5045E Wiring/Diagnostic Guide

[Jeffrey Bandel]

I did that a long time ago.

 

[workinonit]

And? What was the result? Sounds to me like you may have 2 problems. A bad starter and something amiss in the starting circuit.

 

[Jeffrey Bandel]

The starter is bad

 

[workinonit]

Who woulda thunk it.

 

[Jeffrey Bandel]

Got the starter out and bench tested it and it works. I could not get it to spin on the tractor. Now I'm stumped.

 

[Tx Jim]

Starter not operating when installed but operating when bench tested is typical for tractor having poor battery cables or poor battery cable connections

 

[Jeffrey Bandel]

Brand new battery and brand new negative cable. I tested them for continuity just to be sure. When I tried jumping the starter from my truck, the positive on the starter, alternator and battery all measured at 14.5 volts.

 

[workinonit]

Brand new battery really means nothing. I've had multiple bad, brand new batteries before. Reading static voltage on a battery also tells you nothing. Measure that voltage as you turn the starter over. Load testing things is the only way to know you have a good power source and good connections.

 

[Jeffrey Bandel]

It's not the battery. Please trust me on that.

 

[workinonit]

So on a bench test the starter spins fine. Install said starter and short the terminals and the starter won't spin. That my friend is a bad battery or a bad connection somewhere between the battery and the starter. Or.....the starter is intermittent. The only reason we harp on these things is because we've seen it on this forum 100 times.

 

[Jeffrey Bandel]

That battery started my diesel truck by itself and my truck has two batteries. That was how I loade tested it. The battery is fine.
If the cables between battery and starter measure the same voltage, how can the cable be bad? Not trying to argue but I don't understand what you're saying.

 

[workinonit]

I'll give you a real life example. I'm installing a voltage regulator on a gas turbine in Reno right now. The contractor finished the wiring install and we were doing site acceptance testing. My field voltage signal comes from a wire that is attached to the DC bus with a 1/4" - 20 bolt. I would read full field voltage when we ran the regulator until I introduced my load bank and voltage would drop to almost zero. After searching I found they had not tightened the bolt to the bus and my signal would go away when I loaded it down. IE, bad connection.

Does that make sense?

 

[Jeffrey Bandel]

That makes sense. When I tried the starter when it was on the machine I brought 14.5 volts to the starter from my battery directly via jumper cables. The starter wouldn't even spin a little. Is it possible the internals of the starter were shorting out inside the starter?

 

[workinonit]

I suppose, or maybe bolting it to the tractor frame is somehow putting it in a bind? I know that's a reach but honestly what you are describing isn't making any sense to me. One of my Flukes and a few minutes at the tractor and I would find the issue. It's hard to troubleshoot from a distance.

 

[Jeffrey Bandel]

It's wierd. I have replaced 4 bad starters this year in different machines. All were standard diagnostics.

 

[beenthere]

Jeff
Are you running a repair shop or have that many machines?

 

[LD1]

Following along.

But what is the voltage at the BIG stud at the starter WHILE you are jumping it to the S-terminal (trying to engage the starter).

It could STILL be a bad battery cable.

Eluding to what was tried to be explained earlier about how you can show 14.5 but wont crank.....

Look at your battery cable.....probably a hundred little strands of copper wire right?
Now imagine all but ONE is broken. That tiny little strand can conduct and show you voltage on your meter at the starter....but aint got a snowballs chance in h3ll at cranking that tractor over. Put a load on it and the voltage drops out.

Thats why I want to know the voltage when trying to JUMP the starter similar to your bench test.....but with it installed on the tractor.

 

[Jeffrey Bandel]

Just a farm.

 

[Jeffrey Bandel]

For clarity: When I tried to jump the starter I bridged the big post on the starter (solenoid) to the "s" terminal. Nothing. Next I hooked up jumper cables to my truck and to the tractor battery and did the same thing. Nothing. Next I went straight from my truck to the big post on the starter with jumper cables and bridged again. Nothing. On the bench I had an old battery. I wired from the negative battery post to the frame of the starter. Then I wired from the positive of the battery to the big post on the starter. I hooked up a separate wire from the battery positive and touched the "s" terminal and it spun.

 

[LD1]

Repeat the test I describe. Bridge the large stud and S terminal and see what the voltage on the big terminal drops to.

Simply playing musical jumper cables and saying it didnt do anything doesnt tell us a thing. You could have an issue with the ground cable just as easily as the positive.

And by moving the Positive jumper cable straight to the starter post is meaningless unless you ALSO moved the negative jumper cable directly to the starter frame. Then you essentially are repeating your "bench test" with the starter simply bolted to the tractor rather than flopping around on the bench.

I am still suspecting a cable or connection issue and none of your troubleshooting has proven otherwise