1512D Starter Question

[mkopishke]

Well I went and checked it out. I took the glow plug indicator out of the loop, but that didn't help so I just cleaned up all it's connections and up it back in. The good news is the voltage did go up a bit, but still not enough to get the solenoid to kick.

While I was trouble shooting the indicator I noticed something odd, no fuel pump. It's getting power, it's just dead.

That's right the blasted fuel pump died on me too.

My frustration with this thing is complete. If someone walked in when I was working on it and offered my $100 bucks for it I would have handed $50 back and said sold!

So, where I'm at right now is I'm not so sure it's anything to so with the plugs. I reassembled the circuits one by one, starting with the glow-plugs. Just them alone in the start position drops the voltage down to about 11.5 volts. When I add the start circuit back in it drops down to just a hair over 11 volts. Adding AC back in doesn't really change anything. I know I should be checking amps but I don't have an amp meter big enough to test these circuits.

Is there anyone out there that would test to see what voltages reading they get when the key is in: Glow Plugs, On & Start?

Maybe some day I can get this hunk of junk going.

 

[mkopishke]

Good news!

The fuel pump lists at $188.00 from CC, WOW! That's not the good part, the good part is that from Kubota it's $64.00. The mark up CC gets on the Kubota parts is just wild.

Small battles you know.

Since I've been finding a volt here and a half a volt here with out any real gains I'm wondering it's it's just not the starter's solenoid. That would also explain why it's not happy when the tractor it warmed up. It's a pretty new starter, only a year and a half or so.

The double solenoid idea listed way back in this thread might work here.

 

[mbounds]

Matthew K: Make sure that you check that circuit breaker and the solid state V/R mounted side-by-side on the upper right side of the pedestal. If either or both are bad it can drive ya nuts. The connections on the breaker can really eat your lunch....BTDT...as both run separately through the Ignition Switch to the Solenoid!

Myron B
CCSupplyRoom

 

[mkopishke]

Hi Myron,

How do you check the V/R? I cleaned the connections on them a little while back.

The breaker, I'm assuming if the juice is flowing it's good!

The fuel pump has me a little worried though. I don't think I did anything to kill it, but it is very much dead.

thanks,

 

[mkopishke]

Some more playing today, thank god I'm not paying myself by the hour, I sure would be expensive!

So, with the starter completely removed (I'm going to have it tested) I thought I would trace some more. The interesting thing I found is that the switch in the start position I measured the voltage on the battery side and it was at 11.8 volts (12.3 sitting with everything off), that doesn't seem to be all that bad considering that's with the glow plugs kicking and all.

This time I pulled the plug on the PTO switch (first in line after the key switch) and measured the voltage there and only found 10.5 volts.

The big difference this time is that I tested the key while it was still installed.

The other thing I found was that when the key was in the start position, not hooked up the battery and not hooked up to the starter, I was getting continuity from the positive batter wire to the switch it's self (that is I bumped it with the lead and heard *beep*).

Could it have been the key all along?

 

[jorr]

Any luck with the key? I am having this identical problem with my 782D.

 

[mkopishke]

Nope.

Another 30 bucks down the hole.

I've got 12 volts going into the switch and under 10 coming out (I'm measuring at the disconnected PTO safety switch plug, which is the first thing after the key switch).

I can jump the switch, hold the thing in the start position and then push the button on my "jump circuit" and it will fire right up.

I am very tempted to just get a 12v solenoid, have that at the end of my start circuit with the juice going to the starters solenoid coming on a short hop from the big post on the starter. Make sense? It's not fixing the problem, it's a solution.

I'm going to take one last stab at it though. I've pulled the battery tray right out so I can see what's going on. The trick now is hooking up the battery. I was using jumper cables but it's not perfect.

 

[bbranstetter]

Matt,

Had a similar problem with my Father in Laws 3184. Thing would start fine with a direct hot wire from the battery to the solenoid but going through the key switch to the solenoid I was getting a 5 volt drop. Turns out even though the solenoid was working fine, there was enough current draw to pull the voltage down and roast a new key switch.

Here is a link to the thread if there is anything that would help ya. Good luck!



http://tinyurl.com/5c9bfz

 

[mkopishke]

Thanks Brian,

The weird thing here is that I'm getting the voltage drop with the starter solenoid disconnected, ie no load on the circuit. Unless you think my brand new switch was toasted too?

The only other thing on at that time is the glow plugs, which if I test the voltage with just them on there's a slight drop, but not much. I know they're pulling a bunch of amps though.

I really wish I had an amp meter that could handle more then 10 amps.

Like I said I'm going to really tear into it tonight. I know from the fire safety switch (PTO) to the start solenoid is good, but I'm going to disconnect EVERYTHING else and see where it gets me.

 

[mkopishke]

Anyone want to do me a BIG favor?

What's the resistance of the glow plugs at room temperature on your machines?

You will have to remove the wires to get a true test.

After a ton of testing tonight I'm leaning towards the glow plugs again. Take them out of the equation and everything works like a charm.

Thanks!

 

[dcurran]

Sorry I didn't read this sooner. However, I have your answer, and it's cheap!

http://s142.photobucket.com/albums/r91/FancyBob_2007/Cub%20Pics/882/Glow%20Plug%20Conversion/

That album shows my wiring changes on the Kubota. The fault is in the design. Originally these engines used fixed voltage glow plugs. The glow plug heating coil was designed as a buffer against burning them up. That occured over 13V. The new spec ones areNGK Y-103V's. Kubota part #15951-6551-3

The pics I have labeled and tagged, if you have questions, ask. Otherwise, I'll try and sit down and write up something.

My tractor has gone through 2 PA winters on the same case magnum bat. With no charging. Almost 2700hrs on it. And it's stored in a detached lean-to.

 

[mgonitzke]

David C.-

Would you mind providing some details about this? My 782D needs glow plugs fairly soon.

 

[mkopishke]

Well....

I'm going to sounds VERY stupid here.

I was putting everything back together to load 'er up and drop it off at the local starter shop (he said he could find the problem in 10 minutes) and thought, well lets check all the connections again. Went through the grounds, they all were still clean but I had a Roloc disk in my grinder so I hit them all again. Really no change, I had them shining before but since I went through the effort to take the grounds out why not.

I went to put the battery back in and looked at the positive connector, looked clean, always has, but I thought what the heck lets hit it with the Roloc disk since I had it right there.

I hit the key and I thought I broke something. The starter never spun so fast.

I swear up and down that the thing was clean, I mean I've seen so much worse work fine. Best I can tell is that there's so much draw everything just has to be perfect.

So there it is.

The real test will be if it starts after I get everything good an hot. That will happen next week when I mow the lawn. I suspect it's going to be fine though.

I've been kicking myself all day, the EASIEST connection to get to!!!

 

[bbranstetter]

Thats great

! I hope that is the ultimate fix. Did you go with a good quality dielectric grease to coat all the connections that you repaired? I don't always do that and usually get burnt down the road on that one. I'm always in a hurry. Let us know.

 

[mkopishke]

I did, although a few of those connections probably need another application due to all the unplugging/plugging.

It's funny, I thought I would be so happy when I found the problem, then it turned out so simple that I'm mad at my self.

We will see after I mow.

 

[dcurran]

Matt, basically what I did is removed the orange wires from the indicator. tied them together and pig-tail'ed them to the pos on the LED indicator light. I also Ran another wire to the switch terminal on the starter relay I bolted on top of the fan bracket. A fresh power wire from the bat to the relay, and the other terminal to the glow plugs.

Due to advancements/costs these plugs have their own built in voltage regulation. The older type and once most common plugs used a fixed voltage, max output. When engine started and bumped the voltage up 1.5~2 volts, it would fry them. Now that's not possible. So using the pre-heat coil indicator is a HUGE waste of amps. Plus The way the voltage traveles through the switch either uses one or both terminals on the switch, based on wether the key is held left, or right. Add in 20+ years of corrosion and too small of wire gauge for amp draw(45A@12VDC) you had a lot of heat waste. I now have no more of that. It doesn't matter how long I hold the key in pre-heat, I can't burn the plugs out. Plus, even in the winter, the most I need to hold it for is 15 sec. This puppy fires up like a brand new Kubota G series.

Oh, also a couple of things. Any fuel pump rated under 7~8 psi will work. I had an old autolite sitting around I used to replace it. Also get yourself a quart of diesel kleen in the gray bottle. add a cap full or 4 to a 5 gal can of diesel. That'll do wonders for the fuel system, and clean out all the gunk in the pintles/hats/needls/pump/etc. Plus it displaces moisture, great for prevention of alge- a huge risk if using bio-diesel.

 

[mkopishke]

Well, turns out I didn't fix it with the connection cleaning. What it ended up being is the positive battery cable. Everything looked good externally, connections were clean and the casing didn't have any damage.

Cutting the casing back (was going to install new ends) showed corrosion all the way down the cable, what a mess!

So, I after cutting the old cable out of the harness (Hey CC, why did you do that?) and then having the local auto electric shop make a new cable it is consistently starting well now. The glo-plugs react faster and the the starter turns faster and stronger then I can remember.

So, not all CC Diesel starting problems are ground related.

Two years of chasing a ghost! Some times it would start fine, sometimes it would not. Couldn't figure out what changed.

I hope it stays fixed now...

K