Cat 246c Won't Start

[Simon C]

Once you have verified if the starter cranks with good cables or booster cables used as by-pass you will need to find out if you have clean power to the White wire at solenoid. I do not have the method to retrieve codes on " C " models, only on D models. You could have a relay problem or a signal to relay problem that is controlled by the engine ECM. I may have the schematic for this unit, have to check it over. Nige sent it to you. Start with the first tests and see what you find.
Simon C

 

[Simon C]

Correct me if I'm wrong Simon C, but the acceptable voltage drop on either the positive or negative battery cables is generally 0.5 volts or less. If the voltage drop is more than that, you will want to look to fix a poor connection (loose or corroded) or replace the cable.

Sorry I did not respond sooner ThreeCW. You are correct that at 0.5 loss of potential, there is going to be starting and other control problems. On the ground side it seems to be worse especially on body or frame grounds that computers send power back to the battery, it is very important. From positive of battery to solenoid Positive on starter it can go to about maximum 0.7-0.8 D.C.volts loss of potential. Some start systems use smaller cables which equates to more loss than others.
When you find 10.5 volts loss on the ground cable like I found yesterday, its a no brainer. Cable junk.
Hope that helps. Any questions fire away.
Simon C

 

[Simon C]

Almost forgot that Nige posted in number 11 above of the need to fix the oil pressure wire. That would produce codes is my guess and what exactly the computer would do with no signal from it is maybe your problem. However the starter still has to crank something with live power to the Starter "S" terminal even without computer signal so start there after fixing the wire.
Simon C

 

[Nige]

ET is not limited to dealers. Is there a local independent around your way that can hook up ET and do a scan for you.?

 

[mjones35]

Can someone tell me if any of these relays in the fuse box is the starter relay? There are only three relays that are actually present - 1, 3, and 4 counting up from the bottom left. I drew arrows next to them. I'm not sure about the symbols.

 

[Nige]

The attached may be of some help. You should really get yourself an Operation & Maintenance Manual (Cat Publication reference SEBU8019), all this info and more besides is in it. See HERE

 

[mjones35]

Thanks. I have the Service and Repair manual but it doesn't have higher level physical info like this. I'll definitely get the O&M manual today. I don't see anything like a starter relay listed though. There is an "ignition switch" fuse under the cab and it checked out okay. Are there other relays other than the ones in the main fuse panel?

 

[Nige]

I have the Service and Repair manual

Genuine OEM.? I assume not because a genuine OEM Service Manual would contain a copy of SEBU8019.

 

[Nige]

Are there other relays other than the ones in the main fuse panel?

All you have to do is search the pdf of the schematic for the word "relay". It will pop up every hit.

 

[mjones35]

I found the relay on the schematic. I just can't find it physically on the machine.

 

[Simon C]

Did find how to get codes out of monitor on your machine from what I know. Would be good to check or print a copy and have in machine to refresh the memory.
Simon C

 

[Simon C]

I found the relay on the schematic. I just can't find it physically on the machine.

I think you can click on the relay and find the location on the pictorial of the machine. I do not have that schematic but have many others. Nige supplied most of them.
Simon C

 

[mjones35]

I think you can click on the relay and find the location on the pictorial of the machine. I do not have that schematic but have many others. Nige supplied most of them.
Simon C

You're right. I thought the diagram was just pointing to the starter, but I think it's pointing to a relay behind the starter.

 

[mjones35]

Did find how to get codes out of monitor on your machine from what I know. Would be good to check or print a copy and have in machine to refresh the memory.
Simon C

Unfortunately, my machine doesn't seem to have this right-side screen. Must have been added later. Thanks for looking that up though.

 

[Nige]

You're right. I thought the diagram was just pointing to the starter, but I think it's pointing to a relay behind the starter.

If you're talking about #30 then the line from the number 30 doesn't go far enough. The relay is mounted on the flywheel housing just behind the starter.

Actually your starter relay might have been moved. See the Service Mag article SEPD1234 attached.

 

[Simon C]

If you're talking about #30 then the line from the number 30 doesn't go far enough. The relay is mounted on the flywheel housing just behind the starter.

Actually your starter relay might have been moved. See the Service Mag article SEPD1234 attached.

View attachment 347631

Must be the heat and vibration causing problems for the relay. Good you knew about it.
Simon C

 

[Jointery]

CanDo used to make an affordable handheld scanner that would read CAT ecm codes (and others). It does not have the ability to set or reset thresholds, pressures or perform other programable functions. Nor can it see historical data stored in the ecm. Its a code reader only. Be sure to thoroughly explore online pricing, capability and software support before buying any of these products…

 

[mjones35]

CanDo used to make an affordable handheld scanner that would read CAT ecm codes (and others). It does not have the ability to set or reset thresholds, pressures or perform other programable functions. Nor can it see historical data stored in the ecm. Its a code reader only. Be sure to thoroughly explore online pricing, capability and software support before buying any of these products…

Thanks. I'm seeing the current version of their product out there for around $350. Still checking the reviews.

 

[mjones35]

If you're talking about #30 then the line from the number 30 doesn't go far enough. The relay is mounted on the flywheel housing just behind the starter.

Actually your starter relay might have been moved. See the Service Mag article SEPD1234 attached.

Thanks for finding this. It appears that mine is in the original location. I've detached it for testing and will reinstall it in the new location on the other side of the mount and rotated 90 degrees.

 

[mjones35]

I haven't determined the electrical problem yet that is causing no power to be sent to the starter solenoid. That problem started only after I had been testing the starter. I hope it turns out to be the relay because I have another one of those.

It does appear that my original problem is that the starter is bad. I can't even get it to engage if I run power directly from the battery to the starter power connection and solenoid. I'm also grounding directly to the battery. I'm at a standstill now because I can't remove the starter. I removed the three mounting nuts, the main power connection, and the solenoid wire. I'm now unable to break it free. I've tried breaking it free with a prybar with no luck. Are these things usually this difficult to break free? I don't want to damage the flywheel or anything. Any suggestions appreciated.