Cat 963c two speed not working moves slow

[Nige]

If you were only losing speed signal only on one side it might be worth a try to swap sensors side to side to see if the loss of speed signal changes sides or stays where it is.

I dunno but I would say that if you have a speed signal not reading it could have everything to do with your loss of top speed issue.

FWIW I would not ohm those particular wires to check continuity. If you have a wire somewhere hanging on by a thread then it could show "good" on a resistance check but not be good enough to pass a signal. I prefer unplugging the connectors at both ends, jumper one end of wire X to machine frame ground, then power the other end of the same wire from batt+ using a fused 3A or 5A test light. If the wire will pass that level of current it should be good.

 

[pittsburgh cat man]

I was mostly concerned about getting a speed reading to check the track motors destroking. I seem to remember checking speed sensors with volt meter using spoons into connector with meter set to ac milli volts

 

[pittsburgh cat man]

I keep thinking both sides not reading or partial reading makes me think a connector that has both speed sensor wires in it.

 

[Sbird]

Update got everything back together and tested machine again still no speed register in any the submodes and now have a new code 079-0132.03 ?

 

[1466IH]

I would have to go back and read systems operation again but I am pretty sure that the speed signals tell the controller how far to open the solenoid valves in the control valve so I wouldn't think it would move at all.

 

[Nige]

now have a new code 079-0132.03 ?

Override pressure sensor. See attached.

 

[1466IH]

I keep thinking both sides not reading or partial reading makes me think a connector that has both speed sensor wires in it.

Having just replaced the harness on a 2DS00624 there is no connection between the speed sensors and the power train controller. Those wires branch off about 18" from the controller connector and run right down the RH side of frame and then splits off with one going to RH sensor and the other half gets tied to bottom of frame to the LH sensor. I will say that when I ordered that harness there are several serial # breaks so I can't say if his would be the same or not.

 

[Sbird]

Override pressure sensor. See attached.

Well that was easy fix simply unplugged pressure sensor cleaned connection and cleared code I washed it yesterday to get better look at things guess got moisture in that plug

 

[Sbird]

Guess back to trouble shooting speed sensors for now I will see what I can find what is the likelihood of bad ecm ?

 

[Nige]

This from the electrical schematic at the ECM. The track speed sensors go to various Pins on Connector B. The wires go through one major harness connector between the finals and the ECM. Look for CONN 14 on the schematic.

 

[Sbird]

Found new issue retesting speed sensors found on b plug on ecm the e900 and e901are in b20 and b14 on plug but e903 yellow is in b23 and e 902 purple wire is in b29 this book shows should be in b24 and b35

 

[Sbird]

Is it possible to switch them or is this possibly just not correct for my machine

 

[pittsburgh cat man]

So I knew I had a speed sensor I decided I would do a little testing I connected my meter to it set meter at ac volts 200m worked a small set of calipers in front of pick up it will read

 

[pittsburgh cat man]

Just had another thought the 7x6315 strap on Nige's ecm post is a little braided strap that connects ecm case to one of the mounting bolts might be a good idea to check it as ecm is mounted in rubber

 

[Nige]

Found new issue retesting speed sensors found on b plug on ecm the e900 and e901are in b20 and b14 on plug but e903 yellow is in b23 and e 902 purple wire is in b29 this book shows should be in b24 and b35

I would believe the schematic, especially if there is no obvious indication that the wires on Connector B have ever been interfered with in any way.

Is it possible to switch them or is this possibly just not correct for my machine

The sensors you mean., Sure it is, they are the same Part Number. Just switch them side for side, set up the adjustment correctly and see if the problem stays where it is or follows the sensor that's currently reading 0.0.RPM.

 

[1466IH]

If you are swapping sensors I believe the engine speed sensor is the same also. I am assuming he reading his engine speed via the display so which would mean we know that sensor is working correctly.

 

[Nige]

If you are swapping sensors I believe the engine speed sensor is the same also.

Same Part Number.

 

[Sbird]

That’s what I was thinking it looks like same sensor might try swapping it and see if I can get reading that way ! I tested wires from ecm to sensor like you mentioned nige and they test good all way to ecm plug but still no reading was looking back at testing procedure I’ve been skipping first test unplug sensor and test from plugs to side case said should get reading of 10000 or higher I get nothing but test across the plug prongs shows good ?

 

[Nige]

I’ve been skipping first test unplug sensor and test from plugs to side case said should get reading of 10000 or higher

In truth you should get open circuit. On my meter it shows as "OL".

 

[Sbird]

That’s what mine says also