Cat 259D3 Intermittent Starting Problem

[Bucky4444]

259D3 Compact Track Loader
Machine Serial Number - CW909973
Machine Build Date - 2021/01/26


Great site for info and I have gotten much help in the past searching the posts, but I couldn't find the help I needed this time, so first time posting.

As I said in the title, the machine sometimes starts and sometimes it doesn't. It will go through the normal boot up sequence and the info screen displays normally, but when I turn the key to start it - nothing. It can happen the first time of the day or after a shutdown or anytime. When it does start, there is no common thing that I've been able to pinpoint as to why. Sometimes I'll try it after about an hour after it won't start, sometimes it's a day or two.

I know I'm missing something simple to check, but I don't have a schematic and haven't found one yet.
This is what I've checked thus far:

Arm interlock and harness connection - OK (verified with an ohmmeter)
Seat interlocks and harness connections - OK (verified with an ohmmeter)
Battery connections - OK (removed, cleaned and reconnected)
Starter connections - OK (removed, cleaned and reconnected)
Ground straps - OK (removed, cleaned and reconnected)

Thanks for your help in advance!!
Bucky

 

[Simon C]

You could have a start relay that is not getting powered up, Could be the starter itself, could be simple cable or switch. Just for your info, you cannot test any of the big cables on OHM scale as 1 strand of wire remaining from A-B will test perfect but will not run. How many hours on this unit. Is the ribbon heater working, although not a likely cause if engine is warm. Any fault codes on the display. Have all the filters been serviced. When you say nothing happens, do any relays click, Does the engine crank or not crank when this happens. Give a little detail and maybe we can help.
Simon C

 

[Nige]

I don't have a schematic and haven't found one yet.

You do now. Check your message inbox.

 

[Bucky4444]

Almost 1000 hrs. No fault codes. Not sure what or where the ribbon heater is, but it does start (when it feels like it) whether cold or warm. Just did the 1000 hr. service about a month ago and this started after that.

No crank - turn the key and nothing happens - no clicking sounds and the display stays up without so much of a blink.

 

[HarleyHappy]

Any possibility that something you did on the 1k hour service caused this intermittent starting?
Loose connection?

 

[Nige]

Do you recall touching any of the battery connections during the PM.?

Do you have an infra red temp gun.?

 

[Bucky4444]

Don’t think I did anything wrong on the service but I suppose anything is possible. And I definitely didn’t come near the battery.

I do have a temp gun. What do I check with it?

 

[Bucky4444]

Oops need to clarify. I was definitely near the battery changing the oil filter & fuel filter but didn’t make contact with the positive terminal and didn’t leak anything onto it.

 

[Nige]

I do have a temp gun. What do I check with it?

This will require the services of a second person. Take a close look at all the battery cable connectors in the illustration below, especially the one at the positive battery terminal where two cables are crimped into a common connector. Do you see any signs of localized heating when the key is turned to the start position.?
An infra red camera would be really good for this but you're not likely to have one of those handy.

 

[Bucky4444]

Thanks. I have access to one. I will check it out.

 

[Nige]

There have been numerous cases (thanks to @Simon C) of battery cables appearing fine on an external inspection but are corroded/severed internally, or almost so.

 

[Bucky4444]

Here's sort of an update. Due to other commitments, I didn't get back to the machine yesterday to check the temps & other things suggested. However, first thing this morning I tried to start it - just as I have been doing every time I went near it since this thing has been acting up - and it started without hesitation! It's been idling normally for about 30 mins. now. I'm headed back over to shut it down and attempt repeated restarts and perform the other checks. I'll keep you posted...

 

[Simon C]

You can have a cable on its way out, or it should be atleast ruled out. Can you try these simple tests to rule out a few cables. Will need 2 people or a recording meter.

#1 - Stab the positive post with your Red meter lead and the Positive post of the starter Solenoid (where the big Red Cable is attached) with the Black meter lead. What does the meter read with the key turned to start while starting or while held there and not starting. Anything over 0.8 volts is a problem in the connection or cable.
#2 - Stab the negative post with your Black test lead while holding the Red test lead on clean steel of the starter body while someone is starting or holding the key in the start position even if it does not start. What is the meter reading in DC volts? Anything over 0.5 volts is a bad ground cable or bad connection.
#3 - Stab the frame on clean steel with the Red test lead lead and the Black lead on Battery Negative post while doing test as above. What does the meter read in DC volts. Anything over 0.5 volts means a poor frame to battery negative connection.

Take a picture of these instructions and take to machine and rule out these possible problems.
Please report back what you found or figured out.

Simon C

 

[Simon C]

Just for your information I once found a burnt positive cable at the battery, was brand new 50 hours on the Screw Compressor, looked perfect and would not even put on the dash lights. Crimped on a new end and all good. You cannot tell with your eye if burnt inside,
Simon C

 

[Bucky4444]

OK, here's an interesting twist. The machine would not start when I went back out this morning to shut it down and attempt restarting. (about 45 mins. of running time) My neighbor threw a thought at me and said maybe something is heating up and keeping it from starting. Apparently he had similar problem with his truck years ago but couldn't remember what the problem was.

Well, I thought it can't hurt so I got out the hose to give it a good dousing. If nothing else, at least I can hose out the condensers and radiator. OK, call me even more confused - yes it started after dropping the engine temp from 176F to about 124F. My neighbor is smiling like a butcher's dog at this point!

Ok, gotta try this again - run to operating temp and try a restart, then cool down and restart. I actually did it 2 more times and yes each time the machine did not restart at operating temp but did after a cool down. I'm even more confused now........

 

[Arny L]

I agree with Simon, about doing voltage drop test on cables. Electrical resistance increases with an increase in temperature. Your decreasing resistance when you cool engine down.

 

[Simon C]

About post # 13 above, I found a similiar serial number but not exact schematic and if your positive cable from battery goes direct to starter as the schematic I have then in test # 1 even 0.5 DC volts of loss would be a faulty cable.
Both of the ground tests should be maximum about 0.4- 0.5 volts DC.
You will have to test eventually.
Simon C

 

[HarleyHappy]

Starting to think you have a bad cable, either positive or negative but also a possibility that the starter solenoid is taking a crap.

 

[Bucky4444]

Sorry, haven't had the time to check the cables. Just wanted to let you know since I haven't responded in a few days. I may get to it today.

 

[Bucky4444]

Sorry guys, I know it's been a while. Ok, here's the latest...

Cables were temp tested and did not get hot. I measured the cables with a meter and all readings were at or less than those stated above. As said earlier, all battery, starter, & ground connections were removed & cleaned. Yet, the machine still had fits of not starting at various times, sometimes even when cold. And then it wouldn't start at all, regardless of temp or time of day. For 4 days I tried and tried to no avail.

Frustrated, I called Cat to send out a mechanic. He connected a laptop and verified no codes or errors were shown. He verified the arm, seat, & door sensors were ok and not the problem. He checked the start relay by replacing it & took apart several other control wire connectors to check for corrosion or loose connectors. As you may guess - no affect.

Next he tapped on the starter/solenoid with a long bar and it started. Shut it off several times and it started each time. Drove it around bouncing it pretty good and when it was shut down, it wouldn't start. Got the bar out and banged the started again and yes, it started.

So long story short, it appears the starter may have been the culprit all along. They want $400-500 to change it, so I'm going to do it myself. I'll let you know the reults when I get it changed.

Thanks to all for the help and troubleshooting thoughts. Lots of great information gained that I'll be adding to my maintenance/repair journal.