank you Nige. The machine does have power and will crank but the pump that Cat diagnosed as being the problem was removed. I am working on getting it put back in between work and farm chores and I don't remember what the dash looked like the last time it was cranked. The wiring harness is in bad shape and some of the wires have been spliced back together. The wires under the seat are in similar condition so I am sure that these harnesses will have to be repaired or replaced. Correct me if I am wrong but is it not possible that with the wiring being bare and exposed make it almost impossible to diagnose the pump as the problem? It would seem that with the bare wires coming into contact with each other it would create a short and not send correct voltage to the solenoid. I will get a picture of the broken connector harness today and post it.
HeavyEquipmentForums This is the link of the thread that brought me to the forum.
It certainly doesn't help. IMHO your first priority should be to get the pump reinstalled and everything hooked up mechanically. At that point the electrical system can be diagnosed. Get that 100% sorted out and then move to the mechanical side. At least that's how I would attack it. EDIT: Having read through the thread you linked brought it all back. More than a few rabbit holes were explored in great detail in that thread.... I would DEFiNITELY want to get the electrics correct before touching anything mechanical.
Thank you very much Nige. That is what I will do. I have attached some pictures of the sub harness that was under the operator seat with the broken plug that was connected to the brake control plug. I am planning to get the pump put back in this week.
I thought you meant one broken connector......... Personally I would replace that harness completely. As it's short it should not be too expensive, although it will still probably be more expensive than you imagine. The harness Part Number is 201-8772 (Steering Solenoids). You may have to be careful installing the replacement because it appears as though the 2 x 2-pin and 2 x 4-pin connectors may well swap position with one another if the harness pigtails are long enough. Also note that there is a "leg" with a 2 pin connector on it that is not used. It's there zip-tied to the harness in your photo. Beware it may not be assembled like that on a replacement harness. It would pay you to identify all the connectors by wire numbers and colours to ensure you get them hooked up correctly. Last thing when you install the new harness. If the ladder clips #31/32 where the zip ties to hold the harness should be fitted are not installed on the machine, then replace them.
I should have mentioned that the harness looked as bad as the main harness. I did find that part and was shocked that it was only $130. My sons and I spent most of the afternoon cleaning up the pump and hope to start getting it put back in tomorrow. I think we found the part number for the brake control valve as the connector broke off of the valve when the harness was disconnected. The part we found is 174-4909. Once again, the price was lower than expected, $284. I will check with the Cat dealer about those parts and keep you posted on how things are going. I really appreciate the help you are providing me
I assume that the electrical connection on the coil is what was broken. The coil is actually available separately under the Part Number 323-9531. See the attachment. It can be replaced without removing the solenoid valve from the machine simply by unscrewing the Nut #3.
You are correct. The electrical connector on the coil broke off when the plug was disconnected. Thank you for the part number. I am planning to start with your suggestions but I was curious, should it come to that, does the cab have to be removed to replace the main harness you sent me the part number for? From looking at the routing through the back and under the operator station, you are not able to see but a small part of that main harness.
It would probably be easier with the cab removed but "where there's a will there's a way" and I'm fairly sure it could be done with the cab in place. Ideally you need a very small person to get down into the Hell Hole under the cab floor. Before you contemplate replacing that harness I would first ask Thompson Tractor for price and availability, and be sure you are sitting down when you ask. I'm betting on North of $1500, probably well North......
You are correct about that harness. I looked it up on the app and it shows the complete harness at $2584. I did get some more information from the family member that the dozer belongs to and he said that the brakes are released in neutral but when it is put in gear it locks the brakes. He said that the issue came on slowly and progressively got to the point that it is at now. I am hoping to not have to replace the complete harness. I am starting with your less expensive suggestions to get it where we can turn the key on to find out if any codes or lights are displayed.
Doesn’t surprise me. Once you replace the steering solenoid harness that would be my suggestion. I wouldn’t bother touching the transmission connector just yet.
I had a few minutes today and was able to get a closer look at the transmission connector today and it is in pretty bad shape but we are going to try and make it work for now. We are going to try and separate the wires to keep them from touching but I am not planning to do more than that at this time. I took a picture of the connector today after we unplugged it and removed the electrical tape that had all of the wires packed together.
That looks nasty...! Almost like it has had battery acid spilled on it. Question: Is there enough "slack" in that leg of the harness to be able to cut 3-6" or so off it, crimp new pins on each wire, and install them into a new replacement connector.? TBH for a test I would try to separate the wires as much as possible and maybe try to wrap a bit of tape around them to stop them from touching. The turn the key on and see what the display says for Diagnostic Codes.
It does look pretty bad. It has several places where the wires have been sliced back together but I am thinking that we can get the wires wrapped individually for now.
Maybe now is the time to suggest you read the Click Box thread and get yourself familiar in advance with how Diagnostic Codes are accessed and, more importantly, how Logged Codes can be erased. You can either make a yourself box or use the McGyver solution on Page 3 using two pieces of wire. The famous Cat "Click Box" It is a regular event on HEF for someone to post a question regarding Cat machine electronics, Diagnostic Codes, etc. For a large number of the questions posted the answer(s) revolve around the famous Cat “Click Box”, otherwise known as the 4C-8195 Control Service Tool. This tool usually hooks... HeavyEquipmentForums
I will do that. I did contact Thompson Cat this morning and got the sub harness and coil ordered. They said they should be in Thursday. Headed out now to try and get the pump put back in.
I read over the thread as you suggested and I will admit that I will have to read over it a few more times. We did get the pump put back in late yesterday afternoon along with all of the hydraulic lines reconnected. We are planning to work on those wires at the rear connector today and the parts are scheduled to arrive tomorrow so with some luck we will have everything back together by the weekend.
Nige, we got the parts from Cat yesterday and installed them today. I don't want to break out the champagne yet but I can say that after installing the new parts, the dozer did crank and will go into gear and move. The brakes do not appear to be locked any longer. We were not able to run it very long as there is a hydraulic leak on one of the lift arm hydraulic lines. We did find the hose that is leaking and will get it replaced Monday. We will also have to get some hydraulic fluid as it was not showing in the glass. I was able to get a picture of the lights as you mentioned and there are several that are on (picture attached). I will get a better picture after fixing the line and adding the hydraulic fluid. I am not sure if it related to the hydraulic fluid but with my luck it would not be that easy. I can say that the engine in this machine is new with less than 20 hours on it and runs great. I would like to thank you for your help so far. We would not be to this point without your guidance.
That is good news. So was your photo above taken with the engine running or stopped.? Need that information to figure out which of the warning lights in the panel above are relevant. If you are not in possession of an Operation & Maintenance Manual you really need to get hold of one ASAP .The Cat Publication reference is SEBU7417 and you can download one for $52 from the Cat Pubs web site. However the one thing is that, engine running or stopped, the SERV CODE icon indicates that there is at least one Active Diagnostic Code present in the electronic system. You do not need the engine running to troubleshoot the electronics, stopped with the key ON will be fine. This is where the Click Box thread comes in useful. Go to Posts #50-52 on Page 3. You need to make the "chicken wishbone" wire assembly shown in Post #51 using a couple of 6" lengths of 16 or 18 SWG automotive wire and 3 Deutsch sockets. The Cat Part Number for the sockets is 8T-8730. Also worth pointing out at this point that you will need to buy/borrow a Deustch crimp tool (P/N HDT-48-00) because when you get into repairing that transmission harness you're going to be doing a good deal of crimping. It's not necessary to buy a genuine Deustch tool @ $600, aftermarket versions like this one are available. Here is a link to the Deustch web site. Searching for their Part Numbers will probably throw up cheaper solutions than Cat Part Numbers from your local dealer. the connectors on your machine are the DT type. Deutsch Connector Pins and Sockets Shop Deutsch connector pins and sockets for DT, DTM, DTP, and DTHD Series connectors. Order for assembly, service, and harness repair. www.deutschconnector.com I'll send you some stuff. Keep an eye on your message inbox.
Thanks Nige. The engine was running when the picture was taken. The only manuals I have are the parts manual and service manual. I got those from the family member that owns the dozer and they are on my computer. I may have failed to mention that we worked on the wires at the transmission for about 2 hours and managed to separate all of the wires and get them isolated from each other with electrical tape. We did check all of the wires that were spliced back together with connectors and they were not loose so we put electrical tape on those for now. I will go by the auto parts store tomorrow to get the wire and will get the connectors ordered to make the wishbone as you suggested.
The O&M Manual is part of an OEM Service Manual, but if the manual you have been given is aftermarket it may not have one. The 4-pin Monitor Service Connector is located to the left of the operator seat (View B-B) under the cover #9, directly under the 9-pin circular connector for ET. The fact that there are Active Diagnostic Codes on the Monitor indicates they ought to be investigated. For all we know at this point the Codes(s) may well be related to some/all of the warning lights on the panel. it is relatively easy to relate the wires on the MSC to the pin positions using the illustrations above and relating them the orientation of the lock on the connector. Generally it is installed with the lock at the top but that may not be the case on your machine. Note that the 2nd illustration is looking from the back side of the connector so as you look at it from inside the cab Pin #1 should be oriented top right.
Thanks Nige, I will get the components I need that you mentioned to put together the chicken wishbone. I am planning to get the hydraulic line replaced tomorrow and make sure that we have enough hydraulic fluid in the machine. I will report back with any changes after I have completed that.
Nige, we were able to get the hydraulic hose made and replaced today. We also added some hydraulic fluid and had to put some oil in the engine as well. After doing all of this, we cranked the machine to let everything circulate. I was able to get a video of the panel and was shocked to see that all of the lights were off except for the battery light and the far right bottom light that went off after the emergency brake was released. I am thinking that the battery light may be due to the fact that the dozer had not been cranked in several months. The serv code that was displayed is no longer on the panel. We bolted the floor panels back in, installed the floor mats and seat and plugged the air ride back in and everything is working. I have attached a quick video. We did learn of another issue with the track tensioner but wanted to make sure this was resolved before moving on to it.
I suggest you should buy yourself a lottery ticket. You're never going to get that lucky ever again........... I disagree. The "battery" (actually a charging) light is a reflection of the alternator voltage output. You should investigate the output voltage both at the alternator and at the batteries. It may be nothing more than corroded connections but you need to find out what it is and fix it before the batteires die.
I am thinking the same thing. Thank you for correcting me on that, for some reason I did not even think about the alternator. I will check on that today. As for the issue with the track tensioner assembly, the left side has no fluid in it and the right side is fine. I did use the grease gun and it will tension the tracks. We have tried to find where the fluid leaked from on that left side but have not located anything obvious.
The oil is a damping medium for the recoil mechanism so you really need it in there. Best thing I can suggest is to top the oil up to level (It might have a dipstick built into the 4-bolt cover) and see if anything leaks out and if so from where. It's supposed to hold around 8 gallons of SAE30 TO-4 oil, the same type of oil that is used in the transmission. I've seen oil leak out of those recoil compartments via the track roller bolt holes before.
Thank you Nige. I will have to pick up some of the sae30. I will let you know when I find out something
Maybe throw some cheap oil in there for a start. It would be unfortunate to find a load of expensive oil on the ground after having left the tractor overnight.
I will do that, the sae30 to-4 I found was $125 for 5 gallons. I did get a chance late yesterday to take a look at the seal on that side (part #9X-4580) and it has several large chunks missing out of it. I looked in the service manual and other than the weight (850 lbs) it did not look like it is terribly difficult to replace. I was shocked to see that the cost of that seal was $353 for one. I also checked the batteries yesterday and the terminals are loose. I am planning to get by there today to tighten those up and check the alternator output as you suggested. I will post what I find out about that.
Please post some photos of the seal with the chunks missing.
I have attached a few pictures of the seal. I think I got decent enough pictures, it was tight trying to get in the space where the missing chunks were at. It looks like the seal is missing whole sections.
Ho yas. She farked. Don’t go pouring oil in the recoil spring compartment just yet, otherwise it will simply fall out at the front. A removal and reinstallation of the front idler is in your immediate future, and I would suggest it needs to be done before the machine is operated in anger for the first time. When you replace the wiper seal it would be a good idea to inspect the fibre wear band #19 (Cat call it a bearing) that sits next to it. It may have suffered because of the lack of oil. If this side is that bad what does the RH side wiper seal look like.?
One thing I forgot to mention. There is a chromed sleeve on the “cannon” on which both the fibre bush and the wiper seal run. When you pull the cannon out check that sleeve for corrosion. There’s nothing like a corroded sleeve to tear a wiper seal to shreds.
I was thinking the same thing. I did look up the procedure for changing that seal and other than the weight of it it looks manageable. I did see the other item listed on the parts breakdown and will check those when we pull it out. I will check this as well. The portion I can see looks fine but I am not sure about what is hidden. It has not had any oil in it in a while.
The right side seal looked great, that side has no leaks and is holding oil fine.
Usually the part of the 8G-3202 sleeve (#2A) that corrodes is what is stuck out the front ahead of the wiper seal and exposed to all the dirt & moisture. Especially in your photo of the bottom LH side I can see a bit of discoloration that might well be the start of corrosion. If it was me I would tension the RH track up as tight as it will go then buff the external surface of the chromed sleeve as best as possible right back to the wiper seal, then let the track tension back off to normal. That way if the front idler on that side moves backwards on the recoil mechanism whatever slides past the wiper seal should be clean and smooth and won't tear it up. For the LH side the sleeve can be cleaned after the cannon has been removed from the track frame. I wonder if the RH wiper seal was replaced in a previous repair.?
Thank you for the advice. I did not get a chance to look at it today but I should be able to take a look at it tomorrow. I am not sure how new the right wiper seal is but it does not look very old compared to the left side. I am planning to contact Thompson tomorrow to see about getting the parts ordered to repair the left side.
If it's not too expensive I think I would suggest ordering the fibre bushing "just because" you will be removing the cannon. It may be OK but it would be a shame to get it all apart only to find the bush was worn.
Thank you, I will do that. It would be bad to put it back together and have to take it apart again.
Nige, I wanted to provide an update on the D6. We got the wiper seal and bushing and was preparing to change that out today. We started the machine with no problem and let it warm up. We had to move it about 30' to get it in the shop and it would move initially but then stopped as if the brakes were being applied. It would do this in forward or reverse. When it does this there are no lights on the dash and the serv code does not display. I am guessing that the final drive pump is bad as was stated by the Cat guy. If there is something else that I need to check I will be glad to as I believe the pump is a little over 2k.