Hello. I got an issue that I can’t figure out hopefully one of you can help me. I get power when I turn the key everything electronically works but won’t start. All the symbols in the left pod light up at first like normal then goes out including lap bar safety light and parking light even if the lap bar is up the light is off. I’m lost with this one any help is greatly appreciated. Thanks for your time.
You're going to need an electrical schematic to start tracing power. Please post the machine Serial Number. Also have you tried anything basic such as checking battery voltage, tightness of cable and ground connections, etc.?
Yes I have checked all of the first to check items and I do have a schematic but I’m stumped on this one. Model ZSA01646
Have you traced power from the START wire of the key switch (307-OR) to the start relay when the key switch is put into the start position.? What battery voltage are you seeing with the key ON.?
I have not checked that wire to the relay. I did check the for continuity between the plug and pin 14 on conn12 and the battery volts are 12.47
I will have to check the connection to the relay in the morning it’s dark out here now
Those " B " machines have had problems with the battery cables burning off internally after many years as your is not young in life from what I see. They are 2/0 cables and need to be tested for voltage drop. They are also known to have negative cables break off at the bottom of the starter mounting bolt. There is a few more things to check, but start with what Nige mentioned and don't go by what the cables look like. They burn off internally and unseen. Simon C
Just waiting for the rain to let up to check your suggestions. Thanks again for the help
Thinking about it check Simon's suggestion first.
Will do
So I got no power to the starter relay and the battery cables have no volt drop and the ground strap to the starter looks great
Which side of the relay.? From the key switch or from the battery.?
I have battery power to the relay but no power from the key ignition
Do you have power on wire 307-OR at the switch when you turn the key to the start position.? You should have permanent battery+ on wire 105-RD. You should have batt+ on wire 308-YL when the switch is moved to the RUN position. You should have batt+ on wire 307-OR when the switch is moved to the START position. This should disappear as soon as you release the key and the switch moves back to the RUN position.
I do have power at the key. When turned everything electrical works then nothing sending to the relay. Seatbelt and park lights come on when I turn the key but disappear after a few seconds regardless if the lap bar is up or down. Kind thinking it might be a security lockout
A security lockout wouldn't turn off the power to the panel AFAIK. It would simply not permit the starter to energize. If you simply turn the key to the ON position do the panel lights still go out.? It almost sounds as though something is pulling the power down to ground when you turn the key ON. Try unplugging the key switch and test it for continuity between Pins 1 & 4 in the RUN position, and between Pins 1 & 4 plus 3 & 4 in the START position.
My original issue I was having was the park brake light would flashing and I couldn’t move the machine but the loader functions worked normal. I did find that the pink and purple wires from the park switch had no continuity to conn 12 pin 22 and pin 29. But in the meantime the issue with starting by the key popped up
Based on that maybe you are going to need someone with a scanner hooked up to the machine and read the Codes. 614-PU (CONN 12 Pin 22) is the wire that supplies power for internal switch lighting (and tail lights) F780-PK (CONN 12 Pin 29) is the wire that, when connected to ground via the park brake switch, signals both the Interlock and AUX ECMs that the park brake is ON. Did you check the grounds (200 & 201-BK) at the park brake switch.? Especially 201-BK.
Yes both are good
Nige I missed your other post the panel lights come on when I put the key in the on position then go out after a few seconds. I will check the pins again when I get home today
If the lights always stay on provided the key is not moved from the RUN to the START position then the implication would be that there is something shorting power to ground when the key is moved to START.
Does anyone know if the machine has a neutral position switch or if I put direct power to the park brake solenoid would allow the machine to be pushed/pulled into my garage to work on. It’s getting to cold out to trace wires
It needs to be running with hydraulic pressure to release the brakes. There is no easy way to release the brakes .
I can get the machine to run if I jump the starter and it also turns off with the key
I can get the machine to run if I jump the starter and it also turns off with the key
Will it drive under those circumstances.?
I have not tried to send direct power to the solenoid
I did have a Cat tech come look at it yesterday but his computer wouldn’t sync to the machine so he said there is nothing he can do
View attachment IMG_6692.jpeg Pretty sure I found my gremlin
Which one is that.? Operator Interlock I'm guessing.
I believe so under your right foot. The one with a ground strap. Other side isn’t much better
No., the right side is the AUX ECM. Should be nothing to do with starting. The Operator Interlock Control is under your left foot.
Under left foot. It feels a lot heavier than the other possibly loaded with water but probably ice now it’s 25F outside
I do see pin 68 and 70 have armbar and seat going into them and pin 45 is parking brake. The inside of ecm 154-4233 actually looks really clean.
Wow, that is more than a Gremlin. Think you might be onto something. Brace yourself for the price it is worth. Simon C
Even the little computer ground strap would not likely be doing a very good job. Simon C
I found a place in Houston Texas the sell reman one for $2500 with a lifetime warranty I’m gonna call in later on today. Hopefully this fixes my issue but it look like a safe bet
The ecm that is damaged. Pin45 is the power wire for the brake switch. Pin68 is power for the seat safety switch. Pin70 is the power wire for the lap bar. I guess live and learn with these machines. I will post anything I find good or bad. Thank you all much appreciated
You may find that with all the external corrosion your ECM might not be acceptable as a core against a Reman one because it is not repairable for future sale to someone else. Best to ask the question first. There are places around that sell new aftermarket ECMs for less than half that price. Drop me a message if you are interested.
Great thanks.
Would you happen to know where I can find the serial number for the motor. All I can find is a casting mark on the left side if your looking through the door
Look for a number stamped on the top of the block right at about cylinder head gasket level. Usually it's on the LH side of the engine at the flywheel end, so that will be the RH side of the machine as you look into the engine compartment from the back. Also check for a plate/sticker on the valve cover. The original engine Serial Number installed when the machine was manufactured was CJS12552. EDIT: Should look like this .......
Well i got the ecm installed in yesterday and still the same issue
Just wanted to update everybody that viewed this thread or that might view in the future. The machine is back to normal now. I ended up replacing the aux ecm that was noticeable bad thousands spent still the same issue. I spent countless hours checking continuity and kept coming up with nothing. So I ordered the interlock ecm which actually looked to be in great shape and it solved my issue. However I did find out from someone that just the parking brake light flashing is a sign of poor signal from the interlock ecm. Thanks to everyone who joined in on my expensive journey
Glad you finally got it sorted. It is unfortunate it turned out to be such an odyssey.
Thanks. One good thing is I got a lot of knowledge on wiring now and how these machines actually work that probably would’ve cost more to go to a school to learn
You also have a good new AUX ECM that is now surplus to your requirements. There is a good market for them seeing as Cat price even their Reman ones at $4k+.
I know right. $4700 plus $1500 for core